From a structural point of view, corrugated board would fit on the category of sandwich structures, which in sectors as aeronautics or construction are today commonly analysed using simulation tools that are based on the Finite Element Method. However, in spite of similarities to applications in other materials, FEM simulation of corrugated board is a high challenging modelling task due not only to the need of addressing properly the complex mechanical modelling of paper itself, but also because of phenomena that are directly related to the corrugated structure, as the relationships between local and global instability failure modes. The present paper, through a set of application examples, shows how different Abaqus modeling capabilities (SC8R elements, composite sections, connector elements, …) can be applied for solving the different difficulties that arise when modelling corrugated board. The integration of these capabilities has led to the development of virtual prototypes for the two most common corrugated board packages: B1 boxes and agricultural trays. From the experience in these box types, and taking advantage from the inherent modelling simplicity of the composite layered models together to the flexibility offered by the available modelling techniques in Abaqus, these virtual prototypes have been extended as a design tool for very different types of corrugated board packages.
Numerical and Theoretical Analysis for Investigation of Shear strength of A J...ijsrd.com
It is becoming increasingly important to accurately predict the behavior of adhesive joints. Adhesive joints are widely used in industries e.g. automobiles, aircrafts, home appliances and so on. They are being used as a closure system in the packaging industry, through the use of adhesives as a system for construction of complex structures such as skyscrapers, airplanes, trains or buses etc. In adhesive bonding, the load is transmitted from one adherend to another adherend smoothly through the adhesive layer in the overlap region i.e. the adhesive serves as medium for load transmission. The research is presented with variants of different adhesive materials proposed for the shear strength investigation of adhesive joint to be used in the automotive industry. The problem is investigated using mathematical analysis as well as analytical methodology with Finite Element Analysis. For meshing of the geometry of the brake shoe assembly hyper mesh software is used. In FEA, the competent software ‘Abacus’ is used for determining the shear stress induced in two different materials of adhesive layer applied to the brake shoe. Different variants with different adhesive materials and geometry of base material are analyzed for concluding the research work.
Optimisation of Welds with Manufacturing ConsiderationsSIMULIA
Fatigue is the main in-service failure mode for automotive chassis & suspension parts, especially weld fatigue. Over the years, Tata Steel Automotive Engineering (TSAE) has developed techniques for CAE durability assessment including the optimisation of seam-welded chassis/suspension structures. Seam weld optimisation at TSAE has previously been based on a constant weld length and constant gap between welds for each weld run. This method has two drawbacks; weld patterns generated are regular in nature, reducing the flexibility to position welds where they are most effective and• excessively short welds are often left at the end of a run of welds. The objective was to develop an improved optimisation technique using Isight that always produced a manufacturing feasible design and allowed more flexible and irregular positioning of welds. Manufacturing constraints considered were minimum weld length, minimum gap length and minimising the number of start/stop operations. To reduce the number of design variables, a new load-case-weighted optimisation scheme was developed using a single weighting factor for each load case. These factors were used to generate weld patterns by scaling the strain energy density in finite elements from an initial fully welded design. Weld elements were selected for retention/deletion by comparing a weighted sum across all load cases with a threshold value. During each optimisation, Isight varied the weighting factors as “design variables” to minimise overall weld length, while achieving stiffness and fatigue life targets. The process has been extended to function for laser weld designs where an intermittent weld pattern is generally the most effective.
Analysis of R.C Deep Beam by Finite Element MethodIJMER
ABSTRACT : The analytical study of reinforced concrete simply supported deep beams subjected to two point loads was
carried out using finite element method to study the behavior of deep beam by considering flexural stress, flexural strain,
and shear stress variations at different sections for various effective lengths to depth ratio and compared with EulerBernoulli Theory. The effective span to depth ratios of the beams considered were 1.25, 1.375 and 1.5
Keywords: Finite Element Method (FEM), Reinforced Concrete (R.C) deep beam, Shear strength.
Numerical and Theoretical Analysis for Investigation of Shear strength of A J...ijsrd.com
It is becoming increasingly important to accurately predict the behavior of adhesive joints. Adhesive joints are widely used in industries e.g. automobiles, aircrafts, home appliances and so on. They are being used as a closure system in the packaging industry, through the use of adhesives as a system for construction of complex structures such as skyscrapers, airplanes, trains or buses etc. In adhesive bonding, the load is transmitted from one adherend to another adherend smoothly through the adhesive layer in the overlap region i.e. the adhesive serves as medium for load transmission. The research is presented with variants of different adhesive materials proposed for the shear strength investigation of adhesive joint to be used in the automotive industry. The problem is investigated using mathematical analysis as well as analytical methodology with Finite Element Analysis. For meshing of the geometry of the brake shoe assembly hyper mesh software is used. In FEA, the competent software ‘Abacus’ is used for determining the shear stress induced in two different materials of adhesive layer applied to the brake shoe. Different variants with different adhesive materials and geometry of base material are analyzed for concluding the research work.
Optimisation of Welds with Manufacturing ConsiderationsSIMULIA
Fatigue is the main in-service failure mode for automotive chassis & suspension parts, especially weld fatigue. Over the years, Tata Steel Automotive Engineering (TSAE) has developed techniques for CAE durability assessment including the optimisation of seam-welded chassis/suspension structures. Seam weld optimisation at TSAE has previously been based on a constant weld length and constant gap between welds for each weld run. This method has two drawbacks; weld patterns generated are regular in nature, reducing the flexibility to position welds where they are most effective and• excessively short welds are often left at the end of a run of welds. The objective was to develop an improved optimisation technique using Isight that always produced a manufacturing feasible design and allowed more flexible and irregular positioning of welds. Manufacturing constraints considered were minimum weld length, minimum gap length and minimising the number of start/stop operations. To reduce the number of design variables, a new load-case-weighted optimisation scheme was developed using a single weighting factor for each load case. These factors were used to generate weld patterns by scaling the strain energy density in finite elements from an initial fully welded design. Weld elements were selected for retention/deletion by comparing a weighted sum across all load cases with a threshold value. During each optimisation, Isight varied the weighting factors as “design variables” to minimise overall weld length, while achieving stiffness and fatigue life targets. The process has been extended to function for laser weld designs where an intermittent weld pattern is generally the most effective.
Analysis of R.C Deep Beam by Finite Element MethodIJMER
ABSTRACT : The analytical study of reinforced concrete simply supported deep beams subjected to two point loads was
carried out using finite element method to study the behavior of deep beam by considering flexural stress, flexural strain,
and shear stress variations at different sections for various effective lengths to depth ratio and compared with EulerBernoulli Theory. The effective span to depth ratios of the beams considered were 1.25, 1.375 and 1.5
Keywords: Finite Element Method (FEM), Reinforced Concrete (R.C) deep beam, Shear strength.
Warpage simulation of manhole cover using auto cast x softwareLaukik Raut
Designing an appropriate gating/risering system, some defects can be minimized such as cracks, distortion, shrinkage
porosity, warpage, sink, and shrinkage cavity by simulating the directional solidification using casting software. In this study, the
component from industry i.e. manhole cover is leading to premature failure of warpage or distortion. Hence, there is requirement
of optimizing the appropriate gating/risering system. In this paper, the actual gating/risering system is simulated to minimize the
warpage defect occurring in the industry while manufacturing. Hence, the simulation for optimizing better gating/risering system
is done by using AutoCAST-X software which is based on Vector Gradient Method (VGM) for defect minimization
Effect of lamination angle on maximum deflection of simply supported composit...RAVI KUMAR
In this project a composite laminated beam is studied with glass-epoxy and graphite-epoxy combination. The beam is composed of four layers of different combination of composite material (glass epoxy and graphite epoxy composite). The beam is simply supported at both the ends and is subjected to uniformly distributed load along the length. Transverse deflection is computed for different lamination angle (0^0-〖90〗^0) by using Euler- Bernoulli’s theory (or CLPT). Maximum transverse deflection analysis is carried out using derived analytical expressions. The research carried out in this project will enable to determine the beam strength due to bending loads. The importance of fibre reinforcement in the manufacturing of the beam is studied in terms of bending strength of the beam. MATLAB codes are generated to implement analytical expiations of the composite beam.
The main objective of the paper is to find out the lamination angle at which minimum deflection is obtained & to find out the effect of lamination angle on maximum transverse deflection of the beam.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Optimization of Multi Leaf Spring by using Design of Experiments & Simulated ...IJMER
This work carried out on a multi leaf spring of a tractor trolley with maximum load
carrying capacity of 5 Tones. The CAD model of this MLS has been modeled in CATIA V5. After
successfully preparing the CAD model, MLS is then tested in Static Structural Analysis workbench for
stress and deflection computations. The finite element analysis of the leaf spring has been performed by
converting the model into number of nodes and elements and then applying the relevant boundary
conditions under the static loading conditions. After implementation of FEA it was observed that the red
area close to shackle was undergoing maximum value of stress. This observation leads us to the
workbench of Knowledge ware and this aided us in studying the response of crucial output parameters of
MLS in the form of Stress and Deflection via Design of experiments. DOE paved the way for SAA where
optimization was carried out in order to reach the minimal stress. The corresponding values of camber
and leaf span were recorded for minimal stress
Warping and Residual Stress Analysis using the Abaqus Interface for MoldflowSIMULIA
Residual stresses may be introduced into plastic parts produced by the injection molding process. As a result, the part may warp or experience a reduction in strength. The design of an injection molded product can be improved if the effect of residual stresses on the final shape and performance of the product are predicted accurately. Abaqus and Moldflow can be used for this purpose. The residual stresses generated by the solidifi-cation of the plastic material are computed by Moldflow and transferred to Abaqus using the Abaqus Interface for Moldflow. The component can then be structurally analyzed with Abaqus to determine warpage and/or response to in-service loading. In this Technology Brief, this methodology is demonstrated with two case studies.
A memory stack on logic 3D IC stack was considered for comparative study of warpage response to two different process choices, namely, Die to Die (D2D) and Package to Die (P2D) assembly. Process and reliability modeling software CielMech, and Commercial Finite Element Analysis (FEA) software ANSYS Mechanical were utilized to simulate thermo-mechanical effects of sequential chip attach, underfilling and encapsulation process steps for the chosen flows. Warpage at room temperature as well as attach temperature after each attach step were compared. Results indicated that underfill, substrate, and mold compound thermal strains play important roles in warpage evolution. Significant differences in the final assembled state warpage was predicted and is attributable to path dependence of warpage evolution.
Multi-Physics Analysis of a Refractory Metal ACOperated High Temperature Heat...SIMULIA
Electrically operated high temperature furnaces and reactors are used in many industrial manufacturing processes such as sintering or single crystal growth in order to allow for the required process conditions. In view of their outstanding characteristics refractory metals are ideally suited as materials for the resistive heating elements. Nevertheless, significant and lifetime- limiting irreversible deformations of these elements can be frequently observed which are assumed to be caused by a combination of temperature expansion, electromagnetic forces, and high temperature creep effects. In order to study this undesired behavior, a multi-physics model of a particular three-phase AC heating element of a sintering furnace is formulated and implemented within Abaqus. It accounts for the primary involved coupled physical mechanisms such as the harmonic electrical field problem, the thermal problem governed by Joule's law, thermal expansion, high temperature creep and harmonic forces caused by the electromagnetic field along with field dependent constitutive behavior. Since in general solving the fully coupled problem on a 3D domain is computationally demanding and Abaqus lacks functionality in the field of electromagnetism, a semi-analytical approach for consideration of time-harmonic electromagnetic forces within mechanical analysis is developed in the present work. The model implemented as a userdefined extension for Abaqus is computationally very attractive since it avoids discretization of the medium surrounding the heater. Furthermore, some aspects of modeling coupled physical problems of different characteristic time-scale are briefly discussed. Results from application of the model are in good qualitative agreement with in-situ observations and confirm the relevance of considering electromagnetic forces within analysis of high temperature furnaces.
Metal welding processes are employed in various indus-tries. Gas welding techniques use the heat from a flame to melt the parts to be joined and a filler material simulta-neously. Extreme thermal loading is applied to the parts being joined, and complex material responses are initi-ated. The steep, localized thermal gradients result in stress concentrations in the welding zone. Consequently, modeling and simulation of welding processes are often complex and challenging. In this technology brief the use of Abaqus for this class of problems is discussed and an example analysis is presented.
More Related Content
Similar to Design of Different Types of Corrugated Board Packages Using Finite Element Tools
Warpage simulation of manhole cover using auto cast x softwareLaukik Raut
Designing an appropriate gating/risering system, some defects can be minimized such as cracks, distortion, shrinkage
porosity, warpage, sink, and shrinkage cavity by simulating the directional solidification using casting software. In this study, the
component from industry i.e. manhole cover is leading to premature failure of warpage or distortion. Hence, there is requirement
of optimizing the appropriate gating/risering system. In this paper, the actual gating/risering system is simulated to minimize the
warpage defect occurring in the industry while manufacturing. Hence, the simulation for optimizing better gating/risering system
is done by using AutoCAST-X software which is based on Vector Gradient Method (VGM) for defect minimization
Effect of lamination angle on maximum deflection of simply supported composit...RAVI KUMAR
In this project a composite laminated beam is studied with glass-epoxy and graphite-epoxy combination. The beam is composed of four layers of different combination of composite material (glass epoxy and graphite epoxy composite). The beam is simply supported at both the ends and is subjected to uniformly distributed load along the length. Transverse deflection is computed for different lamination angle (0^0-〖90〗^0) by using Euler- Bernoulli’s theory (or CLPT). Maximum transverse deflection analysis is carried out using derived analytical expressions. The research carried out in this project will enable to determine the beam strength due to bending loads. The importance of fibre reinforcement in the manufacturing of the beam is studied in terms of bending strength of the beam. MATLAB codes are generated to implement analytical expiations of the composite beam.
The main objective of the paper is to find out the lamination angle at which minimum deflection is obtained & to find out the effect of lamination angle on maximum transverse deflection of the beam.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Optimization of Multi Leaf Spring by using Design of Experiments & Simulated ...IJMER
This work carried out on a multi leaf spring of a tractor trolley with maximum load
carrying capacity of 5 Tones. The CAD model of this MLS has been modeled in CATIA V5. After
successfully preparing the CAD model, MLS is then tested in Static Structural Analysis workbench for
stress and deflection computations. The finite element analysis of the leaf spring has been performed by
converting the model into number of nodes and elements and then applying the relevant boundary
conditions under the static loading conditions. After implementation of FEA it was observed that the red
area close to shackle was undergoing maximum value of stress. This observation leads us to the
workbench of Knowledge ware and this aided us in studying the response of crucial output parameters of
MLS in the form of Stress and Deflection via Design of experiments. DOE paved the way for SAA where
optimization was carried out in order to reach the minimal stress. The corresponding values of camber
and leaf span were recorded for minimal stress
Warping and Residual Stress Analysis using the Abaqus Interface for MoldflowSIMULIA
Residual stresses may be introduced into plastic parts produced by the injection molding process. As a result, the part may warp or experience a reduction in strength. The design of an injection molded product can be improved if the effect of residual stresses on the final shape and performance of the product are predicted accurately. Abaqus and Moldflow can be used for this purpose. The residual stresses generated by the solidifi-cation of the plastic material are computed by Moldflow and transferred to Abaqus using the Abaqus Interface for Moldflow. The component can then be structurally analyzed with Abaqus to determine warpage and/or response to in-service loading. In this Technology Brief, this methodology is demonstrated with two case studies.
A memory stack on logic 3D IC stack was considered for comparative study of warpage response to two different process choices, namely, Die to Die (D2D) and Package to Die (P2D) assembly. Process and reliability modeling software CielMech, and Commercial Finite Element Analysis (FEA) software ANSYS Mechanical were utilized to simulate thermo-mechanical effects of sequential chip attach, underfilling and encapsulation process steps for the chosen flows. Warpage at room temperature as well as attach temperature after each attach step were compared. Results indicated that underfill, substrate, and mold compound thermal strains play important roles in warpage evolution. Significant differences in the final assembled state warpage was predicted and is attributable to path dependence of warpage evolution.
Multi-Physics Analysis of a Refractory Metal ACOperated High Temperature Heat...SIMULIA
Electrically operated high temperature furnaces and reactors are used in many industrial manufacturing processes such as sintering or single crystal growth in order to allow for the required process conditions. In view of their outstanding characteristics refractory metals are ideally suited as materials for the resistive heating elements. Nevertheless, significant and lifetime- limiting irreversible deformations of these elements can be frequently observed which are assumed to be caused by a combination of temperature expansion, electromagnetic forces, and high temperature creep effects. In order to study this undesired behavior, a multi-physics model of a particular three-phase AC heating element of a sintering furnace is formulated and implemented within Abaqus. It accounts for the primary involved coupled physical mechanisms such as the harmonic electrical field problem, the thermal problem governed by Joule's law, thermal expansion, high temperature creep and harmonic forces caused by the electromagnetic field along with field dependent constitutive behavior. Since in general solving the fully coupled problem on a 3D domain is computationally demanding and Abaqus lacks functionality in the field of electromagnetism, a semi-analytical approach for consideration of time-harmonic electromagnetic forces within mechanical analysis is developed in the present work. The model implemented as a userdefined extension for Abaqus is computationally very attractive since it avoids discretization of the medium surrounding the heater. Furthermore, some aspects of modeling coupled physical problems of different characteristic time-scale are briefly discussed. Results from application of the model are in good qualitative agreement with in-situ observations and confirm the relevance of considering electromagnetic forces within analysis of high temperature furnaces.
Metal welding processes are employed in various indus-tries. Gas welding techniques use the heat from a flame to melt the parts to be joined and a filler material simulta-neously. Extreme thermal loading is applied to the parts being joined, and complex material responses are initi-ated. The steep, localized thermal gradients result in stress concentrations in the welding zone. Consequently, modeling and simulation of welding processes are often complex and challenging. In this technology brief the use of Abaqus for this class of problems is discussed and an example analysis is presented.
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The inspection and screening of flaws in high explosive filled gun fired projectiles are crucial to ensure safety for soldiers using these items. In bore failure of structural components are sure to produce lethal consequences, therefore it is of great importance to determine what the maximum permissible crack size is for a given component coming off of the production floor. The analytical process to determine critical flaw size occurs in two stages. First, ABAQUS Explicit finite element analysis code is used to conduct interior ballistic simulation of a 40mm shape charge projectile. The modeling scope includes interior gun tube geometry with drive band engraving and spin up effects. Pressure load inputs, which were derived from live fire test data, are used to drive the model. Secondly, the explicit model results are passed to NASGRO software for critical flaw size determination using linear-elastic fracture mechanics theory. The modeling information and approach to the problem will be presented in this paper as well as explicit model results and proposed inspection criteria.
Earth Penetration Simulation using Coupled Eulerian-Lagrangian AnalysisSIMULIA
In earth penetration events the projectile generally strikes the target at an oblique angle. As a result, the projectile is subjected to a multi-axial force and acceleration history through impact. The effectiveness of an earth penetration system is enhanced by the ability to withstand severe lateral loading. Consequently, it is important to understand how such loads develop during an impact event. In this Technology Brief, Abaqus/Explicit is used to simulate the impact of a high-strength steel penetrator into a concrete target. The penetrator/target interaction is analyzed using the coupled Eulerian-Lagrangian methodology. Specifically, the penetrator is modeled in a traditional Lagrangian framework while the concrete target is modeled in an Eulerian framework. It will be shown that Abaqus/Explicit results are in good agreement with published experimental data.
Coupled Euler Lagrangian Approach Using Abaqus /Explicit in the Bird Strike A...SIMULIA
Bird impact damage in complex aircraft structure has been investigated using explicit transient dynamic analysis by Abaqus/Explicit in order to fully employ its large library of elements, material models and the ability of implementing user defined materials. The numerical procedure has been applied on the very detailed large airplane secondary structure consisting of sandwich, composite and metallic structural items that have been modeled with 3D, shell and continuum shell elements, coupled with appropriate kinematic constraints. Bird has been modeled using Coupled Euler Lagrangian approach, in order to avoid the numerical difficulties connected with the mesh. The impact has been applied in the area that is the most probably subjected to the impact damage during the exploitation. The application point and velocity vector have been varied and the comparisons between total, kinetic, internal and damage energies have been performed. Various failure modes, such as CFRP face layer rupture, failure of composite matrix, damage initiation / evolution in the Nomex core and elastoplastic failure of a metallic structure have been investigated. Besides, general contact has been applied as to efficiently capture the contact between impactor and structure, as well as large deformations of the different structural components. Visualization of failure modes has been performed and damaged area compared to the available references. Compared to the classic Lagrangian modeling of the bird, the analysis has proven to be more stable, and the results, such as and damage areas, physically more realistic.
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Design of Different Types of Corrugated Board Packages Using Finite Element Tools
1. Visit the SIMULIA Resource Center for more customer examples.
Design of Different Types of Corrugated Board
Packages Using Finite Element Tools
M. A. Jiménez-Caballero, I. Conde, B. García, E. Liarte
Instituto Tecnológico de Aragón
C/ María de Luna 7-8, 50007 Zaragoza. SPAIN
www.ita.es
Email of corresponding author: majimenez@ita.es
Abstract: From a structural point of view, corrugated board would fit on the category of
sandwich structures, which in sectors as aeronautics or construction are today commonly
analysed using simulation tools that are based on the Finite Element Method. However, in spite
of similarities to applications in other materials, FEM simulation of corrugated board is a high
challenging modelling task due not only to the need of addressing properly the complex
mechanical modelling of paper itself, but also because of phenomena that are directly related to
the corrugated structure, as the relationships between local and global instability failure modes.
The present paper, through a set of application examples, shows how different Abaqus modelling
capabilities (SC8R elements, composite sections, connector elements, …) can be applied for
solving the different difficulties that arise when modelling corrugated board. The integration of
these capabilities has led to the development of virtual prototypes for the two most common
corrugated board packages: B1 boxes and agricultural trays. From the experience in these box
types, and taking advantage from the inherent modelling simplicity of the composite layered
models together to the flexibility offered by the available modelling techniques in Abaqus, these
virtual prototypes have been extended as a design tool for very different types of corrugated board
packages.
Keywords: Corrugated Board, Packaging, Box Compression,
1. Introduction
FE-based simulation has been increasingly used in the last decades as the main structural analysis
tool in many different industrial sectors and, in combination with other numerical techniques and
tools as CFD, has been also the main basis for the more recent concept of “virtual prototypes”
replacing manufacturing and testing of physical components. Starting in the past from civil
engineering, aeronautics and automotive industry, present applications of finite element simulation
extend to any industry sector as electronics, medical equipment, packaging, and more specifically
corrugated board packaging. In general terms, compression strength can be considered as the
most important requirement of a package, or at least the one that is common to all package types,
as during transport and storage, any box has to support without damage the weight of the rest of
the supported boxes; thus, initially, corrugated board industry has considered FEM as a possible
2009 SIMULIA Customer Conference 1
Visit the SIMULIA Resource Center for more customer examples.
2. tool for replacing the traditional application of semi-empirical expressions (Mc Kee et al. 1963)
looking for both, improved accuracy in the prediction of box compression strength using
numerical simulation of the package (Gilchrist et al. 1999, Rahman 1997, Urbanik et al. 2003,
Biancolini et al. 2003), and extending the analysis to package types as different as possible.
The introduction process of FE in corrugated board industry has been slower than in other sectors,
probably because of the very complex mechanical behaviour of both, paper itself and corrugated
board, leading to models that require very specific material models or advanced FE techniques.
However, and in spite of the slow start-up, applications of FEM to corrugated board industry are
rapidly growing, somehow taking advantage of previous developments in advanced modelling of
composites and composite sandwich structures, with relevant similarities to corrugated board. The
present paper summarises the general aspects of the simulation methodology that the authors are
applying for the structural analysis and design of corrugated board packages. The objective of the
paper is to provide a general description of the practical capabilities of the developed simulation
methodology, showing how Abaqus can be applied in the development process of corrugated
board packages, but without entering into detailed descriptions of a given finite element model or
simulation, nor presenting geometry and paper composition details of analysed packages.
2. GENERAL METHODOLOGY FOR FINITE ELEMENT SIMULATION
OF CORRUGATED BOARD
2.1 Modelling the mechanical behaviour of paper
Resulting from the manufacturing process, paper is an orthotropic material with very different
mechanical properties in each of the three principal material orientation directions (Baum et al.
1981): through thickness direction (ZD), in-plane direction parallel to rolling during processing,
referred as machine direction (MD), and the in-plane direction normal to MD, referred as cross
direction (CD). Apart from orthotropy, paper behaviour exhibits two additional characteristics
that prevent from application of simple materials models: a) highly non linear behaviour, b) large
differences between tensile and compressive responses in any of both, MD and CD. Figure 1
shows the characteristic shape of the stress-strain curves in MD and CD.
stress
Tensile curve in MD
Tensile curve in CD
Compressive curve in CD strain
Compressive
curve in MD
Figure 1. Characteristic stress-strain curves of paper in machine direction (MD)
and cross direction (CD).
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3. Of course, paper behaviour exhibits additional characteristics that increase additionally the level of
complexity of modelling, as exhibiting significant creep, humidity dependence of mechanical
properties, higroexpansion, … In any case, it is important to remark that orthotropy, non-linearity
and differences tension-compression play all an important role even in the simple case of BCT
testing of a package under controlled room conditions, and because of this, mechanical modelling
of paper, even for the simpler loading cases always rely on the availability of a user developed
material model implementing as many as possible from the three referred characteristics plus
specific features for handling other property dependences if required by specific application (Xia
et al. 2002, Isaksson et al. 2004, Mäkela et al. 2003, Alfthan et al. 2005). In the examples that are
next presented, an in-plane orthotropic damage model with different treatment of tension and
compression and including definition of final paper failure according to the Tsai-Wu criterion
(Tryding, 1994) has been applied for modelling the static response of paper in the short-term using
shell elements; the model has been implement through UMAT and VUMAT user subroutines,
only shell element versions, in Abaqus/Standard and Abaqus/Explicit, while the required
transverse shear stiffness values for the shells are calculated using the out-of-plane shear elastic
moduli from the constituent papers. The model has been validated at paper level through
validation from ECT (edge crush test) and FCT (flat crust test) experimental results (Jiménez et al.
2003, Bielsa et al. 2006).
Figure 2 summarises as example the validation of the paper material model by simulating in
Abaqus/Explicit a FCT test of a single flute board by means of a single wave model in which
symmetry boundary conditions are applied in all the edges given the large dimensions of the FCT
sample (100 mm x 25 mm) when compared to the single wave. Results show how three
experimental load peaks can be identified along the test with deviations around to 10%. As
already expected when designing these validation tests, the differences in displacement prediction
are higher because of different reasons, including among these the simplifications in the modelling
of the adhesive and of the out-of-plane behaviour of the paper
1600
Symmetry conditions for modelling a
100mmx25mm FCT sample
1400
C3D8R elements for FCT test
adhesive Simulation result
1200 Total failure
extension
1000
Load (N)
800
Failure progression
600
Failure initiation
at creases
400
200
C3D8R elements S4R elements for liners 0
for adhesive 0 0,5 1 1,5 2 2,5
and fluting
Displacement (mm)
Figure 2. Comparison of simulation and experimental results for FCT simulation of
single flute paperboard.
2009 SIMULIA Customer Conference 3
4. As it will be presented in forthcoming parts of the paper, carrying trays for agricultural products
present, in addition to BCT qualification, another key requirement in terms of the so called
“bottom sag” under sustained load or creep. This requirement is established in terms of
displacement instead of strength, as the limit structural condition is determined by the possibility
of the bottom of a given try touching and damaging the fruits or vegetables that are packaged in
the box underneath. In order to cover creep, the material model of paper has been modified for
considering viscoelastic strains under sustained loads. The selected model is based on Coffin
equation for paper creep (Coffin, 2005) that considers potential and logarithmic behaviour (see
equation 1) and fulfils the needed conditions leading to the possibility of creating master curves
for paper through a logarithmic time shift in stress values (Brezinski, 1956). Coffin equation for
the creep modulus, J, is shown in Equation 1.
J
(t ) 1
0 E
1 A 1 e at B ln bt 1
1
The first term represents primary creep, which is considered a delayed response where A is the
inverse of elastic modulus of the delayed response, a is a time scale factor and is the exponent of
the potential behaviour observed for short times. The second term represents secondary creep and
is based on Brezinski´s observation that long term creep is a lineal function of logarithm of time. B
is a creep flow parameter and b is a time scale factor. Figure 3 shows results from simulation of
patch tests with a single shell for tensile creep at different percentage of tensile failure stress,
together to results of the experimental creep tests that were used for determining the parameters of
the corresponding creep equation; results correspond to a recycled paper to be used as linerboard.
2.50E-10
2.00E-10
J (1/Pa)
1.50E-10
1.00E-10 — 10%
— 20%
— 40%
5.00E-11
— Simulation
0.00E+00
0 50000 100000 150000 200000 250000 300000 350000
Tiem po (s)
Figure 3. Results of creep characterisation of a sample paper and validation of
user creep model for paper through tensile patch test
The modelling methodology that is proposed by the authors for BCT simulations and analysis of
box bottom sag (including creep) is based on Abaqus/Standard simulations, mainly because of
higher computational efficiency for most of the analysed cases. In any case, during the initial
stages of the methodology development, Abaqus/Explicit was also used from to time to time for
very specific simulations, as an easier way to extend analysis beyond specific instabilities as those
in the FCT example that has been previously presented (Figure 2).
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5. 2.2 Simplified laminated composite models
Modelling of the corrugated structure using 3D shells for liners and fluting, as in the example
shown in Figure 4, is not realistic when thinking of virtual prototyping for efficient material
selection or analysis of geometry variations. Efficiency problems of 3D shell-based modelling of
corrugated shape are not only related to computation times for the whole package but also to
modelling details of complex package areas as corners and flaps; in addition, it must be noticed
that strength analysis of paperboard requires non-linear FEM analysis due to the importance of
instabilities, so requiring some computational effort. Thus, detailed FEM models of corrugated
board structures, like the ones that are shown in Figure 4, are useful for estimating some
corrugated board properties that are difficult to be measured experimentally, but are not yet
realistic for the modelling and simulation of the whole package when thinking of a large variety of
package types. It is important to remark here that simulation difficulties are not only related to
computational effort but also to the complexity of geometrical modelling.
Single fluted board Doubled fluted board
2
3 1
Figure 4. Pictures of single flute and double flute corrugated board and
corresponding 3D-shells models with detailed flute geometry
For modelling purposes, corrugated board can be simplified to a laminated structure with
alternative “thin” layers of non-corrugated liners, and “thick” layer consisting of a corrugated
paper flute. Hence, corrugated board is defined structurally as a sandwich structure with a
non-continuous core, like other well-known sandwich structures as composite sandwich panels
with honeycomb cores. Thus, a first step for simulation is translating the actual corrugated core
geometry to a set of equivalent mechanical properties to be associated to a continuum core,
therefore allowing simulation through any of the different techniques that are used for sandwich
structures (with technique selection depending mainly on sandwich thickness): layered solids,
layered thick shells, layered continuum shells, or combinations of previous approaches. Several
methods can be found in literature for minimising the errors in the in-plane and flexural
behaviours that are related to the simplifications for establishing the equivalent flue properties
(Luo et al. 1992), as well as for estimating transverse shear equivalent properties (Nordstrand et al.
1997) for the equivalent structure. In the examples in this paper, estimation of transverse shear
stiffness is performed from simulations of detailed corrugated geometry models as in Figure 4, as
modelling of a flat panel for determination of equivalent properties is easy to be parameterised and
automated, even if not suitable for the modelling of the final package.
2009 SIMULIA Customer Conference 5
6. Once an equivalent material for a continuous core is considered, the most cost-effective element
type for corrugated board is usually a S4R thick-shell with proper accounting for transverse shear
stiffness. Of course, other approaches exist for modelling corrugated board, as using solid
elements for the core or using layered solid elements (C38R for instance) instead of layered shells,
but some modelling issues, as keeping suitable aspect ratios in the solid elements or reaching to
the required number of through thickness solids for proper accounting of transverse shear, require
usually quite large computational models. However, as it is later presented when discussing
bottom sag, such approaches are sometimes required to improve modelling results.
Next, Figure 5 shows an example of the CD stresses in a liner for a non-linear buckling analysis of
a corrugated board panel. Results on the left correspond to a detailed FE model with modelling of
flute geometry using S4R elements, while results on the right have been obtained from a
simplified composite shell model, using a single layer of S4R with a *COMPOSITE section
definition, using equivalent core properties. It is required to remark that detailed modelling of the
corrugated medium implies some restriction for the mesh size in the liners, so in the example of
Figure 5 it is also interesting to note the much coarser mesh size while maintaining the significant
stress values (compressive ones) below a 6% difference with regard to the detailed model, which
is a quite low value considering non-linear buckling analysis.
Figure 5. Comparison of CD stresses between detailed model including corrugated
flute geometry and equivalent composite model.
In spite of its simplicity, the application of simplified composite models gives rise to an added
problem when thinking of failure prediction: a detailed model with flute geometry, as the one in
the left part of Figure 5, could be directly applied for prediction of local instabilities in the case
that the mesh size is properly selected (see Figure 6), but analysis of local bucking in a simplified
model without considering corrugation shape is not so simple.
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7. Figure 6. Detailed FE model for local buckling prediction.
As already mentioned, the Tsai-Wu failure criterion is possibly the most usual for paper strength
analysis. Nevertheless, when paper is used as part of corrugated paperboard, the failure criterion
has to take into account also local buckling as a possible failure mode for the liners, at loads
significantly lower than those for strength failure. The alternative way for considering local
buckling in simplified models that is followed by the authors consists of combining the Tsai-Wu
strength criterion with an additional criterion related to local instability. This approach requires
for each different corrugated board specific determination of such instability criterion either by
analytical or numerical tools (Nyamn et al 1999, Biancolini et al. 2003), as this depends on the
specific geometry of the supporting corrugation wave. The development and validation of the
proposed simulation methodology has been supported by a large experimental program, not only
at package level, but also in previous development stages through in-plane compression tests of
rectangular corrugated boards using lateral supports for preventing global buckling at low loads.
2.3 Selection of element type
As already mentioned, equivalent composite models are not limited to layered shells but can
include combinations of different elements, as for instance, shells for liners with solids for the
core, or even layered solid without shells. Like in any FE simulation, the selection of the right
element is critical. As an example of the relevance of element selection, a numerical and
experimental study for the selection of the most adequate element type for modelling bending in
corrugated board panels was carried by the authors (Jiménez et al. 2004). Bottom sag analysis of
box bottom requires simulation of bending, and therefore, transverse shear stiffness may play an
important role. Not all the element types that can be used for modelling an equivalent laminate
consider transverse shear behaviour with the same accuracy, neither all of them are able to take
into account possible thinning of corrugated board. The results of the study indicated that a very
simple model of composite linear thick shells with reduced integration (S4R) using simplified
continuum-equivalent properties for the fluting is the most efficient solution for single flute
corrugated board; however, when double fluted boards are of interest, as it is usually the case in
carrying trays, importance of shear transverse stiffness and thinning of paperboard increase
significantly, being highly recommended the using of at least four layers of composite reduced
integration continuum shells (SC8R). Figure 7, from the referred study, illustrates the difference
between a single flute board and a double flute one. The first graph shows how the composite
shells capture corrugated board stiffness very accurately in a single flute board, the second one
2009 SIMULIA Customer Conference 7
8. shows how the same elements behaves too stiff when a double flute is analysed, finally, the third
one shows how using four layers of composite continuum shells (SC8R) solves the problem.
Figure 7. Comparison of flexural stiffness prediction capabilities for different types
of equivalent composite models.
3. Application to papers selection in B1 boxes and agricultural trays
3.1 Simulation of BCT test
The BCT (box compression test) value is the most usual property for qualifying package
performance in corrugated board packages. It consists of the maximum achieved load level under
quasi-static compression of the package between two rigid plates in a universal testing machine
under controlled temperature and humidity room conditions. Regarding package functionality, the
BCT value refers to the package capability to withstand the weight of the rest of the stack over it.
Figure 8 shows an image of a finite element model for simulating the BCT test of a B1-type box,
also referred as american box; it includes the final damaged areas together to a picture of a tested
sample, showing very good correlation in terms of predicting failure mode.
Figure 8. Comparison of BCT simulation with experiment.
8 2009 SIMULIA Customer Conference
9. The finite element model for the simulation in Figure 8 consists of S4R elements with layered
composite definition for the corresponding *SHELL SECTION and definition of connector
elements (type=CONN3D2) for the corner lines. The section behaviour of these connector has
been defined after experimental characterisation of the torque/angle behaviour of the folded lines
for the corresponding boards, following recommendations from studies on other paperboard
packages (Beldie et al. 2001). JOIN and REVOLUTE behaviours in the connector section
definition, in combination with the NONLINEAR option in *CONNECTOR ELASTICITY, are
applied when it is required to define non-linear behaviour.
For the examples presented in the paper, connector elements are always selected instead of other
means to accomplish the connection as multipoint constraints. Model sizes are not too big and
therefore the higher efficiency of multi-point constraints is not a key factor, while connector
elements combine very high versatility in connection behaviour with easy definition and they
allow very easy modification of connector type and behaviour details during the initial stages of
model development and validation.
The larger complexity of the BCT model for a B1 box is the definition of the contacts between
box flaps and between these and compression plates (Figure 9 shows an example of a magnified
global buckling behaviour of the top part of a box, with some flaps removed for displaying
purposes). Analysis involves combination of local material failure with global instability,
therefore non-linear geometric analysis is required. Because of the relevance of the global
buckling behaviour when analysing BCT, it is important to account for geometric imperfections of
the box; in the examples in this paper, this was accomplished by using the option
*IMPERFECTION with mode shapes from a previous eigenvalue buckling modes estimation
using *BUCKLE.
Figure 9. Finite element model of B1 box (two of the top flaps are removed for
displaying purposes) with magnified deformation to show global buckling.
2009 SIMULIA Customer Conference 9
10. While it is usual that B1 boxes allow symmetry modelling in height (as the model in Figure 9,
only for the top half of the box), carrying trays as AGRIPLAT and PLAFORM types for
agricultural products allow one-quarter symmetry models (see Figure 10). However, modelling of
the corner areas adds certain complexity to the modelling tasks, requiring also to keep good
control of material orientation definitions. Modelling of glue lines in corner areas and flaps can be
also carried out by using connector elements.
AGRIPLAT type box
CD material dir.
MD material dir.
Detail of material orientation
One-quarter
PLAFORM type box
symmetry FE
models
Figure 10. FE models of carrying trays for agricultural products, including a
example material orientation definition details
Figure 11 illustrates how the FE simulation of a PLAFORM type carrying try is used for analysing
which is the effect in BCT value and failure mode of using two possible considerations for
including a carrying hole in the try lateral side, the first option considers such hole as additional to
the venting hole in the bottom line, while the second one just enlarges the venting hole to the
required size for placing easily the hand. Figure 11 illustrates also how the simulations have been
validated experimentally, not only in terms of BCT load value, but also in terms of damaged areas
and failure mode.
10 2009 SIMULIA Customer Conference
11. Double hole: venting and carrying Single larger hole with double function
Figure 11. Validation of prediction of global failure areas in PLAFORM type box
with different geometry for venting and carrying holes
Simulations following the proposed methodology present an error with regard to experimental
BCT values that is usually below 10% in terms of maximum load, which can be considered a very
low error if the complexity of material behaviour and failure mode (combining local buckling and
strength failure) is put together to other simulation details as torque-angle behavior of folded lines,
definition of glue lines, or non-linear analysis involving global buckling. Validation of all model
details for different packages has required a large experimental effort with monitoring of many
different variables during the test, as out-of-plane displacement of package faces or application of
high speed cameras for identifying onset of local buckling. Figure 12 shows an example of the
experimental set-up during the initial testing program for model development of agricultural trays.
BCT plate
LVDTs
Acquisition system
for LVDTs
Acquisition system
for LVDTs
Data cable from
universal test rig
Computer Lighting Camera
2009 SIMULIA Customer Conference 11
12. Figure 12. Experimental set-up for detailed BCT analysis to provide data for FE
model development and validation
3.2 Simulation of bottom sag in agricultural trays
The bottom sag of agriculture carrying trays can be studied with the presented
composite models since they reproduce flexural rigidity of corrugated board accurately in
the loading range of interest (Jiménez et al. 2004). The strength requirements from BCT
are increased now with stiffness ones; the objective in the design is to avoid excessive
displacements that would cause the tray bottom to contact with the products in the box
below (what happens at load levels well below ultimate bottom sag strength), so requiring
consideration of creep displacements after initial load application.
In the example corresponding to the simulation in Figure 13, the tests were performed
on a PLAFORM carrying try, measuring the displacement in the centre of the bottom.
The load was applied by means of bags filled with of golf balls so that load is distributed
in the box bottom. Simulation consisted of one unique step using the procedure
*STATIC and specifying the real duration of the test. Load application in time was
controlled by means of an *AMPLITUDE procedure. The material model included the
Coffin model for paper creep already commented in previous points of this paper.
Comparison of simulation results to experimental ones for the creep displacement shows
a good approximation to prediction of creep displacements. Although it exists a
difference in the total predicted displacement value, this is related to the large initial
compliance showed during the experimental process of loading application, because of
the trays not being perfectly flat, and so with uneven support along test rig.
8
(m) 7
6
Displacement (mm)
Desplazamiento(mm)
S4R elements
5
4
3
3
2
1 SC8R elements 2
Test 1 1
Ensayo
1 Test 2 2
Ensayo
Simulation
Simulacion
0
0 2000 4000 6000 8000 10000
Time (min)
Tiempo (min)
Figure 13. Simulation of bottom sag in agricultural creep and comparison to
experimental results in terms of displacement increase in time
12 2009 SIMULIA Customer Conference
13. 4. Examples of application to other package designs
FEM simulation of corrugated board is not limited to B1 boxes or agricultural tries. Using
simplified-composite linear 3D shells is usually sufficient for most types of analysis, and because
of this, modelling of almost any package becomes a relatively straight task. Figure 14 shows
simulation and test results corresponding to a corrugated ring that is used as reinforcement in the
packaging of washing powder. FE results show a very good prediction of the failure mode.
Contact with upper
plate for BCT test
Unconnected
Unconnected nodes for
nodes for modelling of
modelling of stepped cuts
stepped cuts
Modeling of
gluing lines with
MPCs
Contact with
lower plate for
BCT test
Figure 14. Simulation of BCT of corrugated inner ring for reinforcement of washing
powder packaging
Evolution of markets and packaging personalisation generates continuously new
package types, for which corrugated board remains as a cost-effective and
environmentally friendly solution. One of the new corrugated board package types of
highest commercial interest is the ready-to-sell one. Using of stepped cut along box faces
facilitates removal of the top half of the package; therefore, the same package can be used
first for transport and later for showing the product in the store shelves, just using quick
removal of top part of the package without the need of taking out one by one the products
inside. Figure 15 shows how an Abaqus models that has developed for analysing how the
presence of stepped cuts modifies failure mode in comparison to the uncut package.
Modelling of the stepped cuts is carried out using unconnected nodes in combination to
connector elements for taking into account contact along cut line. The model has been
applied for analysing the influence of different designs of the stepped-cuts in the final
BCT performance, as the objective is to keep this in the highest possible value while
assuring easy opening of the box without tearing outside provided cut lines.
2009 SIMULIA Customer Conference 13
14.
Simulation of stepped die-cuts
Conecto
rigidez
by means of connector elements
along unconnected node lines
Figure 15. FE model of ready-to-sell box for analysis influence of stepped-cuts
design on BCT performance
5. Conclusions
Because of their broad range of simulation procedures and element types, together to
the large possibilities offered by user subroutines, Abaqus provides the required
framework for the development of a virtual prototyping framework for the corrugated
board industry. Presented results show that Abaqus application offers possibilities
ranging from selection of constituent papers or flute geometry, to detailed design of
package geometry for a set of given performance requirements.
Although it has not been referred in the present paper, FEM in general, and
particularly Abaqus thanks to its advanced features, offers to the paperboard industry
other possible applications as analysis of board manipulation processes for package
production, or even prediction of macroscopic paper performance from microstructure
details resulting from manufacturing process.
6. References
1. J. Alfthan, P. Gudmundson. “Linear constitutive model for mechano-sorptive creep in paper”.
International Journal of Solids and Structures, 42, 2005.
2. L. Beldie; G. Sandberg; L. Sandberg, “Paperboard packages exposed to static loads-finite
element modelling and experiments“ Packaging technology & science, vol. 14, 2001.
3. Brezinski, J. P. “The creep properties of paper”. Tappi Journal 39(2), 1956.
4. G.A. Baum, D.C., Brennan and CC .Habeger, Orthotropic elastic constants of paper, Tappi
Journal, Vol. 64, 1981.
14 2009 SIMULIA Customer Conference
15. 5. M. E. Biancolini and C. Brutti, “Numerical and experimental investigation of the strength of
corrugated board packages”, Packaging Technology and Science, Vol. 16(2), March 2003.
6. J.M. Bielsa, R. Rodriguez, L. Vila, M. A. Jiménez, “Parametrized finite element analysis of
tribological instabilities on polymer-metal sliding contacts”, III ECCM, Lisbon 2006.
7. Coffin, D. W., “The creep response of paper”, 13th Fundamental Research Symposium,
Cambridge, 2005
8. A.C. Gilchrist, J.C. Suhling, T.J. Urbanik. “Nonlinear finite element modeling of corrugated
board”. Mechanics of Cellulosic Materials, 1999, AMD-Vol. 231/MD-Vol. 85, 1999.
9. P. Isaksson, R. Hägglundb,P. Gradina. “Continuum damage mechanics applied to paper”.
International Journal of Solids and Structures, 41, 2004.
10. M.A. Jiménez, I. Conde, E. Liarte, E. Mozas. “Modelling of bending in a corrugated board”,
International Paper Physics Seminar, Trondheim 2004
11. M.A. Jiménez, E. Liarte. “Simulation of the Edge Crush Test of corrugated paperboard using
Abaqus”, Abaqus World Users Conference 2003, Munich.
12. P. Mäkelä, S. Östlund. “Orthotropic elastic–plastic material model for paper materials”.
International Journal of Solids and Structures, 40, 2003.
13. R.C. Mc Kee, J.W. Gander, J.R. Wachuta. “Compression Strength Formula for Corrugated
Board”. Paperboard Packaging, Aug 1963
14. T. Nordstrand, L.A. Carlsson, Evaluation of Transverse Shear Stiffness of Structural Core
Sandwich Plates, Composite Structures, Vol. 37, 1997.
15. U. Nyman, P.J. Gustafsson, “Local buckling of corrugated board facings, Proceedings of the
European Conference on Computational Mechanics”, Munich 1999.
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Materials AMD-Vol. 145/MD-Vol. 36, 1992.
17. A.A. Rahman. “Finite Element Buckling Analysis of Corrugated Fiberboard Panels”. ASME
Symposium on Cellulosic Materials, AMD-Vol.221, 1997, Evanston.
18. J. Tryding, A modification of the Tsai-Wu failure criterion for the biaxial strength of paper,
Tappi Journal, Vol. 77, 1994
19. T.J. Urbanik, E.P. Saliklis. “Finite element corroboration of buckling phenomena observed in
corrugated boxes”. Wood and Fiber Science, 35(3), 2003.
20. Q.S. Xia, M.C. Boyce, D.M. Parks. “A Constitutive Model for the Anisotropic Elastic-Plastic
Deformation of Paper and Paperboard”. Int. Journal of Solids and Structures, 39, 2002.
7. Acknowledgments
This paper presents results from a research programme carried out with the support from SAICA.
The authors thank specially to the personnel of the Research and Development Laboratory of
SAICA for their invaluable contributions in the preparation and experimental characterisation of
paper, corrugated board and packages, as well as in all the practical aspects related to corrugated
board processing and package converting.
2009 SIMULIA Customer Conference 15
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