1. Points Discussed in RPS 1
Literature Survey
Connections shortlisted for study
Cyclic loading protocols and its details
Intro to ABAQUS
Finite element mesh sensitivity analysis and optimization for
connection geometry
Software verification is done by comparing standard moment
connection cyclic loading data with abacus data
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2. Conclusive points of RPS 1
Pre Qualified welded connections can be used for further study
Sufficient research literature is available
Mesh sensitivity analysis shows that 20mm element size is sufficient
SAC protocol loading can be used to study the cyclic behavior of steel
connections
Nonlinear hysteretic behavior of steel connection achieved in
ABAQUS is well matched with tested data of the connection.
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3. Points Discussed in RPS 2
Stress concentration problem identified in steel connections and
literature reviewed
Pre-qualified connections designed as per AISC and IS code guidelines
FEM modeling done in ABAQUS
Load vs Displacement behavior
Maximum von mises stress vs load behavior
Stress concentration factor vs load behavior
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4. Conclusive points of RPS 2
Parallel sections can satisfy all the design requirement
SCF factor in haunch connection is lowest
Stiffness of haunch connection is highest
High plastic strain in web region of column so diagonal stiffener of
doubler plate is required
SCF factor stay linear in elastic stage and decreases as in the plastic
stage
Reinforcements in connections like column web stiffener plats and
brackets reduces SCF
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6. RPS 3 Points
A) Parametric study of type 1 connection for SCF
Sectional properties as per IS code
Applied loading as per beam design
Connection matrix
Connection design check for reinforcements
Considered non dimensional factors for parametric study
ABAQUS modeling and results
Linear regression equation development and check
Conclusions
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7. RPS 3 Points
B) Parametric study of type 1 connection for SCF
Specimens for cyclic behavior
Applied SAC loading protocol
Nonlinear cyclic behavior analysis results of ABAQUS
Conclusions
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8. SCF factor
• When an engineering component is being subjected to fluctuation loads, its
life is adversely affected because premature failure takes place through the
surface
• Fatigue is a phenomenon featured by the decay of the member’s strength
progressively leads to the appearance of cracks and eventually sudden and
catastrophic failure of the member
• Many factors control fatigue life of welded joints. Joint type, joint loading and
detailing of the joint are among the most critical factors that must be
considered. The type of the loading depends mainly on the type of the
structure.
• The localized peak stresses are defined as the nominal stresses multiplied by
stress concentration factor (SCF).
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9. • Hot spot stresses are usually defined as the maximum or peak
geometric stresses that occur where cracks would initially be
nucleated
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10. 1.5 Nominal stresses
• The nominal stresses are the maximum stresses that develop in the member
when being subjected to forces.
• Theses stresses are based on the elastic behavior of the member and derived
from the basic beam theory. Due to weld components, stress raisers are not
considered in normal stress calculation, Determining the nominal stresses is
a straightforward task.
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12. Study of building under EQ loading and member selections
For the selection of section for the research study the real geometrical
building with real earthquake loading has been selected and has been
designed according to IS 800 : 2007
Building is designed in STAAD Pro.
The bottom part of building at plinth and below plinth is of RCC
Clear height of building is 4m
One direction the moment frame and in another direction the braced frame
with shear connections has been designed.
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14. Loading consideration
• Earthquake loading has been considered as per IS 1893 : 2016 part 1.
• The building is considered in zone 3 type with damping of 2%.
• Z = 0.16, R = 4 as per IS 1893:2005 part 4, I = 1
• Dead load of 150mm thick slab and outer peripheral brick wall load has been
considered.
• Live load of 4 kN / m2 considered for medium industrial usages as per IS 872
part 2
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16. Sectional properties
• All main beams were assigned with IPE300 / NPB300 as per
IS 22778:2004 code for parallel beam sections.
• All secondary beams were assigned with NPB 140
• All columns are provided with HE200A
• Fy = 250 Mpa with Fu = 420 Mpa material properties has been
considered in the design
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18. Design output
and Unity check
• Load case 1.3 DL + 1.3 LL –
1.3 EQX is governing in the
design.
• So max end moment and
shear for which the connection
should be designed is as
follows
• Mu = 80 kN.m and Vu = 84.01
kN
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19. Connection design
• Type 1 & Type 2 Connection design
• For bending A = 2 * 150 mm (width of beam flange) = 300 mm2
• Ixx = 2 x 150 x (150)^2 = 6.75 x 10^6 mm4
• Z = Ixx / Y = (6.75 x 10^6) / 150 = 45 x 10^3
• Normal stress = 4 kN / 300 mm = 0.013 kN / mm
• Bending stress = (80 x 10^3) / (45 x 10^3) = 1.77 kN / m
• Vector sum of both stresses = 1.77 kN / m
• Weld Size = (1.77 x 10^3) / (510 x (1.73 x 1.25)) = 7.514 < 10.7 (flange thickness of IPE300 beam)
• So full flange will be grove weld with may welding access hole may be provided.
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20. • For Shear
• Dimension available = 300 – 10.7 x 2 -15 = 263.6 let’s 200 mm
• Weld size = 84 x 10^3 / (0.7 x 2 x 260 x (510 / (1.73 x 1.25)) = 0.979 mm
• So minimum 5mm filet weld size is adopted.
• Column check for stiffeners
Check =0.4 √ (Af / 1.1) = 0.4 x √ ( 150 x 10.7) / 1.1 = 15.27 > 10 mm = tfc
• Hence the column stiffeners is required for sufficient rigidity
• K = tfc + twc = 10 + 6.5 = 16.5
• Local web yielding
• Pbf = Fwc x twc x (5K + tfb) / 1.1
= 250 x 10 x (5 x 16.5 + 10.7) / 1.1
= 211.81 kN
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21. • Kaufmann, E.J., Fisher, J.W., DiJulio, R.M., and Gross, J.L. (1997). "Failure Analysis of Welded Steel Moment Frames Damaged in
the Northridge Earthquake," NIS-TIR 5944, National Institute of Standards and Technol-ogy, Gaithersburg, MD.
• Kaufmann, E.J., Xue, M., Lu, L.W., and Fisher, J.W (1996) "Achieving ductile behavior of moment connections," Modern Steel
Construction, American Institute of Steel Construction, Inc., January 1996.
• Tong, L. W., Zheng, H. Z., Mashiri, F. R. & Zhao, X. L., 2013. Stress concentration factors in circularhollow section and square
hollow section T-connections: Experiments, Finite-Element Analysis,and Formulas'. Journal of Structural Engineering, 139(11),
pp. 1866-1881.
• UEG, 1987. Review of current methods for determining hot-spot stresses and stress concentrationfactors, London, UK: UEG's
Tubular Joint Group.
• Ummenhofer, T. et al., 2011. Extension of the fatigue life of existing and new welded hollow section joints, Germany: CIDECT.
• Van Delft, D. R., Noordhoek, C. & Da Re, M. L., 1987. The results of the European fatigue tests on welded tubular joints
compared with SCF formulas and design lines. Steel in Marine Structures, Elsevier Applied Science Publishers, Ltd., pp. 565-577.
• Van Delft, D. V., Noordhoek, C. & de Back, J., 1985. Evaluation of the European fatigue test data on large sized weld tubular
joints for offshore structures. Houston, USA, Offshore Technology Conference.
• Van Wingerde, A. M., 1992. The fatigue behavior of T- and X-joint made of square hollow sections, The Netherland: Heron.
• Van Wingerde, A. M., Packer, J. A. & Wardenier, J., 1997. IIW fatigue rules for tubular joints. San Francisco, IIW International
Conference on performance of Dynamically Loaded Structures.
• Winkel, G. D., 1998. The static strength of I-beam to circular hollow section column connections, The Netherlands: Delft
University of Technology.
• Yeoh, S. K., Soh, A. K. & Soh, C. K., 1994. Behaviour of tuular T-joint subjected to combined loadings. Journal of Construct. Steel.
• Zhao, X.-L.et al., 2001. Design guide for circular and rectangular hollow section welded joints under fatigue loading. s.l.:CIDECT.
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