45671574-design-validation-of-eot-crane.pdf

DESIGN VALIDATION OF
450 T EOT CRANE WITH
FEA APPROACH

GUIDE TEACHER -
MR.R.N.CHOVATIA
HOD MECHANICAL -
MR.Y.B.CHAUHAN

WHY WE SELECTED THIS TOPIC?
WE ALL ARE INTERESTED IN
DESIGNING FIELD.
SOFTWARE BASED MODELLING AND
ANALYSIS IS AN ADVANCED WAY FOR
HUGE MANUFACTURING UNITS.
CRANE IS WIDELY USED IN INDUSTRY.

INTRODUCTION TO CRANE
A crane is a lifting machine generally equipped with a winder (also
called as wire rope drum), wire ropes or chains and sheaves that can
be used both to lift and lower materials and to move them
horizontally.
It uses one or more simple machines to create mechanical advantage
and thus move loads beyond the normal capacity of a human.
It is a specially designed structure equipped with mechanical means
for moving a load by raising or lowering by electrical or manual
operation.
Cranes can range in capacity from a few hundred pounds to several
hundred tons

TYPES OF CRANE
Cranes are classified into
two major types namely-
MOBILE
FIXED

MOBILE TYPE CRANE
Truck mounted crane
Side lift crane
Railroad crane
Crawler crane
Floating crane
Aerial crane

FIXED TYPE CRANE
Tower crane
Self-erecting crane
Telescopic crane
Gantry crane
OVERHEAD CRANE
Deck crane
Jib crane
Bulk-handling crane
Loader crane

EOT CRANE TYPES
Among various crane types, ELECTRICAL OVERHEAD
TRAVELLING (EOT) cranes are most widely used.
There are mainly two types of EOT crane namely-
SINGLE GIRDER
DOUBLE GIRDER

SINGLE GIRDER
It consists of one girder.
It is used for light duty loads.
The trolley in this type of crane is located below the
girder.

DOUBLE GIRDER
It consists of two girders.
It is used for heavy duty loads in industry.
The trolley in this type of crane located above the girder.

APPLICATIONS
Mechanical industries for steel stock holding.
For lifting structures steels in construction sites.
Used in glass handling.
Railway workshops.
Boat manufacturing industries.
Container lifting.

I.S.STANDARDS
A standard is defined as a document, established and
approved by recognized body that provides for common
and repeated use, rules, guidelines for activities or their
results, aimed at the achievement of optimum degree of
order in given context.
In designing our crane, we have considered the following
standards –

MOTOR
DESIGN OF EOT
DESIGN OF CRANE
DIAPHRAGM
PLATES OF GIRDER
LIFTING HOOKS
PLATES OF END
CARRIAGE
IS 325:1978
IS 3177:1977
IS 807:2006
IS 3815
IS 2062
IS 2062
IS 2062

LOAD CONSIDERATIONS &
CALCULATIONS
We are calculating a load based on IS 807:2006.
The three different cases of loading are to be considered:
1.Working without wind.
2.Working with limiting working wind.
3.For exceptional loadings.
In our case it is the case of crane working
without wind as the crane is of indoor type.

CALCULATION FOR CRANES WORKING WITHOUT WIND
(Static load due to dead weight) + (working load) ×
(dynamic coefficient, Ψ)
IMPACT FACTORS (Ψ)
The impact loads caused in the hoisting operation are
different in value according to the hoisting speed,
deflection of the girder, rope length, and are given by
multiplying the impact factor.
As our crane is a M5 type, the value of impact factor is
1.32.
WORKING LOAD IS 450 TONS

DUTY FACTOR
The value of duty factor depends upon the group
classification of the cranes. The main loads shall be
multiplied by the duty factors considering the working
conditions and importance of the duty.
As our crane is a M5 type, the value of duty factor is
1.06.

PRINCIPAL LOADS EXERTED ON THE STRUCTURE
Total weight of crane = (weight of main girder × 2) +
(weight of end carriage assembly × 2) + bottom pulley
block assembly + crab = 276 tons.
Total weight of main girder = 36.782 tons.
Total weight of end carriage assembly = 36.628 tons.
Total weight of bottom pulley block assembly = 16.95
tons.
Total weight of crab = 110 tons.

ALLOWABLE STRESS
In our crane for mild steel as per IS 2062, the maximum
permissible stress is 250 Mpa.
The factor of safety is 1.4.
The allowable safe stress is =
= 178.57 Mpa

LIMITING DEFLECTION OF GIRDER
The maximum vertical deflection of the girder produced
by the dead load, weight of the trolley and rated load shall
not exceed 1/750 of the span of the crane for more than 12
meters.
The span of the crane is 27200 mm.
So maximum vertical deflection= span × (1/750)
= 27200 × (1/750)
= 36.27 mm.

HOISTS AND DESCRIPTION
HOIST : It is a load lifting device which consists of
motors, wire ropes, hook, etc.
 Hoists are of two main types namely
Chain hoist or chain block
The wire rope or cable type.
In our case we have selected wire-rope type hoist.

As per load lifting capacity we can divide hoist in two
types:
1.Main hoist.
2.Auxiliary hoist
Main Hoist: It is primary hoist mechanism provided for
lifting and lowering the rated load the crane.
Auxiliary Hoist: It is a supplemental hoisting unit used to
handle light load.
We are using three phase induction motor.

INTRODUCTION TO CAD
Computer-aided design (CAD) is the use
of computer technology for the design of objects, real or
virtual.
Current Computer-Aided Design software packages range
from 2D vector -based drafting systems to 3D solid and
surface modelers.
Modern CAD packages can also frequently allow
rotations in three dimensions, allowing viewing of a
designed object from any desired angle, even from the
inside looking out.

CAD is mainly used for detailed engineering of 3D
models and/or 2D drawings of physical components.
There are many software’s for CAD namely PRO-
ENGINEER, CATIA, SOLIDEDGE, SOLIDWORKS,
UNIGRAPHICS etc.
Amongst all these cad software’s we have selected PRO-
ENGINEER, developed by Parametric Technology
Corporation, which is one of the world’s fastest growing
solid modeling software.

INTRODUCTION TO PRO-E
Pro/ENGINEER is a parametric, integrated
3D CAD/CAM/CAE solution created by Parametric
Technology Corporation (PTC).
Pro/ENGINEER is the first to market with parametric, feature-
based, associative solid modeling software in the market and is
a very user-friendly tool.
This solid modeling tool allows us to easily import the
standard format files.
The bidirectional associative nature of this software ensures
that any modification in the model is automatically reflected in
the drawing views.

3D DEVELOPMENT IN PRO-E WILDFIRE 4.0
The main assemblies created in Pro/ENGINEER are listed
below-
1.MAIN GIRDER
2.END CARRIAGE ASSEMBLY
3.BOTTOM PULLEY BLOCK ASSEMBLY
4.RAMSHORN HOOK

MAIN GIRDER ASSEMBLY
 The main girder shall extend over the whole width of the end carriage and the
extension shall have sufficient section on to take the maximum reaction and moment.
 In the main bridge girders, in addition to the required full length diaphragms, short
diaphragms should be inserted whenever required to transmit the trolley wheel load to
the web plates and to limit the maximum stress in the trolley rail within permissible
limits. All diaphragms must bear against the top flange.

INTERNAL CONSTRUCTION OF GIRDER
Diaphragm is a vertical plate between the girder plates
which serves to support the top cover plate and to transfer
the forces of the trolley wheel load to the webs rails.

END CARRIAGE ASSEMBLY
 END CARRIAGE ASSEMBLY IS A MECHANICAL STRUCTURE WHICH
PROVIDES SUPPORT TO THE MAIN GIRDERS.
 IT ALSO PROVIDES LONGITUDINAL MOTION TO THE MAIN GIRDERS.

SUB ASSEMBLIES OF END CARRIAGE
ASSEMBLY:-
1.End carriage
2.Connecting link
3.Balancer body
4.Axle box

CONNECTING LINK OF THE ASSEMBLY

BALANCER BODY OF THE ASSEMBLY
AXLE BOX

SUB ASSEMBLIES OF BOTTOM PULLEY BLOCK
ASSEMBLY:-
1.Side plate
2.Middle cover
3.Side cover
4.Crosshead

CROSSHEAD
SIDE COVER
MIDDLE COVER
SIDE PLATE

HOOK
•A lifting hook is a device for grabbing and lifting loads by means of a device
such as a hoist or crane. Lifting hooks are usually equipped with a safety latch to
prevent the disengagement of the lifting wire rope sling, chain or rope to which
the load is attached.
•Standard shank Ramshorn hook for the Main Hoist and shank type plain hook
for Auxiliary Hoist should be used.

INTRODUCTION
Finite element analysis (FEA) has become
commonplace in recent years. Numerical
solutions to even very complicated stress
problems can now be obtained routinely using
FEA.

Finite Element Analysis (FEA) is a mathematical
representation of a physical system comprising a
part/assembly (model), material properties and applicable
boundary conditions (collectively referred to as pre-
processing), the solution of that mathematical
representation (solving), and the study of results of that
solution (post-processing).
Simple shapes and simple problems can be done by hand
but most real world parts or assemblies can’t be done
accurately and quickly without computer and appropriate
analysis software.

THREE PRINCIPAL STEPS IN FEA
A finite element analysis usually consists of three
principal steps:
1.Pre-processing.
2.Analysis.
3.Post-processing.

PRE-PROCESSING
To do this, FEA software typically uses a CAD
representation of the physical model and breaks it down into
small pieces called finite “elements”. This process is called
“meshing.” The higher the quality of the mesh (collection of
elements), the better the mathematical representation of the
physical model.
The primary purpose of an element is to connect nodes with
predictable mathematical equations based on stiffness
between nodes; the type of element used often depends upon
the problem to be solved. The behaviour of each element, by
itself, is very well understood.

There are many different types and classes of elements,
most created for specialized purposes.
A one-dimensional element represents line shapes, such
as beams or springs. A 2D element, also known as a
quadrilateral element, will represent triangles and squares.
3D elements represent solid shapes and are usually in 2
basic shapes: brick (hexahedrons or “hex”) and pyramids
(tetrahedrons or “tets”).

ANALYSIS
The dataset prepared by the preprocessor is used as input
to the finite element code itself, which constructs and
solves a system of linear or nonlinear algebraic equations.
In addition to linear/static, ANSYS Workbench performs
Coupled analysis types (thermal-stress, stress-modal,
thermal-stress model) as well as some limited non-linear
analysis types (thermal with temperature-dependent
material properties and convection, geometric/contact
with contact supporting lift-off).

POST-PROCESSING
Typical postprocessor display overlays colored contours
representing stress levels on the model, showing a full-
filled picture similar to that of photo elastic or more
experimental results.
In the simple terms, Post-processing is used to create
graphical displays that show the distribution of stresses,
strains, deformations, temperatures, and other aspects of
the model.

Interpretation of these post-processed results is the key to
identifying weak areas in a model, areas of material waste,
or valuable information on other model performance
characteristics (thermal, modal) that otherwise would not
be known until a physical model were built and tested.

LIST OF ANALYSIS SOFTWARE
ABAQUS
ADAMS
ADINA
ANSYS
C-Mold
DIANA
Fast 3D
INERTIA
LS-DYNA3D
MARC
MSC/NASTRAN
NISA
OptiStruct
PERMAS
STRAND
UAI

WHY ANSYS?
In our project we have selected ANSYS software for
FEA analysis because it is very user friendly, has
better material library and also gives appropriate
results in comparison with others software’s available
in the market.

TYPES OF ANALYSIS
STRUCTURAL ANALYSIS
STATIC ANALYSIS
FATIGUE ANALYSIS
HEAT TRANSFER ANALYSIS
SHAPE OPTIMIZATION
VIBRATIONAL ANALYSIS
HARMONIC ANALYSIS

TYPES OF ANALYSIS CONSIDERED FOR EOT
STRUCTURAL PARTS
There are several types of analysis like static structural
analysis, flexible dynamic analysis, rigid dynamic
analysis, harmonic response analysis, model analysis,
linear buckling analysis, random vibration analysis etc.
Here we have considered static structural analysis for
450 ton EOT crane.
By selecting this analysis option in ANSYS workbench
11.0 we can get displacement, stresses, strain and forces in
structures caused by loads.

STEPS FOR FEA IN ANSYS
WORKBENCH 11.0
A finite element analysis usually consists of three
principal steps:
1.Pre-processing.
2.Analysis.
3.Post-processing.
Now we are going to see the analysis of major assemblies
of the crane.

LOAD CASE IDENTIFICATION
Load case 1: Crab at the centre of the span

Load case 2: Crab at the either of the end sides of the span

LOADS COMING ON MAIN GIRDER
Following loads are considered in the finite element
analysis of the structure assembly:
Self weight of the structural parts.
Horizontal forces acting on structure due to motion of the
crane.
Weight of crab assembly.
Vertical forces due to externally lifted load.
To account for the effect of hoisting motion, duty and
service conditions and acceleration and deceleration while
travelling, the concerned loads are multiplied by impact
factor, duty factor as per IS:807-2006.

VERTICAL FORCES DUE TO LIFTED LOADS
For a class II M5 crane,
load in a vertical direction = impact factor × lifted load
= 1.32 × 450
= 594 T
Total load acting vertically downward,
= (Duty factor × Load in vertical direction) + weight of crab
assembly
= (1.06 × 594) + 110
= 739.64 T

HORIZONTAL FORCES DUE TO
LONGITUDINAL TRAVEL OF STRUCTURE
For a class II M5 crane, the horizontal forces due to crane
travel in longitudinal direction are given as,
Force value = 0.0632 × (Lifted load + Total weight
of crane)
= 0.0632 × (450 + 276)
= 45.88 T
Considering the effect of Duty factor,
Total force = 1.06 × 45.88
= 48.63 T.

PRE-PROCESSING
•Here, we have selected hex dominant method for meshing of main
girder having a size of 25mm.
•After applying the element size, we get 11,76,296 nodes.

SOLVING
•Force and displacement are given in this step.
DISPLACEMENT

Self weight of girderE
Horizontal force applied as
acceleration acting on girder

LOAD CONDITION FOR CASE 1
Direction
Applied load at the centre
of girder
DOF
-Y axis
3.623962e+006N
Zero

Direction
Applied load at the centre
of girder
DOF
-Y axis
3.623962e+006N
Zero

POST-PROCESSING
Stress and deformation produced due to the applied load
can be calculated in this step.
We have selected here two results : Von-Mises stresses
: Total deformation
The results obtained from above considerations are
shown in figure.

Total deformation for girder case 1

Equivalent stress for girder case 1

Total deformation for girder case 2

Equivalent stress for girder case 2

GIRDER
From equivalent stress result of FEA in ANSYS Workbench 11.0 of MAIN
GIRDER, it is found that maximum stress occurred is 383.41 Mpa in case 1
and is 490.24 Mpa for case 2 which is at the edge of the fixed plate. So it is
negligible.
Now the average stress on whole girder is 156.28 MPa which is less than
allowable stress(178.57 Mpa) of mild steel.
The total deflection is 24.463 mm for case 1 and 9.778 mm for case 2
which is less than 36.26 mm.
Therefore we can say that the design of girder is safe.

LOAD CASE IDENTIFICATION
Load case 1 : Load applied on horn

Load case 2 : Load applied on hole

LOAD COMING ON HOOK
Following loads are considered in the FEA of the
hook:
Load in vertical direction = Impact factor × Duty
factor × Lifted load
= 1.32 × 1.06 × 450
= 629.64 T

PRE-PROCESSING
• Here, we have selected hex dominant method for meshing of main girder
having a size of 20mm.
• After applying the element size, we get 2,63,799 nodes.

-Y axis
6.1705e+006N
Zero
Direction (at centre of the hole)
Applied load
DOF

Direction (at both side horn)
 Applied load
DOF
-Y axis
3.0884e+006N
Zero

POST-PROCESSING
We have selected here two results : Von-Mises stresses
: Total deformation
The results obtained from above considerations are shown
in figure.

Equivalent stresses for hook case 1

Total deformation for hook case 1

Equivalent stresses for hook case 2

Total deformation for hook case 2

HOOK
From equivalent stress result of FEA in ANSYS Workbench 11.0 of
RAMSHORN HOOK, it is found that maximum stress occurred is 575.59
Mpa which is at the edge. So as per geometrical considerations stress on
the edge is negligible.
Now the average stress of the hook is 127.91 Mpa which is less than
allowable stress of mild steel.
Therefore we can say that the design of hook is almost safe.
From the results of case 1 & 2 we can say that load case 1 is better than
case 2, because deformation is less in case 1 as compared to case 2.

LOAD COMING ON BPBA
Following loads are considered in the FEA of the bottom
pulley block assembly:
Load in vertical direction = Impact factor × Duty
factor × Lifted load
= 1.32 × 1.06 × 450
= 629.64 T

PRE-PROCESSING
•Here, we have selected hex dominant method for meshing of main girder having a
size of 30mm.
•After applying the element size, we get 5,51,131 nodes.

SOLVING
Displacement and load case

-Y axis
6.1705e+006N
Zero
Direction
Applied load
DOF

BOTTOM PULLEY BLOCK ASSEMBLY
From equivalent stress result of FEA in ANSYS Workbench 11.0 of
BOTTOM PULLEY BLOCK ASSEMBLY, it is found that maximum
stress occurred is 123.7 Mpa which is less than allowable stress of mild
steel.
Therefore the design of BOTTOM PULLEY BLOCK ASSEMBLY is safe.
From the analysis we observe that value of stress at the side covers and
middle covers is very small and stress on the crosshead is maximum. So
we can remove material from the side and middle covers.
For reducing stress concentration at the crosshead we can add material
to it.

PRE - PROCESSING
hex dominant method is selected for meshing of end carriage assembly
having a size 25 mm.
After applying the element size, we get 8,35,467 nodes.

SOLVING
Displacement and load case
The Axle Mounting Points on Balancer Body are fixed and
both the pin are given revolute joint as shown in figure.

Direction
Applied load at centre of both end
carriage
DOF
LOAD CONDITION
-Y axis
31,47,766.438 N
Zero

Self weight of End
carriage assembly
Horizontal force applied as acceleration acting on end carriage assembly

POST-PROCESSING
We have selected here two results: Von-Mises stresses
: Total deformation
The results obtained from above considerations are shown
in figure.

BIBLIOGRAPHY
(INDIAN STANDARD) DESIGN, ERECTION AND
TESTING (STRUCTURAL PORTION) OF CRANES
AND HOISTS – CODE OF PRACTICE (Second
Revision - 2006)
Pro/ENGINEER Wildfire 4.0 (for engineers and
designers) by Prof. Sham Tickoo
ANSYS 11.0 by SmardCAD India Pvt Ltd.
www.scribd.com/search?
cat=design&q=crane&sa.x=39&sa.y=24
www.pdfdatabase.com/eotcrane-pdf.html

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