study of universal joint simulation and calculation of stress and their comparision
OBJECTIVE :- In this challenge the main objevtive is to perform a simulation of double universal joint by alloting different material to a spring attached joint. And also we have to check the deformation and stress values for these three cases and compare them with one another.
SET-UP AND PRE-PROCESSING DONE FOR THE UNIVERSAL JOINT SIMULATION ARE AS FOLLOWS:-
Here the analyisis is performed on transient structural, The geomertry was imported in the geometry section and it was edited in the space claim module, so that it will get the space claim extension. Then the the mechanical module is opened up, for setting up the conditions . All the initial contact regions was deleted which is automatically detected by the software , here we don\'t defined any contacts ,only revolute joints and fixed joint plays very important role in this simulation.
Firstly i defined fixed body-to-ground joint for spring and then the revolute joint for first yoke and second yoke were defined,
The other joint is in between pin and the foremost end for the yoke body, here there are total 8 joints was defined but ,only details of few is illustrated as there defining parameter is similar for the other joints.
meshing configurations:-
Analysis setting are given by two steps, (1) and (2-5)
joint rotation is provided to yoke other than springattached yoke.
in this way the simulation was setup and results are carried out by assigining different material to the spring jointed yoke.
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case 1= material used structural steel
Total Deformation Stress overall Stress development in middle unit.
38.637 mm 1583.3 mpa 6.309 mpa
deformation graph stress graph
case 2= material used stainless steel
Total Deformation Stress overall Stress development in middle unit.
38.637 mm 1534.3 mpa 6.306 mpa
deformation graph stress graph
case 3= material used titanium alloy
Total Deformation Stress overall Stress development in middle unit.
38.637 mm 780.57 mpa 6.26 mpa
deformation graph stress graph
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RESULT ,COMPARISION AND CONCLUSION:-
CASES Total Deformation Stress overall Stress development in middle unit.
1. 38.637 mm 1583.3 mpa 6.309 mpa
2. 38.637 mm 1534.3 mpa 6.306 mpa
3. 38.637 mm 780.57 mpa 6.26 mpa
The results are compared above deformations for all cases are similar , because we provided the displacement (rotation)for the joint and the conections are defined to allow the motion transmit from the hub yoke to spring yokr through middenle unit and two pins, Although the stress development in the middle portion is same as we are not applying any constraints to it it is free to rotated and transmit motion from one driver yoke to driven.
The variations we see in the stress overall, because the materaial is diffrent for all cases ,first and second case having slight diffrence because the yeild strength of structural and stainless steel is some what similar, but we see the large variation in titanium condition as its ultimate and yeild tensile strength is very high as compared to other two materials , so it is having higher resistance to deformation on the externally applied load. the properties are listed below-
so this is only the reason for the high variation of stress in this case.
And the conclusion is that if we use materail with high ultimate tensile or yeild strength then the universal joint design will be more tough, to sustain heavy loading (dynamic condition).
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