Week 8 - Universal Joint

Aim-

      For this project, we will have to perform a transient structural analysis on a double universal joint with a spring using three different materials: Structural Steel, Stainless Steel and Titanium alloy(They can all be found in the General Materials section) The three materials must be used on the joint with the springs alone. To use a refined mesh if possible for the academic license. You need to obtain the Equivalent stress and total deformation for all the three cases and compare them.

Procedure-

• We have to first start as new project in the ansys workbench Select transient Structural and select the proper material for the cam.
• Here material has been specified in the project so we will select the material according to cases.

Case-1-Structural Steel

Case-2-Stainless Steel

Case-3-Titanium Alloy

• Now we have to import the model for that right click on the geometry tab and hit import>>then select the file from saved location and hit ok.

• Now as per case we have to select the materials as mentioned in question.

Contacts-

Case-1

• Now go to contacts from drop down arrow of connections and right click delete the all contacts, Since we have to go for frictionless contact so we delete all contacts prosent earlier.
• Here we will give joint connections, as follows.
• Fixed joint to Spring Joint body to ground.

• Now Revolute Joint for Gear Joint Body to ground.

• Now Revolute Joint for Spring Joint Body to ground.

• Now Revolute Joint for Ball_1, Gear Joint & Coupling Body to body.

• Now Revolute Joint for Ball_2, Spring Joint & Coupling Body to body.

Mesh-

• We have to keep global mesh size as 3mm.
• Also in mesh in sizing put select adaptive sizing as No & quality>>Smoothing>>medium.

Analysis Setting-

• Here we will run stimulation for 5 time steps, refer below setting for all steps.

• Now we have to define a joint load rotation for geared joint select revolute-ground to gear joint.

Solution Setting-

• Now for stress right click on the solution>>insert>>stresses>>equivalent (von-Mises).
• Here we have to define directional deformation, to do so right click solution>>insert>>deformation>>Total.

Results-

Equivalent Stress-

Case-1

Case-2

Case-3

Total Deformation-

Case-1

Case-2

Case-3

Result Comparision-

• From above result we can say that Max stress obesrved at last time step i.e. at 150deg. and due to spring tension it is observed that max. value occurs at spring only and max in case-1 i.e. in structural steel.
• Total deformation is same for all the above cases but observed near gear joint and least at spring joint because we have fixed the spring of spring joint.

Aminated Results-

Case-1

Equivalent stress-

Total Deformation-

Case-2

Equivalent stress-

Total Deformation-

Case-3

Equivalent stress-

Total Deformation-

Conclusion-

• From above analysis result we can say that the max. stress generated in structural steel and least in titanium alloy.
• Since due to high generated stress values and low yield strength values structural steel and stainless steel will under go plastic deformation.
• But in case of titanium alloy stress value is below yield strength value so it will be below yielding region and regain its original shape after load removal.
• Also density wise we check it is lesser in weight, so joint assembly will be light and more flexible compared to other two.
• So we can say that titanium alloy is best suited material here for joint to work effiently with greater life.
• But cost wise it might not be advisable in some cases.