Week 8 - Universal Joint

AIM:

To perform a transient structural analysis on a double universal joint with a spring

OBJECTIVE:

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 and then obtain the Equivalent stress and total deformation for all the three cases and compare them

PROCEDURE:

. Select Transient Structural, drag and drop into Project Schematic.
. Structural Steel, Stainless steel and Titanium alloy are chosen under Engineering Data.
. Change the material type of the joint with spring.
. Case 1: Joint with spring is of Structural Steel.
. Case 2: Joint with spring is of Stainless Steel.
. Case 3: Joint with spring is of Titanium alloy.
. Under geometry tab, import the given geometry, double-click to open Space Claim to register and then update the model.
. A fixed joint was assigned to the end of the spring.
. A revolute joint (body-ground) was given to either ends of the universal joints.
. Revolute joints (body-body) were given to all the pin-to-joint interfaces.
. The mesh size was set to 1.5mm after adaptive sizing was switched off.
. Under transient structural tab, we set the analysis to 5 steps with timestep defined by time.
. A joint load is given to the revolute joint, with rotation in increments of 30deg.
. Equivalent Strain, total deformation and Equivalent Stress plots are requested from the solver as outputs.
. Run the simulation by clicking on SOLVE.

CONDITIONS:

JOINTS



MESH



JOINT ROTATION



CASE 1:

EQUIVALENT STRESS



TOTAL DEFORMATION



EQUIVALENT ELASTIC STRAIN



CASE 2:

EQUIVALENT STRESS



TOTAL DEFORMATION



EQUIVALENT ELASTIC STRAIN



CASE 3:

EQUIVALENT STRES



TOTAL DEFORMATION



EQUIVALENT ELASTIC STRAIN

RESULTS AND CONCLUSION:

Case	Material of joint w/ spring	Eq. Stress (MPa)	Tot. Deformation (mm)	Eq. Strain
1	Structural Steel	1518.2	38.637	0.0076597
2	Stainless Steel	1475.4	38.637	0.0077151
3	Titanium alloy	761.84	38.637	0.0080196

We can observe that the stress is maximum for case 1 where the joint with spring is made of structural steel and is the least in case 3 where it is made of titanium alloy.Total deformation is same for all the materials.Stainless and Structural steel will fail as the stress undergone is much greater than their tensile ultimate strength. Also ,the strain is maximum in case of titanium alloy.