Transient Structural Analysis of Slider Crank Mechanism using Ansys

Objective - Simulate the slider crank mechanism for the cases given below.

Case 1 - Run the simulation without contact.

Case 2 - Create contacts between the various slider crank components and assign material properties to the geometry with frictional coefficient as per given below.

Procedure -

Case 1 - Run the simulation without contact.

Create Transient structural analysis and in engineering data select the material structural steel.

Structural Steel.

Import the geometry and check in SpaceClaim for any irregularities.

Then open Ansys mechanical and rename the geometry as Crank, Handle_1, Handle_2 and Fixture then assign the structural steel material.

Joints - Five joints created in whole geometry.

Fixed - Ground To Fixture

Revolute - Ground To Crank

Revolute - Handle_1 To Crank

Translational - Handle_2 To Handle_1

Translational - Fixture To Handle_2

Mesh - Mesh the whole geometry with 10mm element size and set adaptive sizing to no.

Analysis Settings - The simulation runs for 4 steps. So, the number of steps is set as 4.

In the first step large deflection set to on and defined by time. Initial time step set to 0.2s, Minimum time step set to 0.1s and Maximum time step set to 0.3s. In Output control set all output to yes.

The second step to four step large deflection set to on and defined by time. Carry over time set to on, Minimum time step set to 0.1s and Maximum time step set to 0.3s. In Output control set all output to yes.

Joint - Rotation - Crank is provided a rotation of 360 degrees.

Run the simulation and results obtained.

Result - The analysis runs successfully and results obtained.

Total Deformation Max - 4.7834 mm

Equivalent Stress Max - 0.0077579 Mpa

Total Velocity Max - 141.01 mm/s

Animation Equivalent Stress

Case 2 - Create contacts between the various slider crank components and assign material properties to the geometry with frictional coefficient as per given below.

Same as Case 1 but with contact.

Create Transient structural analysis and in engineering data select the material structural steel.

Structural Steel.

Low Carbon Steel.

Gray cast iron

Joints - Same as Case 1

Contact - three contacts created as frictional with coefficients of different friction.

Frictional - Crank To Handle_1 with coefficients of friction of 0.3

Frictional - Handle_1 To Handle_2 with coefficients of friction of 0.23

Frictional - Handle_2 To Fixture with coefficients of friction of 0.15

Mesh - Mesh the whole geometry with 10mm element size and set adaptive sizing to no and for contact face use face sizing option with element size of 5mm.

Same as Case 1

Analysis Settings - The simulation runs for 4 steps. So, the number of steps is set as 4.

In the first step large deflection set to on and defined by time. Initial time step set to 0.2s, Minimum time step set to 0.1s and Maximum time step set to 0.3s. In Output control set all output to yes.

The second step to four step large deflection set to on and defined by time. Carry over time set to on, Minimum time step set to 0.1s and Maximum time step set to 0.3s. In Output control set all output to yes.

Joint - Rotation - Crank is provided a rotation of 360 degrees.

Run the simulation and results obtained.

Result - The analysis runs successfully and results obtained.

Total Deformation Max - 5.6002 mm

Equivalent Stress Max - 165.69 Mpa

Total Velocity Max - 140.8 mm/s

Frictional Stress in Crank To Handle_1 Contact Max - 10.494 Mpa

Frictional Stress in Handle_1 To Handle_2 Contact Max - 8.3405e-5 Mpa

Frictional Stress in Handle_2 To Fixture Contact Max - 3.4246e-7 Mpa

Animation Equivalent Stress

Conclusion -

• Total Deformation is higher in Case 2 With Contact.
• Equivalent Stress is lower in Case 1 Without Contact as there is no friction acting on the contacts and the stress is increased to overcome the friction in Case 2 With Contact.
• Total Velocity is slightly higher in Case 1 Without Contact as there is no friction acting on the contacts.
• Maximum frictional stress is experienced by the rotational joint between Crank To Handle_1.

Google drive link - https://drive.google.com/file/d/1vm4eIV9K2b4E-EF3wi4heMraTKk-whYO/view?usp=sharing