OBJECTIVE:

1.   To mesh the buckle clip model in such a way that the overall number of elements is less than 31,000. It is mandatory to bring it under 31K.

2.     Simulate the component for both kinds of motion

• Moving the buckle by keeping the clip fixed
• Moving the clip by keeping the buckle fixed.

3.     If one of the motion is not converging, explain why that particular motion when simulated did not converge.

Results and Deliverables 

• Stress generated at the base of the clip
• Contact pressure generated between the outer clip surface and buckle surface
• Total deformation of the clip

SOLUTION:

Step 1: Part Model and Material

The buckle clip model provided was modified with a number of faces being merged so as to analyse the model in the academic version. The material for both bodies in the model was assigned as POM, the material properties are as follows:

Step 2: Connections

The contacts between the bodies were defined, shown in the figure, as frictional contacts with coefficient of friction of 0.15. The behaviour was defined as augmented lagrange, with normal stiffness factor of 0.1 and interface treatment as adjust to offset & ramped effects.

Step 3: Meshing

The meshing was carried out with error limits as standard mechanical. The number of elements and nodes generated were 11670 and 22429 respectively.

Step 4: Analysis settings

The analysis is carried out over 4 steps, weak springs as program controlled, large deflection turned on and all output conditions was set to yes condition. In case2, the buckle was fixed by giving fixed support condition to one of the faces and displacement condition was given to the clip body. In case 1, the conditions were given vice versa such that the clip remains stationary and buckle displaces.