OS-E: 0155 Snap-Fit Analysis (CONSLI versus FINITE)

Snap-fit is a combination of two components namely mating and base part which form a mechanical attachment between them by means of locators, locks and enhancements. Nonlinear Static Analysis with large displacement theory is used to solve this example.

This model can be run with finite sliding and then compared with continuous sliding.

Model Files

Refer to Access the Model Files to download the required model file(s).

The model file used in this example includes:

snap-fit.fem

Model Description

Constrained in all degrees of freedom, the mating part is given. Imposed displacement along the assembly direction and contact is defined between mating and the base part. Also, SPCF forces are requested for calculating the applied load for the imposed displacement.

FE Model
Element Types: CTETRA; RBE2

The linear material properties are:

MAT1 and MATS1
Young’s Modulus: 2700 MPA
Poisson's Ratio: 0.35
Initial Density: 1.04E-9 Mg/mm³

Stress versus Strain curve is defined with MATS1.

Results

Concludes that the high stress concentration areas (Figure 2) are sensitive to the ramp-angle of the block, thickness of the flap and sharp corners. Such problem areas can be improved by means of notches, appropriate angles on the mating and base parts, respectively.

The continuous sliding is smoother comparative to finite sliding (Figure 3).