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.Figure 1. FE Model
Model Files
Before you begin, copy the file(s) used in this example to
your working directory.
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
Figure 2. Element Stress Contour
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).Figure 3. Finite Sliding versus Continuous Sliding