VM189

VM189
Stress Relaxation of a Chloroprene Rubber

Overview

Reference:

Dal, H. et al. "Bergstrom-Boyce model for nonlinear finite rubber viscoelasticity : theoretical aspects and algorithmic treatment for the FE method”. Computational Mechanics. 2009, 44: 809-823

Analysis Type(s): Static (ANTYPE = 0)
Element Type(s):

3D Structural Solid Elements (SOLID185)

Input Listing: vm189.dat

Test Case

A uniaxial compression test with intermittent relaxation time is performed on a block modeled with Chloroprene rubber. The block is subjected to true strain rates of and with 120s relaxation time at and , respectively. Figure 291: Time History of Displacement Loadings shows the loading history. The true stress computed for load steps 1,3,5,6 and 8 are compared against the reference solution.

Figure 290: Uniaxial Loading Problem Sketch

Uniaxial Loading Problem Sketch

Figure 291: Time History of Displacement Loadings

Time History of Displacement Loadings

Material PropertiesGeometric PropertiesLoading

Parameters for Bergstrom-Boyce model:

μ0=0.60 MPa

N0=8

μ1=0.96MPa

N1=8

c=-1

m=4

W=1mm

  1. Compressed 0.26mm within 100s

  2. Relaxation 120s

  3. Compressed to 0.45mm within 100s

  4. Relaxation 120s

  5. Compressed to 0.55mm within 100s

  6. Returns to displacement -0.45mm within 100s

  7. Relaxation 120s

  8. Returns to displacement -0.26mm within 100s

  9. Relaxation 120s

  10. Returns to initial state within 100s

Analysis Assumptions and Modeling Notes

The problem is solved using 3D SOLID185 elements. The Bergstrom-Boyce material is defined by TB,BB. The block is subjected to one cycle of uniaxial compression testing with intermittent relaxation time. The stress for load steps 1,3,5,6 and 8 are acquired using *GET in /POST1.

Results Comparison

Mechanical APDLTargetRatio
Set 1-0.638 MPa-0.650 MPa0.981
Set 3-1.191 MPa-1.160 MPa1.026
Set 5-1.583 MPa-1.580 MPa1.002
Set 6 -0.859 MPa-0.840 MPa1.022
Set8-0.392 MPa-0.400 MPa0.981