Test 6B: 3D – triaxial displacement, secondary creep

This problem provides evidence that Abaqus can reproduce the result from the benchmark defined by NAFEMS and cited as the reference solution.

This page discusses:

ProductsAbaqus/Standard

Elements tested

C3D20R

Problem description



Material:

Young's modulus = 200 × 103 N/mm2, Poisson's ratio = 0.3, Creep law: ε = Aσn⁢t, A = 3.125 × 10−14 per hour (σ in N/mm2), n = 5.

Boundary conditions:

ux=0 on face ADEH, uy=0 on face ABFE, uz=0 on face ABCD, ux=0.3 on face BCGF, uy=0.2 on face CDHG, and uz=0.1 on face EFGH.

Reference solution

This is a test recommended by the National Agency for Finite Element Methods and Standards (U.K.): Test 6(b) from NAFEMS Publication Ref: R0027, “NAFEMS Fundamental Tests of Creep Behaviour,” June 1993.

The time marching program provided in Appendix B of the NAFEMS Publication can be used to obtain the stress variation with time.

Results and discussion

The results are shown in the following table. The values enclosed in parentheses are percentage differences with respect to the reference solution.

Abaqus Results
tσx⁢x
0.00 1153.85 (0.00%)
1.00 1046.70 (0.31%)
9.91 1026.80 (0.26%)
77.02 1016.20 (0.18%)
144.13 1013.90 (0.19%)
681.00 1009.40 (0.10%)
1000.00 1008.40 (0.07%)



Remarks

The total creep time for this test is 1000 hours. The times listed in the above table are the times calculated by the Abaqus automatic time stepping algorithm with CETOL = 1. × 10−4.