Test 8B: 2D plane stress – uniaxial displacement, primary 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

CPS8R

Problem description



Material:

Young's modulus = 200 × 103 N/mm2, Poisson's ratio = 0.3, Creep law: ε = Aσn⁢tm, A = 3.125 × 10−14 per hour (σ in N/mm2), n = 5, m = 0.5.

Boundary conditions:

ux=0 on line AD, uy=0 at mid-point of line AD and u1=0.1 on line BC.

Reference solution

This is a test recommended by the National Agency for Finite Element Methods and Standards (U.K.): Test 8(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
Time HardeningStrain Hardening
tσx⁢xctσx⁢xc
0.00 200.00 (0.00%) 0.00 200.00 (0.00%)
0.56 95.09 (4.41%) 0.57 99.60 (−4.46%)
6.38 63.78 (0.77%) 6.29 76.80 (−0.71%)
30.96 51.34 (−4.55%) 57.42 60.92 (−1.39%)
235.76 39.42 (−5.78%) 285.71 51.27 (0.49%)
628.98 34.75 (−2.61%) 666.19 46.80 (−1.99%)
1000.00 32.79 (−1.80%) 1000.00 44.91 (−0.92%)



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 = 5. × 10−6.