4.10.6 3DNLG-6: Buckling of a flat plate when subjected to in-plane shear

Product: ABAQUS/Standard  

Elements tested

S3    S3R    S4    S4R    S4R5    S8R    S8R5    S9R5   

STRI3    STRI65   

SC6R    SC8R   

Problem description

Material:

Young's modulus = 6.4 × 106, Poisson's ratio = 0.3.

Boundary conditions:

along all edges. at center node.

Loading:

Uniform shear load around edges. The RIKS algorithm is used to increment the shear load to a maximum of 2.12 × 108 per edge.

Initial imperfection:

The midsurface position of the plate is defined by

where , = 1.0, = 0.2897, = –0.0706, = –0.0691, = 0.0384, and = 0.0032.

Reference solution

This is a test recommended by the National Agency for Finite Element Methods and Standards (U.K.): Test 3DNLG-6 from NAFEMS Publication R0024 “A Review of Benchmark Problems for Geometric Non-linear Behaviour of 3-D Beams and Shells (SUMMARY).”

The published results of this problem were obtained with ABAQUS. Thus, a comparison of ABAQUS and NAFEMS results is not an independent verification of ABAQUS. The NAFEMS study includes results from other sources for comparison that may provide a basis for verification of this problem.

Results and discussion

Very similar load-deflection curves are obtained for all the test cases. The SC6R model shows a slightly stiffer response than the other elements. The response of all elements tested is shown below.

Input files

n3g6xf3x.inp

S3/S3R elements.

n3g6xe4x.inp

S4 elements.

n3g6xf4x.inp

S4R elements.

n3g6x54x.inp

S4R5 elements.

n3g6x68x.inp

S8R elements.

n3g6x58x.inp

S8R5 elements.

n3g6x59x.inp

S9R5 elements.

n3g6x63x.inp

STRI3 elements.

n3g6x56x.inp

STRI65 elements.

nlg6_std_sc6r.inp

SC6R elements.

nlg6_std_sc8r.inp

SC8R elements.