4.7.6 Test 5: Axisymmetric crack in a bar

Product: ABAQUS/Standard  

Elements tested

CAX8    CAX8R   

Problem description

Mesh:

Collapsed elements with 1/4 point midside nodes are used at the crack tip. Half of the axisymmetric test geometry is modeled.

Material:

Young's modulus = 207 GPa, Poisson's ratio = 0.3.

Boundary conditions:

along edge AB, along edge AE.

Loading:

Uniform stress, = 100 N/mm2.

Reference solution

This is a test recommended by the National Agency for Finite Element Methods and Standards (U.K.): Test 5 from NAFEMS publication “2D Test Cases in Linear Elastic Fracture Mechanics,” R0020.

Target solution: K/K = 0.475, K =

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.

Element TypeK/K
CAX80.484 (+1.87%)
CAX8R0.485 (+2.06%)

Remarks

K = . An average of the J values calculated by ABAQUS, excluding the first contour, is used in reporting the results. Experience has shown that the crack-tip elements do not give sufficiently accurate results to give good estimates of the J-integral for the first contour.

Input files

nlf5xf8x.inp

CAX8 elements.

nlf5xr8x.inp

CAX8R elements.