Examine the results of the composite tube problem.
The plot below shows the displacement of the nodes located on the outer radius of the top surface of the tube for cases when pre-failure is turned off and when it is turned on. The displacement of the model run without pre-failure is linear up to a displacement of 0.0016 m, at which point matrix constituent failure occurs throughout the model. With pre-failure on, the displacement is linear up to a displacement of 0.00072 m, then diverges from the pre-failure off results as a consequence of the three discrete reductions in shear stiffness that occur prior to matrix failure. Note the significant difference in displacements at failure between the two curves. With pre-fail off the displacement is 0.0016 m and with pre-fail on the displacement is 0.0051 m.