In the case of a post-critical failure, a substantial change in the geometry of a structure occurs. After reaching the instability of the equilibrium, a stable, strong position is reached again. The post-critical analysis requires an experimental approach. It is necessary to manually load the structure in increments step by step.
In the following, the punch-through problem is shown. The structural component can be thought of as a flat roof that is subjected to pressure from the outside. If the pressure is increased slowly, it first appears that the load is absorbed by a compressive stress and transferred to the support.
For a certain size of the compression load, the system becomes unstable, there is a breakdown.
Then, the load can be increased again, which is then absorbed mainly by tension in the component.
The second-order analysis can basically not cover the punch-through problem due to the linearization of the description of the deformation geometry.
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Structural engineering software for finite element analysis (FEA) of planar and spatial structural systems consisting of plates, walls, shells, members (beams), solids and contact elements