This example shows the difference using various integration methods and a different number of integration points on the result. For this purpose, a three-layer, point-supported slab with a length of 5 m and a width of 2 m will be considered. It consists of an orthotropic, plastic material, comparable to cross-laminated timber.
A load of 25 kN is applied to the slab. The target length of the finite elements is 0.1 m, with an additional mesh refinement provided at the nodal support of the free edge.
The calculation according to the different integration methods and with a different number of integration points provides the following results for the center of the plate (grid point no. 28):
Overall, the results are easily comparable. However, there are noticeable deviations when using the trapezoidal rule, especially when there is a small number of integration points.