Rigid compression-only support

This type of support gives a full support (fixing) when under compression. If there is a tension in this type of support, the support ceases to give any support and is "absenting" from the model.

Let’s assume a simply supported beam with an additional intermediate support (intentionally we do not speak about continuous beam in this context). The intermediate support is of discussed compression-only type. As a result, the support acts only if some load is applied in downward direction.

First, let’s apply a vertical load acting in downward direction.

Second, let’s apply a vertical load acting in the opposite, i.e. upward, direction.

The following set of pictures shows the results for individual loads. Diagrams of reactions and deformation are shown.