2D In-Plane Loads

In-plane loads break down into two categories, pre-stress loads and initial strains. Pre-stress loads are defined as a force per unit width in either x, y or both x and y directions, along with an offset from the neutral axis. Initial strains are defined in either x, y or both x and y directions, but no offsets are permitted. The pre-stress loads can be converted directly to a set of element stresses, which are integrated over the element to get the nodal forces. The offset force gives rise to a moment on the element so

$$\sigma_{p} = \frac{F}{t}\qquad \sigma_{b} = \frac{6M}{t^{2}} = \frac{6Fz}{t^{2}}$$

The initial strains can be converted to stresses in a manner analogous to that used for thermal loads.

Note: In GSA, loads can be applied to a list of members or elements. Any loads applied onto members will be automatically expanded into the appropriate elements loads in the solver in order to analyse the model.