The article explains how stress and forces in rigid-plastic beams are analyzed in a new way called strain-gradient plasticity. The researchers found that including microstress and moment-stress is important for understanding bending moments. They used three methods to find the relationship between bending and plastic strain measures. Results show how bending moments and curvature are related in different scenarios, like linear and nonlinear hardening. In thin foils, lateral bending moments help maintain a specific mode of deformation.