WP 961 consists of a beam mounted on two supports which is subjected to point loads. The beam is cut at one point. At that point there is a low-friction hinge with one degree of freedom. The force gauge indicates the internal reaction (shear force) at this point on the beam. An adjuster nut on the force gauge is used to align the beam horizontally and balance out any deflection.
The reactions are determined from the static conditions of equilibrium. To investigate the effect of the point loads in the beam, it is notionally split into two segments. Applying the method of sections, the internal forces and moments are plotted onto the two segments and calculated by way of conditions of equilibrium.
