Experimental apparatus for the deflection analysis of statically determinate and indeterminate plane frames

A rigid-cornered steel portal of either U-shape or S-shape is clamped at one end; the opposite end can be left free (statically determinate cantilever frame) or seated on a roller (statically indeterminate single-redundant frame). Point loads at arbitrary positions deform the frame; two dial gauges record the horizontal sway and vertical deflection. The apparatus gives the student a platform on which to apply first-order elastic theory, the principle of superposition and - above all - the principle of virtual work to compute both deformations and the redundant support reaction, then compare directly to the measured values.