MART Three-Hinged Arch Unit

The Three-Hinged Arch Unit "MART" allows the student to become familiar with three-hinged arches, to calculate the bearing forces (for point load, for uniformly distributed load and for moving load), to investigate the influence of the load on the horizontal thrust in the supports, to determine the influence lines and to calculate support reactions.

The unit includes two long arch segments and one short segment, of which two at a time are connected by a central hinge, producing a symmetrical or unsymmetrical three-hinged arch. The arch segments are easily interchangeable. Moreover, the arch segments have two side hinges at their support, thus creating the three hinges.

The left hand hinge allows the arch section to rotate and move horizontally. The right hand hinge is held in position although it allows rotational movement of the arch section.

The arch under investigation can be loaded using a point load, a uniformly distributed load (by weights) or two moving loads, which simulate a vehicle.

The set of weights compensates for the support reactions of the side hinges, thus enabling a comparison between calculated and actual measured values.