Method and apparatus for dynamic testing of structural joints

Abstract

The dynamic testing technique is used during the design phase of structures and series production. This test evaluates the structural capacity, especially of the assemblies, to withstand different forces and rates of impact encountered under realistic operational conditions. This study proposes a magnetic pulse exciter for high-speed impact loading in dynamic tests because of its capability to provide single and repeatable pulse loading over a wide range of force up to 20 kN and pulse durations from 10 up to 1000 ms. The method transforms accumulated electrical energy in a capacitor bank into mechanical energy. For experimental investigations, flat and cylindrical coil devices were used for a capacitor-type pulse current generator. The proposed method has been experimentally validated on timber beams in a specified volume of force loading. The technique demonstrated a potential for controlling force and energy parameters. The effects of operating voltage on coil and ‘metal plate - coil’ distance on the amplitude of dynamic loading have been investigated. Aluminium and steel plates fastened to the object at the point of impact were used to improve excitation efficiency. The developed technique can be used in experimental studies on model joints and real objects.