Impact overload tests on triangulated steel frames

Abstract

Tests are reported on sixteen pinjointed, triangulated steel frames, subjected to impulsive overload. The frames were statically determinate, consisting of a single strut, tie and connexion; the load was applied by a spring loading device. Records were taken of the transient force pulses and high-speed photographs showed the various modes of failure. The load on frames which failed by yielding at the tie exceeded the corresponding static value by a factor approximating closely to the proportional increase of yield stress under dynamic loading. In some experiments strut failure occurred under a transient load many times the corresponding static value. In many both members showed signs of failure with a change of mode during the course of deformation.