Transient response of thick circular and square bars subjected to transverse elastic impact

Abstract

The objective of the studies presented in this paper was to understand the transient response of thick circular and square bars subjected to transverse elastic point impact. It is shown that the transient response is composed of a number of resonant frequencies caused by cross-sectional modes of vibration. The individual cross-sectional modes and their corresponding natural frequencies were determined using plane strain and three-dimensional finite-element models of circular and square cross sections. The first few modes for both circular and square cross sections are shown. Subsequently, three-dimensional finite-element models of circular and square bars were used to determine the transient response caused by transverse point impact. To verify the results obtained from the numerical models, experimental studies were performed on a 0.4-m-diam circular bar and a 0.3-m square bar. These specimens were representative of full-size concrete columns—typical barlike structural elements. The results of these experimental studies were in excellent agreement with those obtained from the finite-element analyses. A future paper will present the results obtained from numerical and experimental studies on rectangular bars.