Propagation of Elastic Impact in Beams in Bending

Abstract

Abstract A theoretical and experimental comparison is made of the strain propagation in steel beams impacted by a sharp, transverse blow. The theoretical analysis is based on an earlier paper by Dengler and Goland, in which a solution based on the Timoshenko bending mechanism is deduced. (An analytical error in this paper is corrected here.) The experimental work was performed on a square beam, impacted by a steel sphere. Measurements are reported both for the strain propagation in the beam and also for the history of forces acting between the ball and beam. The results of the comparison show excellent agreement between the observed and predicted strain propagation, so long as the beam behaves essentially in bending. It is pointed out in the discussion, however, that many impacted beams do not perform essentially in bending, so that the present work does not apply. A small-amplitude high-frequency strain component, not properly predicted by the theory, is also encountered in the experimental data.