Experimental study into the energy absorbing characteristics of top-hat and double-hat sections subjected to dynamic axial crushing

Dynamic axial crushing tests have been carried out on thin-walled top-hat a nd double-hat spot-welded mild steel sections which are used for structural crashworthy purposes in the automobile industry. Several post-test collaps e modes were identified for the structures and the associated energy absorb ing characteristics have been examined and compared with previous tests. A new empirical equation is suggested which relates the dynamic structural ef fectiveness to the structural density of top-hat and double-hat sections.