Theoretical analysis on the collapse mechanisms of thin-walled composite tubes

Thin walled tubes are often used as impact absorbing elements in automobiles and other transport vehicles. Round cylindrical and conical shells made of composite material prove to be popular energy absorber as they provide reasonably constant operating force, which is the primary characteristics of an ideal absorber. Based on experimental observations, a theoretical procedure is established to predict the post collapse load-compression characteristics of the composite shells. Analytical expressions were obtained to predict the average crush load and the crush length in a crush cycle for the composite conical shells as well as for the cylindrical tubes. The results so obtained were compared with the experimental values available from the literature.