FML tubular inversion for improved specific energy absorption

Abstract

In the transportation sector, circular tubular sections were widely chosen as energy absorbers. Research has shown that the designs made of tubular inversions effectively avoid the bending modes and assist in energy absorption smoothly and gradually, as can be observed from the respective (compressive) force-deflection curves. But metallic tubular inversions usually have low specific energy absorption capacity, due to their weight. The present study explores the use of fiber metal laminate inversions made up of a combination of metal and fiber, with a focus to improve specific energy absorption. The initial metallic design configuration has been proposed based on the packaging volume available. The design has been further improved by the addition of splines as stiffeners. The material of the inversion configuration is then changed to avoid metallic damage. The design has been further improved by the adoption of fiber metal laminates to improve specific energy absorption and ease of manufacturing. The energy absorption calculations have done using finite element analysis methods. The energy absorption capacity of the stepped tube configuration with splines have been compared with that of the fiber metallic laminate configuration and the specific energy absorption capability compared.