Bending collapse behaviour of hat-shaped tubular structure strengthened with CFRP sheet

Abstract

Three point bending experiment of aluminium tubular structure with hat cross-section was carried out under quasi-static and impact conditions. The structure was strengthened with carbon fibre reinforced plastic (CFRP) sheet. The objective is to exhibit the effective strengthening method for such tubular structure. The anvil speed was 10 m/s in impact test. The anvil force commonly showed a rapid increase in the early deformation stage and it changed to the gradual increase after yielding. The force reached peak followed by the decrease with saturating manner. The absorbed energy was approximately 10% greater under impact condition comparing with that under quasi-static one. The thickness of CFRP sheet was less effective. The energy absorption performance was slightly improved when the CFRP sheet was attached to the hat bottom. When the sheet was attached to both the hat top and the hat bottom, the performance was improved about 40% in maximum. It was improved about 10% when the hat sides were strengthened. It should be noted that the force did not exhibit the sharp drop, though other structures exhibited force decreasing stage.