Research On Characteristics Of CFRP Hat-shape Beams Under Axial Crushing And Three-point Bending

With the trend of lightweighting and crash safety becoming increasingly popular in automotive industry,more and more automotive structures of traditional metal materials are replaced by carbon fiber reinforced polymer(CFRP),which has outstanding mechanical performances.As typical vehicle body structures,CFRP hat-shape beams are studied on the axial crushing and transverse bending behavior by experiments and numerical simulations.The main research contents are:(1)Researches on the material mechanical properties: axial tensile and three-point bending tests of the CFRP specimens manufactured by autoclave molding were performed,and the material parameters in simulation were obtained through finite element analysis.(2)Researches on quasi-static crushing characteristics of the beam with hat-shape cross section: based on the axial quasi-static crushing experiments,the influences of ply angle,ply number and the section shape on the energy absorption characteristics of the structure are studied.In addition,based on Chang-chang failure criterion,the multi-layer shell finite element model of CFRP composite hat-shape beam is established,and the effect of material strength on the crush characteristics is analyzed.(3)Researches on quasi-static bending characteristics of the beam with hat-shape cross section: based on the transverse three-point bending test,the bending characteristics of CFRP hat-shape beam are analyzed by combining the failure mode and the energy absorption characteristics,and the influence of the ply angle,section shape and ply number on the bending performance of the structure is investigated.The three-point bending process of the hat-shape beam is simulated by the multi-shell finite element model,and the influence of material strength on the bending characteristics of the structure is studied.In this paper,some valuable conclusions have been drawn on the axial crushing and transverse bending responses of the CFRP hat-shape beam,which provides a great significance for the application of composite thin-walled structure in further study.