Study On The Influence Of Different Boundary Constraints On Crashworthiness Of Composite Waved Beams

As a typical composite energy absorption structure,composite waved beam is widely used in helicopter anti-crash energy absorption structure.How to design high-efficiency energy absorbing composite energy absorption elements has become a hot spot in current research.In this paper,two constitutive models are used to study the energy absorption capacity of composite waved beams,and the effects of corrugation number and boundary support conditions on the energy absorption performance are analyzed.The main work and research results are as follows:Based on the ABAQUS software platform,the shell element model with equivalent elastic-plastic constitutive structure and the three-dimensional solid model with composite material constitutive structure are established for single-wave and three-wave composite corrugated beam structures.The rationality of the two models is verified by the comparison between the results of the calculation and the experimental results in literature.The results show that the three-dimensional solid model of the composite material is more consistent with the experimental results because it takes the different modes of failure of the composite material into consideration.The energy absorption performance of single wave,two wave,three wave,four wave and five wave composite corrugated beam is analyzed by elastic-plastic constitutive model and composite constitutive model.The influence of the number of corrugation on the specific energy absorption ability of the composite is studied.The results show that the single wave structure is easy to cause the torsion instability of the structure due to the free boundary of both sides,and the specific energy absorption ability is low.With the increase of the number of corrugation,the energy absorption ability of the single wave structure increases gradually and tends to be stable.Based on the elastic-plastic constitutive model and composite constitutive model of single wave structure,the effects of simply supported boundary conditions,elastic support boundary conditions and periodic boundary conditions on the energy absorption capacity are studied.The results show that the specific energy absorbing capability of periodic boundary conditions is the same as that of multi wave structure,which lays the foundation for subsequent optimization of the absorbing energy structure of corrugated beam based on the single wave model.