Simulation Analysis On The Whole Process Of The Interface Failure Between The Hatch Truss And The Skin

Adhesive bonding technology is the main bonding technology of composite materials,which has been developed rapidly in aviation,aerospace and other fields.Although the bonding technology has many advantages,but because the bonding structure has a variety of fibers,different laying methods and adhesive layers,the mechanical behavior is complex,people’s research on its bearing capacity,damage mode and reliability is not in-depth.It has been applied to the weak bearing structure,and its excellent performance has not been fully developed.For composite bonded structures,the properties of bonding interface play an important role in the overall performance,ultimate bearing capacity and damage characteristics of materials and structures.Therefore,the analysis of interface damage initiation,evolution and failure process is very important for the accurate evaluation of material and structure performance and subsequent design applications.In this paper,the constitutive relation of cohesion model and its parameter determination method are introduced in detail.On this basis,a new interface constitutive parameter determination scheme is proposed.Through the establishment of composite material bonding structure in theory and experiment with state of the finite element model of cohesion,to specimen of theory of state as the main method combining finite element simulation test state simulation to study the different configurations of CFRP laminated plate bonding structure under different loading ways of the ultimate bearing capacity,interface damage pattern and damage extension rule,the correctness and feasibility of the scheme for determining constitutive parameters are verified,and the influence of each parameter on the interface strength is discussed.The results show that the adhesive structure has stronger bearing capacity and better performance advantage than the screw structure without considering the interface damage;In this paper,a complete scheme is proposed to predict the fracture parameters of the cohesive force model by combining the experiment with the finite element simulation,and the constitutive model of the bonding structure interface is obtained by this scheme.The feasibility of this scheme is proved by the comparison of the theoretical and experimental simulation results of the cohesive force model;There are some differences between the theoretical and experimental numerical simulation results based on cohesion model,so it is necessary to carry out the experimental simulation analysis for the bonded structure when the accurate test results must be obtained through simulation in engineering practice;The loadingmode and the physical properties of the composites on both sides of the bonding interface jointly determine the damage expansion law of the bonding structure;The loading mode plays a leading role in the damage expansion law of the bonding interface and the ultimate bearing capacity of the structure;The ultimate bearing capacity of composite bonded structure is related to loading mode,bonding length,thickness of adhesive layer,physical properties of the bonded material and other factors;The influence of each factor on the ultimate bearing capacity is weakened in turn,and the degree of influence of the physical properties of the bonded material on the ultimate bearing capacity is sensitive to the loading mode;The ultimate load-carrying capacity of the composite bonded structure varies linearly with the thickness and length of the adhesive layer.The work in this paper has reference significance for the study of the ultimate bearing capacity and damage behavior of composite bonded structures,and provides a strong theoretical support for the design and application of composite bonded structures.