Study On The Failure Strength And Influencing Factors Of Composite Connecting Structure

Composite materials are widely used in the aerospace field,such as the fairing of the launch vehicle,the fuselage of the aircraft,and some of the load bearing or non bearing structures on the wings.At present,the mechanical connection of the connector is still a hot and difficult problem in the design of composite structures.The most effective way is to use the test to study the stress distribution of the hole,but the test is very limited,and the cost of time and cost is too high.Based on this situation,with the development of the finite element software of computer,the numerical simulation is becoming more and more simple.Composite material is a kind of brittle anisotropic material,its composition is complex,and the form of stress is various,especially in the aspects of contact and damage.Based on the above,the main contents of this paper are as follows:1.Using ABAQUS finite element software to establish a three-dimensional simplified model to simulate the single bolt connection problem of composite perforated laminated plates.To verify the effectiveness of the model,simulation of hole edge stress distribution,and then adjust the geometric parameters,material parameters,effects of laminate stacking sequence,the preload,friction and bolt hole clearance on the hole edge stress distribution.2.Using the ABAQUS software to establish a three-dimensional finite element model to simulate the problem of single bolt double shear.The Hashin failure criterion used in material failure criteria,and then the model needs to be modified Camanho stiffness degradation model based on the simulation of tensile load,connection structure failure model and process,and Study on different influence factors on the strength of the.3.The three-dimensional finite element model is established to simulate the bolted single lap joint structure,and the proportion of the load distribution is calculated.The influence of the joint clearance on the distribution ratio of the bolt is studied.Moreover,the failure process of the connection structure is analyzed when the tensile load is applied,and the failure load is predicted.