Study On The Strength Of Rivet-bonded Hybrid Joint Considering Forming Process

With the application of new materials such as aluminum alloy,high strength steel,composite material in the automobile body,new connection technology such as adhesive,riveting and rivet-bonded joint achieve a rapid development.adhesive bonding technology has unique advantages in dissimilar material connection and composite material connection.As a form of mechanical connection,riveting has higher reliability.The combination of these two kinds of connection can achieve better connection effect.This thesis focused on the strength characteristics of rivet-bonded single lap joint under the condition of tension and shear load using experimental and simulation methods considering forming process.And the research work was carried out in the following aspects:(1)Different types of single lap joints were tested which were made according to adhesive technology and rivet technology.And the strength of rivet-bonded single lap joints under the condition of tension and shear load was studied,while rivet joints and adhesive joints were set as control groups.Meanwhile,the carrying capacity of rivet-bonded single lap joints under two different process routines(adhesive cured before riveting process;adhesive cured after riveting process)was studied.In order to analysis the impact of riveting process on joint performance,dynamic DIC technology was adopted to monitor the distribution and change of strain field of adherend surface during riveting process.(2)Johnson-Cook model was selected for mental materials and cohesive zone model was selected for adhesive which is necessary for the simulation of rivet-bonded hybrid joints.Johnson-cook model parameters were obtained by designing standard tensile tests,shear tests,and notched test,while cohesive zone model parameters for adhesive were obtained by referring to relevant literature.Corresponding FEA model of three experiment above were established in ABAQUS,and the parameters of Johnson-Cook model were verified through comparison with experiments.(3)The three-dimensional model of single lap rivet-bonded joint was established by ABAQUS consisting of five parts: rivet mandrel,rivet body,the adhesive,upper plate and bottom plate,and they were assembled by assembling constraints.Cohesive zone model parameters and Johnson-Cook model parameters were assigned to corresponding parts to complete the definition of material property.The simulation of riveting process and joint strength prediction was realized by establishing two analytical steps.According to the simulation results obtained from Step-1(riveting process simulation),The deformation and damage of the joint was evaluated,and the results were consistent with the experimental results.The accuracy of the joint strength prediction model was verified by comparing the load-displacement curve obtained in step-2(joint strength simulation)with the experiment.The failure behavior of adhesive and rivet was analyzed according to the strength prediction model of single lap rivet-bonded joint,which provided a foundation for the performance evaluation and optimization of rivet-bonded joint.