Research On Drilling Technology Of CFRP/TC4 Stacks Based On ABAQUS

Owing to their characteristics like low density and high specific strength,composites are widely used in aircraft,automobile and construction.CFRP(Carbon Fiber Reinforced Plastics)and titanium which are both difficult-to-machine materials are common used in aircraft.There is the assembly problem during combined utilization of CFRP and titanium.Rivet connection and bolt connection are the mostly used in assembly of stacks,which needs drilling CFRP and titanium.Considering assembly accuracy and drilling efficiency,these two kinds of materials should be manufactured simultaneously.Both of CFRP and titanium are difficult-to-machine materials.There is difference between manufacturing characteristics of CFRP and titanium.How to choose proper drills is still a challenge.Experiment method has disadvantages like long preparation period and high cost which can be overcome by simulation method.Therefore,this article develops simulation research on CFRP/Ti6Al4 V stacks.CFRP model and Ti6Al4 V model are developed respectively based on ABAQUS and relevant experiment is developed to validate the accuracy of model.Then the influence of drill point angle and helix angle on thrust force and torque and influencing factors are studied.Influencing factors on CFRP delamination are studied.The main research contents are as follows:(1)To develop CFRP/Ti6Al4 V finite element model,drill model is developed based on UG software and imported into ABAQUS software.(2)Based on this model,drilling simulations of Ti6Al4 V and CFRP are developed respectively.Comparing simulation result and relevant experiment result to validate the accuracy of models.The influence of point angle and helix angle on thrust force and torque of Ti6Al4 V during drilling CFRP/Ti6Al4 V is studied.(3)CFRP delamination damage model is developed based on Cohesive element to study CFRP delamination damage during drilling CFRP/Ti6Al4 V.Relevant experiment is developed to validate the accuracy of model.Based on the delamination damage model,the influence of point angle,uncut number of plies,CFRP layups and thickness of Ti6Al4 V on delamination damage area is studied respectively.Delamination ratio FS and its calculating method are used to analyze the influence rule of above factors on delamination damage area quantitatively.The image of delamination damage area is binarization processed by PS software and Fs is calculated by MATLAB.