Research On Skin-side Pressed Automated Drilling Process Of Sandwich Thin-structure

To insure the assembly quality and to improve assembly efficiency of the aircraft, lightweightautomated assembly systems are more widely used in contemporary aircraft assembly process. As thekey of application technology of lightweight automation systems, skin-side pressed drilling processeshas an important impact on the quality of automated drilling. Based on finite element simulation,parameter optimization and skin-side pressed experiment, this paper focus on studying drillingprocess parameters optimization that applies to aircraft section joint. The main work and researchingcontents include the following:1. The impact of the pressed force and temporary fastener positions on interface gap is analyzedby using the nonlinear finite element method. Based on the characteristics of skin-side pressed drillingsystem, analyze the main parameters and its scope of the interface gap. For a regional aircraft fuselagejoint structure, build finite element simulation model on frame considering preload of temporaryfastener, give the recommended preload, pressed force and temporary fastener positions.2. Present a skin-side pressed drilling optimization method based on the response surface method.The sample points are designed used central composite design which calculated with finite elementsimulation, then the response surface model is constructed to substitute mass finite element analysisduring the optimization of process. And verify the reliability of response surface model throughcomparing the calculation value of finite element analysis and response surface model. Based on theresponse surface model, the impact on interface gaps is analyzed. The rational process parameters areachieved by using adaptive simulated annealing on response surface model.3. A experiment is conducted to verify the skin-side pressed drilling optimization methodpresented in this paper. The validation scheme is designed include test coupons and tooling, theexperiment is conducted used the press force as control variable. The reliability of skin-side presseddrilling parameters optimization is verified by comparing the experiment results and the simulationresults and optimization results.The optimization presented in this paper can overcome shortcomings of the long simulation timeand difficult introducing optimization algorithms using finite element model. That can providetechnical reference for the application of lightweight automated assembly systems.