| In the current aviation manufacturing field, design ideas of aircraft parts are updated, functions of aircraft parts are changed from monotony to composite, lots of new materials are applied, shape features of aircraft parts are complex, and quality requirements of aircraft parts are high, so the process plan determined by the traditional experience has been failed to meet the needs of current development. With the improvement of finite element method, numerical simulation technology has been applied in the forming of aircraft sheet metal parts, which reduces the development cycle and cost of products efficiently. However, there are still many problems appeared in the practical CAE application, including un-profession, data losses in the transformation, fussy operation, separation between design and analysis, and repeated modeling. Thus a CAD/CAE seamless integration system for design and analysis of aircraft sheet metal parts should be developed.The work of this paper is supported by Research and Development on Rapid Synchronous Simulation Technology for New Generation Aircraft Sheet Metal Parts Forming from State Key Laboratory of Material Processing and Die & Mould Technology. Finite element algorithms for aircraft sheet metal parts forming are built, quality assessment criteria for aircraft sheet metal parts are present, and rapid simulation systems for aircraft sheet metal parts forming are developed based on CATIA V5 to study forming defects evaluation, forming features analysis and CAD/CAE seamless integration technology for aircraft sheet metal parts.Based on thickness strain, formablity limit curve and winkle limit curve, an optimization model is present to to study the effect of the initial blank size on the surface quality of aircraft sheet metal parts with using the finite element inverse approach. The effect of initial blank size on the skin parts has been studied from rolling direction, hardening exponent and friction coefficient of the aluminum alloy material.Based on forming features of aircraft sheet metal parts, a simplified model for elasto hydro forming is proposed, hydraulic pressure in the elasto hydro cavity should be loaded on the sheet metal part, and friction bewteen the elasto hydro layer and the sheet metal has been treated;an analysis model for skin stretch forming is put forward, the clamp is defined as constraint nodes located in the areas of the clamp mouth, the trajectory of the clamp mould is restricted;a theoretical model for extrusion stretch forming is presented, the clamp and the arm are defined as the whole movement mechanism, divergent nodes caused by dynamic effects have been controlled. The simulation algorithms for elasto hydro forming, skin stretch forming and extrusion stretch forming based on BT and BWC shell elements are developed by using the elastic-plastic three-dimensional finite element dynamic explicit method. And key algorithms are investigated, including the load method of hydraulic pressure and firction treatment in the elasto hydro forming, the trajectory load method of the clamp and the mould in the skin stretch forming, and the control method for divergent nodes in the extrusion stretch forming.Based on the research of the theory and algorithm for aircraft sheet metal parts forming, CAD/CAE seamless integration systems for rapid simulation of aircraft sheet metal parts have been developed firstly with the secondary development technology of CATIA/CAA, including the blank estimation system-BES for aircraft sheet metal parts, the elasto hydro forming system-EHFS, the skin stretching forming system-SSFS and the extrusion stretch forming system-ESFS. The integrated systems can be applied in the whole process of aircraft parts manufacturing, including product development, process optimization, mould designing and virtual forming, to realize the seamless integration with CATIA and overcome the limitations of CAE employed in the whole development of aircraft parts, contributing to low cost, good quality and high productivity.
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