Research On The Prediction Method For The Tensile Strength Of Aircraft Large Panel

"Made in China 2025" is the first ten year program of action to implement the strategy of manufacturing power in China, and puts forward the development of key areas, such as aerospace equipment and new materials.Aircraft lightweight is the central topic of modern air transport, and the application of new materials and new technology is the necessary way to the development of aircraft manufacturing industry.New aluminum lithium alloy fuselage panels welding technology has been established as a key research project in the development of China commercial aircraft, but China's mechanical properties of new stiffened panel and the welding performance of the relative lack.In order to promote the application of new material and new technology in aerospace structure,reduce test cost and improve research efficiency,it is significant to study the tensile strength prediction method of stiffened panel.In this paper, in order to selective research at the beginning of new materials and new technology application situation, estimated the tensile strength of the aircraft large panel structure in the absence of detailed damage parameters.Through the analysis of the main influential factors of the tensile strength of the panel, establish the theoretical calculation formula of the tensile strength of the panel.The finite element method is proposed to estimate the tensile strength of the large civil aircraft panel structure with the maximum tensile stress strength criterion and the maximum strain criterion.Estimated tensile strength of the aluminum lithium alloy 2060 skin and aluminum lithium alloy 2196 stringer composed of friction stir welded panel and fiber metal laminate panel with the theoretical calculation formula and the unidirectional static load tensile analysis model by the ABAQUS software.With the strength of materials A and B reference value,compared two kinds of panel structure tensile strength theoretical prediction value and finite element prediction value with experimental value,theoretical calculation value and finite element prediction valueof tensile strength of friction stir welded panel with experimental value deviation is in the range of 1.5%~3.8% and 0.5%~11.4%;theoretical calculation value and finite element prediction value of tensile strength of fiber metal laminate panels with experimental value deviation is in the range of 3.4%~6% and 1.7%~3.8%,finite element simulation can accurately forecast two panels fracture location.Considering the complexity of the influence factors of the tensile strength of the panel and the reliability of the single test results, the prediction accuracy of the method is acceptable.Prediction method of tensile strength of stiffened panel is presented in this paper,which can provide a reference for determining the stiffened panel structure material,process performance improvement and panel structure tensile test scheme.It is instructive for engineering and design of reinforced panels in aeronautical structures.