Failure Analysis Of Integral Stiffened Composite Panel Considering Stiffness Matching Under Uniaxial Compression

With the rapid development of advanced composite materials, stiffened composite thin-wall structure is a bearing structure of typical parts, has been widely applied in the aerospace field. Under compression, integral stiffened plate composite has complex failure modes. As the skin and stiffener reinforced together through the interface connection, the structure is easy to cause interfacial debonding due to high stress of interface, as well as the much earlier global buckling behavior if the stiffness matching characteristic of skin and stiffener is not properly designed. All of the above can induce a sudden structure collapse. Therefore, the numerical analysis for investigation the effects of the stiffness matching characteristic of skin and stiffener on the bearing capacity and corresponding failure modes considering progressive damage has been carried out, the main topics are shown as follows:(1) The effects of progressive damage degradation on the buckling and post-buckling behavior has been studied.(2) The limit load and failure mode for typical I-stiffened plate with various rigidity matching characteristic by considering different geometrical parameters has been carried out, in which, the effect of interface strength on buckling load and limit load is also considered.(3) By keeping the equivalent bending stiffness of the rib as a same value when varying other geometrical parameters, the instability behavior and failure modes for typical Hat-stiffened plate with different rigidity matching has been carried out.The research of this paper is supported by the Fundamental Research Funds for the Central Universities "The failure theory and optimization design of integration of light weight thin wall composite panels"(DUT12LK02,2012-2014) of Dalian University of Technology and the National Basic Research Program of China (No.2014CB046506).