Post-buckling analysis of composite thick-skin multi-spar wing box under bend and twist load

摘要

In this paper,the bending static experiment and finite element method (FEM) are used to study post-buckling performance of the composite thick-skin multi-spur wing box. The well agreements of the load-displacement curves between experiment and FEM show that the FEM modeling is credible. Based on this FEM model,the post-buckling behaviors of the wing box under two different loads: bend and twist load,are investigated. The buckling behavior is determined by tracing the load-deflection curves using non-linear arc-length method. Numerical results show that the structure still has ability to support load in post-buckling stage under both bend and twist load. The buckling of the structure is local. The buckling occurs at both the composite skin and the alloy webs under bending load but only occurs at alloy webs under twist load.