Analyzing thick-section composites lug with hole containing boundary sleeve

A finite element (FE) modeling method with cohesive interface and sublaminates was proposed to study interlaminar stress distribution and strength of thick-section composite materials lug. And numerical calculation was carried out on the thick composite laminates three-point bending problem; effectiveness of modeling method for thick-section composite materials stress calculation was verified, Based on this, a three dimensional (3D) FE model of thick-section composite materials lug is designed; then the 3D stress distribution along the hole edge and failure mode of the lug subjected to axial load are discussed. The results and their analysis show preliminarily that: (1) the failure stress and damage position are mainly concentrated in the no contact region of the hole-axis; stiffer metal sleeves reduce the interlaminar stress concentrations of hole edge, however, this and higher radial tensile stresses in the region lead to reduced carrying capacity of the sleeves adhesive; (2) the adhesive of sleeves fails before the thick-section composites lug; this destroyed the integrity of the protective structure and will adversely affect the strength of the thick-section composites lug.