DESIGN OF MULTIPLE-ROW BOLTED COMPOSITE JOINTS UNDER GENERAL INPLANE LOADING

A special purpose finite element method for design of multiple-row com posite joints under generalized in-plane loading is presented. The str ess analysis is carried out in two steps. In the first step (source an alysis), the distribution of applied load within the joint and between the fasteners is determined. In the second step (target analysis), a series of detailed stress analyses of regions containing single bolt h oles is performed to determine the stress distribution around the bolt holes. Far field stress distributions obtained in the source analysis are automatically transferred to the boundaries of the target models. The failure analysis includes evaluation of the failure modes (net-se ction, bearing and shear-out) according to simple point stress criteri a. Experiments were performed using single-bolt specimens to validate the target and failure analyses for a graphite/epoxy material system. A complete analysis of a multiple-row glass-fiber/polyester joint is c arried out. Computed results show good agreement with experimental dat a.