Corrugated edge margin effect on edge failure stresses in solid riveted metallic lap joints

Abstract

This paper presents investigated results from Finite Element (FE) linear static analyses of the solid riveted metallic lap joints with and without corrugated plate edges. The main objective is to study the impact of corrugated edge of single rowed riveted single shear metallic lap joint on edge failure occurrences such as edge wrinkling, edge shear out, and edge split. A solid riveted lap joint is simplest and mostly used permanent joint type in the aerospace industries. During any aircraft development, a detailed analysis of every design parameter of all the riveted joints is a significant part in reporting riveted joint strengths and weights. There are many studies reported on importance of design parameters of solid riveted metallic lap joints. However, the impact of edge margin's geometrical shape on the edge failure modes in the riveted metallic lap joints were very rarely carried out. Hence, the influence of edge margin's geometrical shape on stress distribution along the edge margin direction was not reported in the literature. As an initial part of this paper, the geometrical shape of the edge margins has been optimized to corrugated shapes in order to reduce the normal stresses along the edge margin directions. The next part of the study describes FE investigation of three varieties of solid riveted single shear metallic lap single rowed joints. Investigated samples are of 2024-T3 aluminum alloy, manufactured from a thickness of 2mm sheet and the solid rivet NAS1097AD6-7 made of 2117-T4 aluminum alloy. Metallic lap joints with one, two and four rivets in a single row cases are investigated. FE linear static analyses have been performed with edge margin of 1.5D and 2D on straight and corrugated shapes by keeping all other design parameters of the joint as constant. An average possible weight reduction per joint due to introduction of corrugated edge margins over straight edges has also been reported. Reduction in normal stresses along the corrugated edge margins compare to straight edge margins are presented as the main outcome of the study.