Impact of riveting sequence, pitch and gap between sheets on quality of riveted lap joints

Abstract

This thesis presents a study on the effect of controllable process parameters in riveting (i.e., such as the sequence of riveting, distance between rivets (pitch) and gap between sheets) on the quality of riveted lap joint and formed rivet. The quality of a riveted lap joint is characterized by sheet metal bulging, sheet material growth, residual stress level on sheets and rivets, and post riveting clearance in the joint. The quality of a formed rivet is often determined by the geometry of its head formation. This study is to determine the best riveting sequence for riveted lap joint in sheet metal assembly with 1/8" nominal diameter of flat head tinner rivet on 0.064" thick aluminum sheet. The study is performed using finite element simulation of riveting process. Statistical design of experiment is employed to analyze the simulation data of riveting process along with the effect of individual factors, their interactions and relationship with the quality parameters of riveted lap joint in sheet metal assembly. A good combination of riveting process parameters is found that minimizes the residual stress in sheets and rivets, bulging and material growth in sheets and reduces the chance of post riveting clearance in riveted lap joint.