Structural Stress Method to Evaluate Fatigue Properties of Similar and Dissimilar Self-Piercing Riveted Joints

Harish Rao,Garret Huff,Jidong Kang,Katherine Avery

doi:10.3390/met9030359

Abstract

In this paper, we discuss the application of a simple Battelle structural stress model to evaluate the fatigue life of a self-piercing riveted (SPR) carbon-fiber-reinforced polymer (CFRP) composite to aluminum AA6111. The analytical model accounts for the forces and moments acting on the rivets to determine the structural stresses which were then plotted against the laboratory-generated fatigue life data. The master S-N curve determined in this study thus accounts for various factors such as the stacking configuration, rivet head height, and fatigue load ratios. The analytical model used in this study was able to collapse a large number of fatigue life data into one master S-N curve irrespective of stack-ups, rivet head height, and load ratios. Thus, the master S-N curve derived from the model can be used to predict the fatigue life of the SPR joints.

Highlights

Self-piercing rivet (SPR) has emerged as an economical and effective technique to join dissimilar and similar materials alike [1,2,3]
The aluminumto-aluminum SPR joints produced with FHH exhibited the highest overall lap-shear failure load, and the carbon-fiber-reinforced polymer (CFRP)-to-aluminum produced with FHH exhibited the lowest overall lap-shear failure load
In lap-shear joints tested at load ratio R = 0.1 and at a maximum normalized fatigue load range below 0.40, joints produced in CFRP-to-aluminum with a PHH exhibited longer fatigue life compared to those produced with FHH

Summary

Introduction

Self-piercing rivet (SPR) has emerged as an economical and effective technique to join dissimilar and similar materials alike [1,2,3]. This could potentially play a crucial role in introducing light aluminum alloys and fiber-reinforced polymers as an attractive alternative to lightweight steels due to their potential to achieve a high strength- and stiffness-to-density ratio [4]. CFRP to aluminum alloys [6,7,8,9,10,11,12,13] These studies have investigated the quality of the joint affected by die geometry [10], in-plane distance between the rivets [13], and oil pressure in a hydraulic system [11,12]

Methods

Results

Conclusion