Influence of Stack Orientations on the Static Strengths of SPR Joints

Abstract

Abstract. To improve fuel efficiency and reduce greenhouse gas emissions, lightweight materials, such as aluminium alloys, are used increasingly in automotive manufacturing. Currently, self-piercing riveting (SPR) is a major technology used by manufacturers to join aluminium body structures due to its advantages over other joining technologies. When different materials are joined together, different stack orientations can be used. To find out the influence of stack orientations on joint strength for further structure optimization, in this paper the joint quality and the static strengths of three pairs of twothickness stacks with different orientations were studied. The results showed that by joining the thicker material as a bottom material rather than a top material, joint interlocks were improved. As to the mechanical strength, for the stacks with both top and bottom sheets as AA5754, when a thicker sheet was joined as a bottom material, the joints had stronger static strength, and for stacks with 3.0 mm AA5754 and 2.0 mm AA6008T61, when the 3.0 mm AA5754 was joined as a bottom material, the joints had stronger static lap shear strength but weaker static T peel strength.