ISSN: 0884-6804
CODEN: JCTRER
Page Count: 10

A Loading Rate and Environmental Effects Study of Adhesive Bonded Sheet Molding Compound Joints
Sanders, BA
Senior project engineer and manager, General Motors Manufacturing Development Staff, General Motors Technical Center, MI

Wang, TK
Senior project engineer and manager, General Motors Manufacturing Development Staff, General Motors Technical Center, MI

Lindholm, US
Director, Southwest Research Institute, TX

Abstract

As sheet molding compound (SMC) materials become more widely used in today's automobiles, the need for economical and reliable methods of joining them increases. In this paper, the static and dynamic behavior of SMC-R25^® and SMC-R50^® single lap shear joints, bonded with a two-part urethane adhesive under various loading and environmental soaking conditions, are determined and analyzed. Engineering properties of the adherends (substrates) and adhesive are also presented.

This experimental study has revealed that over a wide range of loading rates, there is no significant variation in lap shear strength. Modulus, however, increases significantly with increasing rate of loading. A 30-day exposure to a range of automotive related fluid environments does not produce an appreciable loss in either static or fatigue strength of SMC-R25 and SMC-R50 lap joints. Most of the joints are found to separate predominantly in the adherend, but no strong correlation appears between separation mode and lap shear strength of the joint.

Keywords:
composite materials, adhesives, lap joints, automobiles

Paper ID: CTR10743J
DOI: 10.1520/CTR10743J
ASTM International is a member of CrossRef.