Characterization of a structural adhesive in automotive environments

In order to achieve better fuel economy without sacrificing vehicle size, the automotive industry is motivated to utilize advanced materials, such as polymer composites, in primary structural components. When polymer composite structures are used, adhesive joining is often an attractive alternative to traditional fastening techniques and may in some cases be an enabling technology. However, successful integration of adhesively bonded materials in structural applications requires a thorough understanding of material performance. This research effort addresses characterization methods for adhesives emphasizing the durability of the material with exposure to the aggressive environments that may be encountered in typical automotive applications. Specifically, test method selection and fixture design for submerged tests will be discussed. Data will be presented for a candidate epoxy adhesive material. Studies include tensile, fatigue, and creep characterization at 21°C, 90°C, and -40°C and with exposure to brake fluid, distilled water, and alcohol.