EVALUATION OF ADHESIVE PROPERTIES USING THE IOSIPESCU SHEAR TEST METHOD

摘要

There are a number of test methods used to determine the mechanical shear properties of structural adhesives. The more common of these are listed in standards such as found in ASTM Standards. Most of the methods have issues with either specimen preparation or testing procedures, and/or other short comings. Either the specimen geometry is complex and difficult to manufacture or the testing procedure and test data acquisition is very demanding. For example the simplest test geometry, a single-lap joint, from ASTM D1002 does not produce adequate results due to global load eccentricities. Whereas, the thick adherend test specimen eliminates these single-lap joint problems, but is a complex specimen to manufacture and test results are typically difficult to obtain. Over the past 20 year the Iosipescu shear test method has been applied to composite materials in many instances and more recently on adhesively bonded joints. The testing procedure is relatively simple, but test specimen geometry for adhesively bonded joints is difficult to manufacture. An alternate test specimen geometry based on the single-lap joint is proposed. When this simple test specimen geometry is combined with the simple test method provided with the Iosipescu test method the measurement of adhesive shear properties is significantly enhanced. Results from testing the specimens are compared with common adhesive systems from vendor data.