MATERIAL CHARACTERIZATION PROBLEMS LEADING TO INACCURATE COMPOSITE DESIGN ALLOWABLES

Obtaining of accurate test data in composite material characterization is critical in developing cost efficient and optimum composite design. To minimize/eliminate meaningless make and break testing, it is imperative to understand the effect of various factors which influence the test data and hence the design allowables. This paper addresses the effect of various factors which lead to material characterization problems resulting in inaccurate composite design allowables. These factors which are generally inadvertently ignored or not accounted adequately by the material testing community, include the effect of test method, test conditions/parameters, specimen design, specimen fabrication (processing), specimen manufacturing defects, specimen physical properties, specimen preparation, specimen conditioning, sampling problems and statistical treatment. By accounting for the effect of these test factors, one can obtain meaningful and accurate test data by minimizing the sources of errors and improving the test productivity by doing it right the first time.