The ability to predict material behavior under impact loading is very important in the design and manufacture of products. To predict product performance adequately, it is important to simulate the conditions under which the material is used.

Traditional impact tests often fail to provide the data required to evaluate and predict behavior under impact stress. An instrumented multivariable high-rate impact tester is designed to provide this information. The instrument is capable of testing materials of almost any configuration at velocities from 0.0127 to 12.7 m/s (30 to 30 000 in./min) and in environments simulating service conditions. Electronic instrumentation and a sophisticated computerized microprocessor simplifies the gathering, processing, and calculation of the impact property data. The graphic and calculated values permit a detailed analysis of impact performance.

The high-rate impact tester used at Owens-Corning Fiberglas Corp. is described, with examples of test programs in which the instrument capabilities were utilized to simulate the impact forces on boat, pipe, and tire constructions. Modifications made to the ram, or mode of operation, better simulate end-use conditions.

The results adequately predict impact behavior experienced under service conditions within a laboratory environment. This provides the scientist with a means of observing the impact phenomenon under laboratory conditions. As new materials are developed, characterization can be accomplished rapidly and at minimum cost. Screening of candidate materials can be accomplished without the time-consuming and expensive process of producing a product and conducting in-service tests.

The information developed can be invaluable for improving existing products and developing new products. By observing the test and evaluating the traces obtained, one can identify potential weaknesses in a product, which can be corrected by redesign or substitution of alternative materials.