Analysis of Influence of Testing Equipment on Impact Data of Brittle Polymers Using an Inverse Method

VALERIA PETTARIN; PATRICIA FRONTINI; GUILLERMO ELICABE; MARTA RINK; ANDREA PAVAN

Viña del Mar, Chile

Simposio; II Simposio Argentino-Chileno de Polímeros ARCHIPOL II; 2003

This work is devoted to the analysis of the influence of the testing equipment on impact load measurements. Instrumentation of a traditional impact machine offers valuable information on the fracture process, on the type of fracture and on the extend of plastic deformation. In an ideal situation the outcome of an instrumented impact test would be a record of the applied force on the tested specimen versus time. However, in a real situation the bouncing of the specimen-machine system and specimen inertia cause periodic variation in the measured force signal distorting the sought result. Therefore, a dynamic analysis is necessary to deduce the actual loading of the specimen in order to adopt fracture mechanics theories under impact conditions. The results of this work shows that the combination of a model mechanically equivalent to the system specimen-impact test instrument and the inverse problem concept is appropriate to obtain an accurate estimation of the actual flexural curve in impact testing that not depends on the testing equipment.