INSTRUMENTED IMPACT TESTING OF POLYETHERSULFONE

The impact behavior of polyethersulfone has been studied using a specially constructed instrumented impact testing machine. This machine is of the pendulum type and the samples are fractured in three-point bend loading. It is shown that accurate force/deformation curves can be obtained, in spite of complications due to flexural vibrations of the test sample. Measurements were made on both sharp-notched and blunt-notched specimens over a range of crack lengths. It was found that the sharp-notched samples could be analyzed in terms of fracture toughness whereas the blunt-notched samples corresponded to a constant critical stress at the root of the notch.