Fracture behaviour of UPVC thin tubes at high loading rates

The use of fracture mechanics concepts in describing the failure behaviour of unplasticized poly(vinyl chloride) at high loading rates is studied. An impact test is employed which uses a gas pulse generated by a shock tube to load thin cylindrical specimens. These controlled pulses are used to internally pressurize specimens containing machined notches of different lengths or unnotched specimens. The specimen and the apparatus are both instrumented such that the pressure pulse and the resulting strain in the specimen are monitored throughout the tests to the point of fracture. Linear Elastic Fracture Mechanics (LEFM) is successfully applied to describe the fracture behaviour of the specimens at room temperature over a wide range of loading rates. A criterion is proposed by which the values ofK _c andG _c can independently be obtained over the range of the loading rates applied.