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The Use of recently Developed Experimental Methods and Modelling Techniques to study Crack Propagation in Viscoelastic Materials

 

Fracture & Resistance # 1992 Eindhoven

Two novel techniques have been applied to the problem of determining the fracture toughness of polyethylene appropriate to the situation of rapid crack propagation in pipe systems.
Agreement is found between the data from the two methods used for evaluating four grades of polyethylene of widely different toughness. By implication, either technique is valid for determining fracture toughness, but each method has a wider utility depending upon other evaluation requirements.


Increasingly, polyethylene (PE) is being used in water and gas pipeline systems for which the requirements are rigorous and demanding. In particular, there is a need for high fracture toughness both for sustained long term static loading and short term impact loading. As systems grow and pipes of larger diameter and wall thickness are required, the likelihood of brittle failure under plain strain conditions increases. The need for better information about the resistance of materials to this type of rapid crack propagation is essential.

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