Fracture
Plastic Pipes Conference Association # 1998 Gothenburg
Lawrence, Rasbash, Potter, Teo
Structured wall plastic pipe has been in existence for many years, but there remains a need for an appropriate method for assessing the durability of their comparatively thin walls in actual service. In normal operation this has not manifest itself as a problem, but the fact that damage can be sustained during maintenance operations has highlighted the deficiency. The possibilit) of damage has prompted much debate about how it might occur. It is not the purpose of this paper to pursue this ongoing debate but clearly these procedures are capable of imposing an impact condition on the internal wall of the pipe. To address the problem of determining a pipe's resistance to these practices, it has been suggested by some in the UK Water Industry, that the use of an impact test. already existing as an IS0 standard, might provide an insight. However. this established standard was designed to assess the impact characteristics of flat injection moulded plaques or samples cut from sheet but structured wall pipe products are by their very nature contoured and for this approach to be viable, considerable techrucal difficulties have to be overcome. This paper discusses briefly the need and then outlines an approach that minimises the structural and dynamic problems that can occur when accessing samples that have a complex geometry.
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