TWI Industrial Member Report Summary 583/1996
S M Tavakoli and R H Leggatt
Polymeric materials are susceptible to degradation during processing or in service. This can lead to deterioration in properties and premature failure.
During welding, polymers are exposed to elevated temperatures and considerable mechanical forces are applied to the viscous polymer. This process can generate thermal and residual stresses and initiate degradation reactions, thus affecting the long-term performance of the welded components. There is no established technique available for measuring residual stresses in thermoplastic welds. Therefore, it became necessary to develop a method for determining residual stresses in welds.
- To develop a technique for measurement of residual stresses at welds in polymers.
- To generate data on residual stresses at welds in polyetheretherketone (PEEK), polyethersulphone (PES), polyetherimide (PEI), acrylonitrile-butadiene-styrene (ABS) and glass- reinforced (GR) polyester.
- To determine the effect of ageing on residual stresses, mechanical properties and toughness in PEEK.