On the interpretation of lateral manganin gauge stress measurements in polymers

摘要

Encapsulated wire-element stress gauges enable changes in lateral stress duringshock loading to be directly monitored. However, there is substantial debatewith regards to interpretation of observed changes in stress behind the shockfront; a phenomenon attributed both to changes in material strength and shock-dispersion within the gauge-encapsulation. Here, a pair of novel techniqueswhich both modify or remove the embedding medium where such stress gauges areplaced within target materials have been used to try and inform this debate. Thebehavior of three polymeric materials of differing complexity was considered,namely polystyrene, the commercially important resin transfer moulding RTM 6resin and a commercially available fat lard. Comparison to the response ofembedded gauges has suggested a possible slight decrease in the absolutemagnitude of stress. However, changing the encapsulation has no detectableeffect on the gradient behind the shock in such polymeric systems.