On the importance of encapsulation environment for lateral gauges

In principle, embedded wire-element lateral manganin pressure gauges allow the lateral component of stress during shock loading to be directly monitored. However, such gauges require target materials to be sectioned before insertion into an encapsulating MylarTM/epoxy layer, leading to debate over their analysis. In particular, recent computational modelling has suggested that, amongst other factors, gauge response may be linked to the nature of material flow within the encapsulation under shock loading. Here, this phenomenon was experimentally and computationally investigated by variation of the geometric environment of embedded lateral T-gauges (Vishay Micro-Measurements® type J2M-SS-580SF-025) in Tantalum (Ta) targets. In particular, inclusion of high impedance backing plates allowed restriction of encapsulation material flow under shock. Subsequent comparison to hydrocode simulations provided additional insights into lateral gauge interpretation.