Devices for the experimental determination of individual stresses from thermoelastic data

Abstract

Three forms of bonded ‘gauge’ are described which can be used for the determination of separate stresses on the surface of a stressed body from thermoelastic data only, without recourse to supplementary experimental or computational techniques. The dimensions of the gauge, the gauge material and the form of bonding between the gauge and the stressed body are such that the thermoelastic signal from the gauge, in conjunction with that from the adjacent surface of the stressed body, allows the determination of the surface stresses in the stressed body in two orthogonal directions (e.g. parallel and normal to the ‘length’ direction of the gauge). The use of these gauges for the determination of the magnitudes and directions of the principal strains and stresses on the surface of the stressed body is also described.