On Improving Thermoelastic Stress Analysis Data Near Edges of Discontinuities
The most serious stresses are often at the edges of geometric discontinuities, and thereby influencing the overall performance of a structure. Under adiabatic and reversible conditions, thermoelastic stress analysis (TSA) provides nondestructive full-field information of the first stress invariant in a cyclically loaded structure. However, TSA measurements at and near the edges of discontinuities, the regions of prime interest, are often unreliable due to the adverse influence of the surrounding ambient temperature as well as the movement associated with the cyclic loading. Moreover, TSA data at such locations are susceptible to nonadiabaticity because of high stress gradients, thus further supporting the need to predict stresses at edges. A method is presented here for correctly quantifying the often disregarded TSA data at the edges of a structure by making use of the linear elastic conditions of equilibrium and compatibility as well as applying the appropriate boundary conditions. The method is hybrid in the sense that experimental TSA data (excluding disregarded edge measurements) are combined with an analytical expression of the first stress invariant. The achieved improvement in thermoelastic data near discontinuities is demonstrated here for a tensile aluminum structure containing a central irregularly shaped cutout.
KeywordsHybrid Discontinuities Thermoelasticity Full-Field Edges
- 1.Greene RJ, Patterson EA, Rowlands RE (2008) Chapter 26: Thermoelastic stress analysis. In: Sharpe WM (ed) Handbook of experimental solid mechanics. Springer, New YorkGoogle Scholar
- 2.Stanley P, Chan WK (1987) Assessment and development of the thermoelastic technique for engineering application: four years of progress in stress analysis by thermoelastic techniques. In: Proceedings of SPIE 731, London, pp 17–25Google Scholar
- 4.Soutas-Little RW (1973) Elasticity. Dover, Mineola, NYGoogle Scholar
- 5.Samad WA (2013) Hybrid full-field stress analysis of structures containing nonconventional cutout geometries. PhD Thesis, University of Wisconsin-MadisonGoogle Scholar