Thermoelastic Stress Analysis of a Finite Structure Containing an Asymmetrical-Oriented, Arbitrarily-Shaped Hole

Abstract

Stresses, particularly those at geometric discontinuities, influence the structural integrity of engineering components. Motivated by the prevalence of complicated-shaped perforated components, the objective of this paper is to demonstrate the ability to stress analyze loaded finite members containing asymmetrical, irregularly-shaped cutouts. Recognizing the difficulties in obtaining purely theoretical or numerical solutions for these situations, the paper presents an expeditious means of experimentally stress analyzing such structures. Processing the load-induced temperature information with a series representation of a stress function provides the independent stress components reliably full-field, including on the edge of a hole. The stresses satisfy equilibrium and strains satisfy compatibility. In addition to being able to stress analyze complicated shapes using real, rather than complex variables, the technique is significant in which it smooths the recorded thermal information, is widely applicable, and requires neither differentiating the measured data nor knowing the elastic properties or external boundary conditions. The latter is extremely important since the external loading is often unknown in practice. That the approach provides the independent stresses is also significant since fatigue analyses and strength criteria typically necessitate knowing the individual components of stress. Present results are supported by those from a finite element analysis, strain gage measurements and load equilibrium.

Experimental stress analysis of an arbitrary geometry containing irregularly shaped hole

“…The studies of Samad and Rowlands and Kurunthottikkal Philip and Rowlands analysed perforated rectangular plates. Contrasted with the present analysis, those previous studies did not account for the external boundary.…”

“…Compatible with its more complicated geometry, traction‐free conditions are applied on both of the external and internal edges of the plate. Unlike with the study of Samad and Rowlands or Kurunthottikkal Philip and Rowlands, determining stresses on the external boundary includes those adjacent to the top‐applied load, P . The highly irregular geometry increases the amount of recorded TSA data employed, increased the form of the relevant stress function and substantially increases the required number of Airy coefficients.…”

“…The authors are unaware of any previous TSA of a perforated geometry, which had to specifically account for both interior and exterior edges. For example, compared with the study of Kurunthottikkal Philip and Rowlands, the present analysis involves 10 times more recorded thermal input data and over four times as many Airy coefficients, that is, 103 (present study) versus 23 coefficients…”