A Simplified Indirect Measuring Method for the Notch Stress in a Thin Cylindrical Shell

Abstract

In this paper, a new simplified indirect measuring method (SIMM) is proposed for the notch stress of a circumferentially notched thin cylindrical shell by measuring the stresses away from the notch with the conventional strain gauges. The explicit relationships between the measurable stresses and notch-root stress in both the elastic and plastic stages are derived. A refined finite element modeling indicates that the developed measuring method for notch stress is feasible, and the measuring accuracy is satisfactory. A series of quasi-static tensile experiments were conducted, with both the strain gauges and advanced optical measuring method applied. Good agreement with the optical measuring results further confirms the validity and accuracy of the present method. Our method has the advantages of low cost, easy implementation, and independence of the environmental disturbance such that it has potential for wide applicability in both laboratory and in situ notch stress measurements, which is of great significance for the design of some important aerospace structures such as pyrotechnic separation devices.