Holographic non-destructive testing (HNDT) of low modulus materials using a bending load

A holographic non-destructive testing method using mechanical loading for low modulus materials has been established in a previous work specifically applying axial compressive loading for the detection of surface, subsurface and inner voids in solid propellant blocks. As an extension a method for the detection and characterisation of cracks using tensile loading is presented in this paper. The proposed bending type of load provides both tension and compression in the component and also introduces higher stress for the same applied load compared to pure tensile load. A general methodology is proposed for the detection and characterisation of all types of defects