Development to Determine The Components of Plane Stress Using Whole Diffraction Ring.

X-ray stress measuring technique is effective nondestructive tool to measure residual stresses and applied stresses in polycrystalline materials with sufficient reliability. Most popular X-ray stress measurement method is the sin^2Ψ method by which the lattice strains at the various angles of Ψ, between the normal of a diffraction plane and normal of a specimen surface, linearly depend on sin^2Ψ. The stress in the direction of Ψ-inclination is determined from strains at the various Ψ angles using theory of elasticity. The sin^2Ψ method is widely used as laboratory technique and the field measurement. In the field measurement, there is mainly a difficult case in the measurement by the sin^2Ψ method because of constraint of space for Ψ-inclination. By the way, in former time, the cos α method using flat pinhole camera containing X-ray film has been proposed. This method is that the plane stress components, σ_x,σ_y,τ_, are determined by using the whole diffraction ring obtained at only a Ψ angle according to back-reflection of X-rays. This method has the advantage that misalignment of specimen hardly influences for measured stress and that there are a little spatial constraint in measuring stress. However, the cosa method using X-ray film has a problem that measured stresses are influenced by the determination accuracy of incident X-ray position. In this study, new principle of stress measurement using whole diffraction ring was proposed. And stress analyzer based on the new method was developed. As a result, it was clarified that this analyzer enables to measure plane stress components. And this method can sufficiently contribute to study on material science and use for field stress measurement. This investigation was presented in The 7^