Integral behavior of X-ray stress measurement

It is shown that in the X-ray-sine-squared-psi method of measuring internal stresses, the nonlinear strain distribution which is often measured is numerically related to the stress distribution, which is variable and inclined toward the surface. The calculation of the internal stresses and their parameters is based on the solution of trigonometric polynomials in the variable psi and certain integrals. The penetration depth of the X-ray beam must be known. A computer program for general numerical solution is given.