Non-destructive natural stress detection by ultrasound - using min. transit times of two orthogonal, polarised, transversal waves and measuring associated absorption coefft.

摘要

The natural stresses in materials are non-destructively detected by a method using ultra-sound. The min. transit time of a linearly polarised transversed wave and the maximum transit time of a transversal wave, polarised orthogonally to the first one, are measured in a Cartesian coordinate system. The measurement considers also the propagation direction and the oscillation direction of the waves. The method also measures associated absorption coefficients, while the relative differences of indices are given by a computer. Tensile tests are used to provide the respective associated proportionality constants. The tensile differences are derived from specified equations for homogeneous materials free of texture and anisotropy. For other instances only the second equation is used.