<title>Experimental numerical analysis of 3D residual stress state in railroad rails by means of an oblique slicing technique</title>

Abstract

The paper proposes new experimental, mechanical, and numerical procedures for solving the problem of experimental determination of rail residual stresses. Basically it brings an idea of a new and original experimental scheme, which can be looked upon as modification and development of the established in the field and informally recognized as standard Battelle technique. The new methodology of examination, however, discontinues expensive and troublesome Meier sectioning, replacing it with oblique slicing that brings information of the residual stresses in rotated coordinate systems. Based only on transverse and oblique slice measurements a new mechanical procedure restores iteratively a full 3D stress state that was originally in the rail. Application of complex mathematical procedures like physically based approximation techniques (embodiment of physical relations into approximation equations) and a full 3D model of the continuum (finite element analysis) along with moire interferometry measurements ensures high quality final results that are mechanically consistent with the applied model of the continuum. The paper discusses in detail mechanical background of the technique, experimental procedure and algorithms of numerical data handling and enhancement. An extensive range of tests show results of an in-depth investigation into the technique that has been carried out on simulated data. Possible extensions to the technique and further research plans also are shown.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.