抄録
Wide flanged rolled beams are important structural elements and are used in many engineering fields. From the standpoint of economical use of the structural element, the allowable stress is approaching close to the yield stress so that the knowledge of the residual stress in the beam is becoming of great importance to the design engineers.
A existing non-destructive method of measuring residual stress in a structural metal element, such as the X-ray method, is limited its usage in the sense that only the surface layer is surveyed. Recently, acoustoelasticity has been paid attention as a technique of non-destructive stress analysis. Acoustoelasticity, as an analogy to photoelasticity, makes use of stress-induced acoustic birefringent effect to measure the stress distribution in metallic materials. It is very attractive because we need not use a transparent plastic model as in photoelasticity.
However, much should be done before this method is established as a standard non-destructive technique of stress analysis. The most important is to separate the stress-induced birefringent effect from the texture-induced one. But for only special cases, such as axisymetric stress distribution and the case in which stress-free region is known a priori, the residual stress distribution can be evaluated non-destructively.
In this paper, the residual stress distribution was measured in a wide flanged rolled beam by use of a T-type transducer which has been developed recently and the results were compared with the conventional destructive method of residual stress measurements.
Also, the distribution of residual stress introduced in the cooling process after hot roolling was analyzed numerically and compared with the experimental results.
