固有ひずみ理論に基づく未溶着部検出方法の概念提案

抄録

Some nondestructive inspection methods are used for detecting cracks. However, it is challenging to measure tightly adhered cracks such as undeposited areas in welded joints because these methods detect internal cavities. In this study, a method for identifying the geometry of a structure was developed based on the eigenstrain methodology. In the typical eigenstrain method, the three-dimensional eigenstrain distribution inducing residual stress can be estimated from surface residual stresses, elastic strains, or both when the dimensions of the structure are known. Therefore, if two out of the three factors (surface residual stresses, three-dimensional eigenstrains, and dimensions) are known, the third parameter can be determined. In the proposed method, structural dimensions were estimated using the measured surface stresses and eigenstrain distributions. Sensitivity analyses were conducted to establish the relationship of the surface residual stresses applied to areas of closely packed cracks in a known weld residual stress field.