散乱光法によるねじりを受けるポリエステルのひずみ速度の影響を考慮した光粘弾塑性解析法

抄録

Three-dimensional photovisco-elasto-plastic analysis considering strain rate effect was investigated by a scattered-light method using polyester as a model material. In order to examine the mechanical and optical properties of polyester, torsion tests were carried out on solid shafts under various twisting rates at 30°C and the effects of strain rate on the shearing stress, shearing strain, fringe gradient and increasing rate of fringe gradient were investigated. Regardless of the strain rate, it was found that the shearing stress-strain relation can be expressed by a Ramberg-Osgood equation and the fringe gradient-shearing strain relation was successfully represented by a nondimensional equation. Finally, the relation between the fringe gradient and its increasing rate was formulated as a function of strain rate. From these results, we established a method to estimate the shearing stress and the shearing strain in a three-dimensional model only by measuring the finge gradient and its increasing rate. The calculated torques from the shearing stress estimated by this photovisco-elasto-plastic analysis were consistent with the applied torques on solid and hollow shafts.