利用三维光弹试验探讨偏心荷载对沿螺纹紧固件根部螺旋线的应力分布的影响。在本研究中，轴向和弯曲应力的比率与那些通常在工程部门所发现的相似。结果表明，随着偏心水平的增加，在螺纹根部螺旋线上的最大应力没有较大的改变，但经受高应力的螺旋线的长度增加了。偏心荷载的存在将导致裂纹产生和扩展概率的增加。 The effect of eccentric load on the stress distribution along the helix of the threaded fastener was investigated by 3D photoelastic test. In this study, the ratio of axial to flexural stresses is similar to what is commonly found in the engineering department. The results show that as the eccentricity increases, the maximum stress on the root helix of the thread does not change much, but the length of the helical thread subjected to high stress increases. The existence of eccentric load will lead to the increase of the probability of crack generation and expansion.