拉剪多轴载荷作用下的弹性梁弯曲变形

为设计海洋柔性管缆装备多轴加载试验工况,通过建立解析模型和有限元数值模型研究了弹性梁在轴向拉伸载荷与横向多集中载荷共同作用下的弯曲变形,以及拉伸载荷、横向剪力、弯曲刚度等对变形的影响规律,拟合了弹性梁跨中曲率与多轴载荷的近似关系式。结果表明：解析模型结果与有限元结果吻合较好,可见解析模型的正确性。轴向拉力使得跨中区域曲率呈现“凹”形态；梁跨中曲率随拉力增大或剪力减小而迅速减小同时曲率分布更平滑,但随弯曲刚度的下降呈现先增大后减小；拟合的弹性梁跨中曲率与多轴载荷关系式满足工程精度要求。

Bend Deformation of Elastic Beam Loaded by Axial Tension and Transverse Shearing Force

In order to determine the test loading cases for offshore flexible risers and umbilicals, an analytical model and an finite element model were used to investigate bend deformation of an elastic beam loaded by axial tension and transverse concentrated shearing forces. The influence of tension, transverse shearing fore and bend stiffness on the bend deformation was discussed. Then the relation between the curvature at the middle of beam and multiaxial loads was expressed. The results show that the results from the analytical model and the numerical model agree well, which validates the analytical model. Then, concave curvature distribution appears in the middle region of the beam induced by axial tension. The middle curvature value reduces rapidly, meanwhile the curvature distribution is more smooth, as axial tension increases or shearing forces decreases, however, first grows then falls along with bend stiffness reducing. Additionally, the fitting equation of the curvature at the middle of beam and multiaxial loads could meet requirements of engineering accuracy.