Abstract Ship construction involves the assembly of several blocks on a dock. When a block is lifted using a crane, it undergoes deformation. Until now, structural analysis has been applied in a few cases to evaluate the stress on such blocks. Therefore, this study proposes an evaluation method for time-domain stress using 2D flexible multibody dynamics. We adopt the discrete Euler-Lagrange equation to achieve robustness during the numerical integration of problems that involve high stiffness. We formulate the equations of motion of 2D shell elements based on the absolute nodal coordinate formulation, which is an efficient analysis technique for nonlinear and large deformation cases. We also derive the two types of kinematic constraints (ball and fixed joints) between the rigid and shell element, which can be attached to an arbitrary point. Based on the theories, we develop the program to build models, including 2D flexible multibody dynamics and several joints, and to solve the equations of motion efficiently. As a result, it is successfully applied to the dynamic analysis of the block turnover by a gantry crane and the block lifting by a floating crane. The von-Mises stresses that change over time are compared to the maximum yield stress and analyzed according to the wave direction.

中文翻译：

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使用二维柔性多体动力学进行块翻转和提升过程中的时域结构分析

摘要 船舶建造涉及在码头上组装若干块。当使用起重机吊起一个块时，它会发生变形。到目前为止，结构分析已在少数情况下用于评估此类砌块上的应力。因此，本研究提出了一种使用二维柔性多体动力学的时域应力评估方法。我们采用离散 Euler-Lagrange 方程在涉及高刚度的问题的数值积分过程中实现稳健性。我们基于绝对节点坐标公式来制定二维壳单元的运动方程，这是一种适用于非线性和大变形情况的有效分析技术。我们还推导出刚性单元和壳单元之间的两种运动学约束（球关节和固定关节），它们可以附加到任意点。基于这些理论，我们开发了程序来构建模型，包括二维柔性多体动力学和多个关节，并有效地求解运动方程。成功应用于龙门吊砌块翻转和浮吊起吊砌块的动力学分析。将随时间变化的 von-Mises 应力与最大屈服应力进行比较，并根据波浪方向进行分析。