大型造船龙门起重机主梁缩尺模型研究

Study on scale model for main girder of large shipbuilding gantry crane

以某船厂在役超过50年的大型造船龙门起重机主梁为研究对象,以相似三定理为理论基础的经典相似理论为依据,通过采用量纲分析法确定主梁缩尺模型的相似准则并求解出各相似比。为保证缩尺模型的合理性与可实现性,对因内侧含有不同类型加强筋而截面形式复杂的主梁,利用经典力学公式对其关键参数截面惯性矩进行等效简化计算,并以此计算缩尺模型截面参数。最后,通过有限元数值仿真验证了缩尺模型替代原主梁进行试验的合理性,为类似薄壁大截面箱形结构件的缩尺物理实验模型的建立提供了参考。

The study is about the main girder of a large shipbuilding gantry crane that has been in service for more than 50 years in a shipyard under the guidance of three similarity theorems based classic similarity theory.Dimension analysis method is used to determine similarity criteria of the scale model as well as calculating similarity ratio.Moreover,to build a rational and feasible scale model for the main girder with complex cross-section due to different types of stiffeners inside,classic mechanical formulas are used for equivalent simplified calculation of its key parameter--moment of inertia of cross-section,and cross-sectional parameters of the scale model are calculated based on this.The paper ends with proving the rationality of replacing the original main girder with the scale model through finite element numerical simulation.The study will be very helpful for establishing scaled physical experimental model for similar thin-wall box-shaped structure with large cross-section.