大长细比伸缩臂的非线性位移相似关系研究

Study on the Similarity Relationship of Nonlinear Displacement of Large Slender Telescopic Boom

为了加强伸缩臂设计方面的继承性,实现系列化设计。先分析了大长细比伸缩臂的受力情况,将臂架分别落到变幅平面和回转平面内研究,在变幅平面内把伸缩臂简化成一个变截面外伸梁模型,在回转平面内简化成一个变截面悬臂梁模型。并依据大位移理论描述其位移,结合方程分析法推导伸缩臂各项参数的相似比约束关系式,以量纲分析法推导的相似准则作为补充推导伸缩臂单元位移相似关系式,以单元位移相似关系替换有限单元法中形函数,计算得到伸缩臂整体位移相似关系。最后,以4组实验模型各自进行4种工况下关键位置的位移测试,选取不同实验模型和不同载荷情况下实验所得的位移数据分别进行共计40组的对比分析。结果表明:研究所得的相似关系式能够较准确地描述伸缩臂位移的关系。

In order to strengthen the inheritance of the design of the telescopic arm,achieve the systematized design.Firstly,the force of the large slender arm telescopic arm is analyzed.The boom is dropped into the variable plane and the plane of revolution.The telescopic arm is simplified into a variable cross-section beam model in the plane of revolution.The inside is simplified into a variable cross section cantilever beam model.And describe its displacement based on the large displacement theory,deduce the similarity ratio constraint relation of various parameters of telescopic arm by combining equation analysis,View the similarity criterion derived by the dimensional analysis method as a supplement to derive the displacement similarity relation of the telescopic arm unit,and the shape function of finite element method was replaced by the unit displacement similarity relationship,and obtain the similarity of the overall displacement of the telescopic arm.Finally,the displacement test of key positions under four working conditions was carried out in each of the four experimental models,and the displacement data obtained from experiments under different experimental models and different loads were compared for a total of 40 groups.The results show that the similarity relation obtained by the study can describe the relation of the displacement of telescopic arm accurately.