支腿不同刚度比对门式起重机结构特性的影响

摘要

"假想铰"式刚柔支腿形式越来越多地为门式起重机所采用,特别是应用于大跨度、大吨位门式起重机.以提梁机这一类门式起重机为例,采用数值仿真方法,对两支腿不同刚度比及柔腿铰接工况门架结构的强度、刚度、稳定性和动力特性进行分析.结果表明:随着柔腿刚度的降低柔腿弯曲变形越来越明显,主梁跨中挠度不断增大,结构横向力减小;主梁跨中应力增大,结构稳定性减小;结构同阶次模态频率降低,振动方式有所改变.研究结果对此类门式起重机的柔腿设计、优化和安全施工具有指导和借鉴意义.%The rigidity-flexibility leg form of "Imaginary hinge" type is adopted for gantry crane more and more, especially used in large span and large tonnage gantry crane.Taking the girder hoisting machine of gantry crane as an example,the strength,stiffness,stability and dynamic response of the two legs structure with different stiffness ratios and flexible legs were analyzed. The results show that with the stiffness decrease of the flexible leg, bending deformation becomes more and more obvious,the midspan def lection of the main girder increases continuously,and the lateral force of the structure decreases;the midspan stress of the main girder line increases,the structure stability is reduced;the modal frequency of the same order mode is reduced and vibration mode is also changed. The research results can be used as guidance and reference for the design,optimization and safety construction of the flexible leg of gantry crane.