7500t浮式起重机金属结构的动态优化设计

摘要

采用动态子结构方法在有限元平台上建立了7500t浮式起重机的动力学模型,应用动态分层优化方法进行整体层和局部层的动态优化在整体层,实现整体结构的尺寸参数优化,提高臂架在起升平面内弯曲模态的固有频率；在局部层,实现关键子结构的截面参数优化,改善关键子结构的动刚度.通过动态优化设计,有效改善了7500t浮式起重机金属结构的动态特性,提高了其主要模态的动刚度.%By applying the dynamic substructure method,a dynamical model is constructed for the 7 500 t floating crane. Accordingly,the global and local levels are dynamically optimized using the multi-level optimization method. In the global level,the dimensional parameters of global plane are optimized to increase the jib inherent frequency of bending mode within the hoisting surface. In the local level, the cross-sectional parameters of key substructures are optimized to enhance the dynamic stiffness. Through the dynamic optimization design, the metal-structure dynamic properties of the 7 500 t floating crane is effectively improved so as to promote the dynamic stiffness of the major modes.