Topology Optimization And Serialization Design Of Bridge-type Crane Girder

Bridge-type crane is a commonly used production and construction machinery product in China.As its main load bearing component,the girder occupies a large portion of crane weight.Under the premise of ensuring the structural safety,the proper reduction of the girder weight can effectively save the enterprise’s production costs and steel resources.In this paper,the girder structure of 32t/25.5m bridge-type crane,produced by a domestic enterprise is taken as the research object.The topology optimization method and similarity theory are combined.The topology optimization and series design of the prototype girder are carried out,and a series of new girder are obtained and verified by finite element analysis.This thesis has done the following work:1.According to the basic structure of the girder of the 32t/25.5m bridge-type crane,the load calculation is carried out based on the limit state method for the girder.The parameterized model of the girder is established in HyperMesh.Finally,the finite element calculation of the bridge-type crane’s girder is performed with five typical working conditions,and the distributions of stress and deformation of girder are obtained under the limit state.2.With the minimum compliance of five typical working conditions as the objective function,combined with SIMP variable density method and compromise optimization method,the topology optimization model of the bridge-type crane biasrail box girder is established.After the finite element analysis,the topographic structure of the girder is obtained with satisfying the loads of five typical working conditions.Considering manufacturing process,the reconstruction of girder is determined with optimal load-bearing structure,and the new hole-type web of the girder structure is designed.3.Based on the 32t/25.5m crane with new hole-type web of girder structure,the similar design method is used to analyze the relationship between the size parameters and the load of the girder.Considering key dimensions for the middle section and the square hole above the web of the girder,it is expanded to the span and the rated lifting capacity,and a series of 20t/19.5m and 50t/31.5m bridge-type cranes in which the girders were optimized by topology are obtained.The finite element analysis of the series girder structures is carried out and compared,and the effectiveness of the method in this thesis is verified.The research combines multi-case topology optimization and series design methods to achieve the purpose of reasonable weight reduction for the girder of the bridge-type crane,and will provide some guidance for the innovative design of the girder structure.