Research On Life Cycle Oriented Green Evaluation And Optimal Design Method Of Crane Structure

Bridge crane plays an important role in material handling industry and is widely used in warehouses,workshops,ports and other places.As the main bearing component of general bridge crane,the design of metal structure determines the performance of bridge crane,which has high value.The advanced design method can improve the environmental properties,mechanical properties and safety performance of the metal structure of the bridge crane,and reduce the impact on the environment in the complete life cycle of the bridge crane.At present,the traditional design method has some limitations on the degree of environmental impact.There is still a large research space in the field of green degree quantification an-d green design method of bridge crane metal structure.In this thesis,the following research work is carried out for the problems of low green degree and poor environmental attributes of bridge crane metal structure:(1)This thesis expounds the design method of metal structure of bridge crane,analyzes the mechanical model and load of metal structure of bridge crane,gives the check criteria of strength,stiffness and stability,improves the Seagull Optimization Algorithm combined with quantum calculation method,and it is used as an optimization tool for lightweight design and fatigue life design.(2)Aiming at the problem that it is difficult to characterize the green performance and environmental attributes of bridge crane metal structure,A visual description strategy of environmental attributes based on fuzzy mathematics is proposed This thesis expounds the selection principles of relevant green evaluation indexes,constructs a multi-level evaluation system covering target layer,criterion layer and index layer according to the selected evaluation indexes,combines AHP analytic hierarchy process with entropy weight method,gives weight values according to the importance of each level,reveals the quantitative mechanism of green degree of metal structure of bridge crane,and evaluates the environmental attribute of metal structure of bridge crane based on fuzzy comprehensive evaluation method,The corresponding green score is output to realize the conversion from qualitative to quantitative,which provides a theoretical basis for the green design of bridge crane metal structure.(3)Aiming at the problems of low utilization rate of metal structure materials of bridge crane,great impact on the environment or excellent single performance index,a green multi-objective collaborative optimization design model of metal structure of bridge crane is established.According to the importance of each sub optimization objective to the overall objective,the weight is allocated,the comprehensive evaluation function is constructed,and the output result of the comprehensive evaluation function is taken as the objective function of green optimization design.(4)Taking the 32 t / 22.5m general bridge crane metal structure of an enterprise as an engineering example,the design verification is carried out.The design results of the original design,lightweight design,fatigue life design and green optimization design are compared horizontally,and the effectiveness and feasibility of the green optimization design method are discussed and demonstrated.