Nowadays, sawdust has been widely regarded as a sand replacement material to produce sawdust concrete. This thesis uses orthogonal test to analyze the mechanical and heat preservation as well as heat insulation proper...Nowadays, sawdust has been widely regarded as a sand replacement material to produce sawdust concrete. This thesis uses orthogonal test to analyze the mechanical and heat preservation as well as heat insulation property with the sawdust replacement ratio of 0%, 3%, 5%, 7%, 10%, respectively, to get an optimal sawdust replacement ratio. Besides, it also discusses the deficiencies of this research.展开更多
In fiber laser beam welding(LBW),the selection of optimal processing parameters is challenging and plays a key role in improving the bead geometry and welding quality.This study proposes a multi-objective optimization...In fiber laser beam welding(LBW),the selection of optimal processing parameters is challenging and plays a key role in improving the bead geometry and welding quality.This study proposes a multi-objective optimization framework by combining an ensemble of metamodels(EMs)with the multi-objective artificial bee colony algorithm(MOABC)to identify the optimal welding parameters.An inverse proportional weighting method that considers the leave-one-out prediction error is presented to construct EM,which incorporates the competitive strengths of three metamodels.EM constructs the correlation between processing parameters(laser power,welding speed,and distance defocus)and bead geometries(bead width,depth of penetration,neck width,and neck depth)with average errors of 10.95%,7.04%,7.63%,and 8.62%,respectively.On the basis of EM,MOABC is employed to approximate the Pareto front,and verification experiments show that the relative errors are less than 14.67%.Furthermore,the main effect and the interaction effect of processing parameters on bead geometries are studied.Results demonstrate that the proposed EM-MOABC is effective in guiding actual fiber LBW applications.展开更多
文摘Nowadays, sawdust has been widely regarded as a sand replacement material to produce sawdust concrete. This thesis uses orthogonal test to analyze the mechanical and heat preservation as well as heat insulation property with the sawdust replacement ratio of 0%, 3%, 5%, 7%, 10%, respectively, to get an optimal sawdust replacement ratio. Besides, it also discusses the deficiencies of this research.
基金supported by the Project of International Cooperation and Exchanges NSFC(Grant No.51861165202)the National Natural Science Foundation of China(Grant Nos.51575211,51705263,51805330)the 111 Project of China(Grant No.B16019).
文摘In fiber laser beam welding(LBW),the selection of optimal processing parameters is challenging and plays a key role in improving the bead geometry and welding quality.This study proposes a multi-objective optimization framework by combining an ensemble of metamodels(EMs)with the multi-objective artificial bee colony algorithm(MOABC)to identify the optimal welding parameters.An inverse proportional weighting method that considers the leave-one-out prediction error is presented to construct EM,which incorporates the competitive strengths of three metamodels.EM constructs the correlation between processing parameters(laser power,welding speed,and distance defocus)and bead geometries(bead width,depth of penetration,neck width,and neck depth)with average errors of 10.95%,7.04%,7.63%,and 8.62%,respectively.On the basis of EM,MOABC is employed to approximate the Pareto front,and verification experiments show that the relative errors are less than 14.67%.Furthermore,the main effect and the interaction effect of processing parameters on bead geometries are studied.Results demonstrate that the proposed EM-MOABC is effective in guiding actual fiber LBW applications.
