Studies to date have failed to consider gage disc cutters’variable cutting depth and the constraints of cutter-head welds,and have ignored the coupling mechanism between the profile of the full-face rock tunnel-borin...Studies to date have failed to consider gage disc cutters’variable cutting depth and the constraints of cutter-head welds,and have ignored the coupling mechanism between the profile of the full-face rock tunnel-boring machine(TBM)cutter-head and the assembled radius layout of the disc cutters.To solve these problems,an adaptive design method for studying cutter layout was proposed.Taking the bearing stress of the outermost gage disc cutter as an index,the profile of the cutter-head was determined.Using a genetic algorithm and based on the principles of equal life and equal wear,the assembled radii of the cutters were optimally designed.Boundary conditions of non-interference between the cutters,manholes,muck buckets and welding lines were given when a star layout pattern was used on cutters.The cutter-head comprehensive evaluation model was established by adopting relative optimization improvement degree of evaluation indices to achieve dimensional consistency.Exemplifying the MB264-311-8030 mm tape TBM cutter-head,the calculations show that compared with the original layout scheme,among the 51 disc cutters,the largest gap of the cutters’assembled radiuses is only 25.8 mm,which is 0.64%of the cutter-head’s radius and is negligible.The cutter-head’s unbalanced radial force decreases by 62.41%,the overturning moment decreases by 33.22%,and the cutter group’s centroid shift increases by only 18.48%.Each index is better than or approximately equal to the original cutter-head layout scheme,and the equivalent stress and deformation are both smaller;these results fully verify the feasibility and effectiveness of the method.展开更多
In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters ...In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters for shield cutterhead is formulated,based on the complex engineering technical requirements. In the model, as the objective function of the model is a composite function of the strength and stiffness, the response surface method is applied to formulate the approximate function of objective function in order to reduce the solution scale of optimal problem. A multi-objective genetic algorithm is used to solve the cutterhead structure design problem and the change rule of the stress-strain with various structural parameters as well as their optimal values were researched under specific geological conditions. The results show that compared with original cutterhead structure scheme, the obtained optimal scheme of the cutterhead structure can greatly improve the strength and stiffness of the cutterhead, which can be seen from the reduction of its maximum equivalent stress by 21.2%, that of its maximum deformation by 0.75%, and that of its mass by 1.04%.展开更多
基金Projects(51275339,51575379,51675374)supported by the National Natural Science Foundation of ChinaProject(2013CB035402)supported by the National Hi-tech Research and Development Program of China
文摘Studies to date have failed to consider gage disc cutters’variable cutting depth and the constraints of cutter-head welds,and have ignored the coupling mechanism between the profile of the full-face rock tunnel-boring machine(TBM)cutter-head and the assembled radius layout of the disc cutters.To solve these problems,an adaptive design method for studying cutter layout was proposed.Taking the bearing stress of the outermost gage disc cutter as an index,the profile of the cutter-head was determined.Using a genetic algorithm and based on the principles of equal life and equal wear,the assembled radii of the cutters were optimally designed.Boundary conditions of non-interference between the cutters,manholes,muck buckets and welding lines were given when a star layout pattern was used on cutters.The cutter-head comprehensive evaluation model was established by adopting relative optimization improvement degree of evaluation indices to achieve dimensional consistency.Exemplifying the MB264-311-8030 mm tape TBM cutter-head,the calculations show that compared with the original layout scheme,among the 51 disc cutters,the largest gap of the cutters’assembled radiuses is only 25.8 mm,which is 0.64%of the cutter-head’s radius and is negligible.The cutter-head’s unbalanced radial force decreases by 62.41%,the overturning moment decreases by 33.22%,and the cutter group’s centroid shift increases by only 18.48%.Each index is better than or approximately equal to the original cutter-head layout scheme,and the equivalent stress and deformation are both smaller;these results fully verify the feasibility and effectiveness of the method.
基金Project(51074180) supported by the National Natural Science Foundation of ChinaProject(2012AA041801) supported by the National High Technology Research and Development Program of China+2 种基金Project(2007CB714002) supported by the National Basic Research Program of ChinaProject(2013GK3003) supported by the Technology Support Plan of Hunan Province,ChinaProject(2010FJ1002) supported by Hunan Science and Technology Major Program,China
文摘In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters for shield cutterhead is formulated,based on the complex engineering technical requirements. In the model, as the objective function of the model is a composite function of the strength and stiffness, the response surface method is applied to formulate the approximate function of objective function in order to reduce the solution scale of optimal problem. A multi-objective genetic algorithm is used to solve the cutterhead structure design problem and the change rule of the stress-strain with various structural parameters as well as their optimal values were researched under specific geological conditions. The results show that compared with original cutterhead structure scheme, the obtained optimal scheme of the cutterhead structure can greatly improve the strength and stiffness of the cutterhead, which can be seen from the reduction of its maximum equivalent stress by 21.2%, that of its maximum deformation by 0.75%, and that of its mass by 1.04%.
