Free-interface dual-compatibility modal synthesis method(compatibility of both force and displacement on interfaces)is introduced to large-scale civil engineering structure to enhance computation efficiency. The basic...Free-interface dual-compatibility modal synthesis method(compatibility of both force and displacement on interfaces)is introduced to large-scale civil engineering structure to enhance computation efficiency. The basic equations of the method are first set up, and then the mode cut-off principle and the dividing principle are proposed. MATLAB is used for simulation in different frame structures. The simulation results demonstrate the applicability of this substructure method to civil engineering structures and the correctness of the proposed mode cut-off principle. Studies are also conducted on how to divide the whole structure for better computation efficiency while maintaining better precision. It is observed that the geometry and material properties should be considered, and the synthesis results would be more precise when the inflection points of the mode shapes are taken into consideration. Furthermore, the simulation performed on a large-scale high-rise connected structure further proves the feasibility and efficiency of this modal synthesis method compared with the traditional global method. It is also concluded from the simulation results that the fewer number of DOFs in each substructure will result in better computation efficiency, but too many substructures will be time-consuming due to the tedious synthesis procedures. Moreover, the substructures with free interface will introduce errors and reduce the precision dramatically, which should be avoided.展开更多
The importance of mistuning analysis lies on understanding the vibration characteristics of the bladed disk.Previous works generally ignored the nonlinear effect of prestress,which increase the gap between the actual ...The importance of mistuning analysis lies on understanding the vibration characteristics of the bladed disk.Previous works generally ignored the nonlinear effect of prestress,which increase the gap between the actual results and research results.In this paper,a unique way to address the reduced-order model is presented,where disk and each blade component is attached as individual substructures with free-interface component mode synthesis considering prestress.The influence of nonlinear inertial effect on mistuning characteristics of rotors is compared with linear inertial effect.Results show that ignoring nonlinearity of the rotational speed,the influence of speed on mode localization may be different from the true situation.展开更多
基金Supported by the National Natural Science Foundation of China(No.51108089)Doctoral Programs Foundation of Ministry of Education of China(No.20113514120005)the Foundation of the Education Department of Fujian Province(No.JA14057)
文摘Free-interface dual-compatibility modal synthesis method(compatibility of both force and displacement on interfaces)is introduced to large-scale civil engineering structure to enhance computation efficiency. The basic equations of the method are first set up, and then the mode cut-off principle and the dividing principle are proposed. MATLAB is used for simulation in different frame structures. The simulation results demonstrate the applicability of this substructure method to civil engineering structures and the correctness of the proposed mode cut-off principle. Studies are also conducted on how to divide the whole structure for better computation efficiency while maintaining better precision. It is observed that the geometry and material properties should be considered, and the synthesis results would be more precise when the inflection points of the mode shapes are taken into consideration. Furthermore, the simulation performed on a large-scale high-rise connected structure further proves the feasibility and efficiency of this modal synthesis method compared with the traditional global method. It is also concluded from the simulation results that the fewer number of DOFs in each substructure will result in better computation efficiency, but too many substructures will be time-consuming due to the tedious synthesis procedures. Moreover, the substructures with free interface will introduce errors and reduce the precision dramatically, which should be avoided.
基金The National Natural Science Foundation of China(No.11502037)the Chongqing Research Program of Basic Research and Frontier Technology(No.cstc2018jcyj A3066)the Fundamental Research Funds for the Central Universities(No.2018CDGFHK0019)
文摘The importance of mistuning analysis lies on understanding the vibration characteristics of the bladed disk.Previous works generally ignored the nonlinear effect of prestress,which increase the gap between the actual results and research results.In this paper,a unique way to address the reduced-order model is presented,where disk and each blade component is attached as individual substructures with free-interface component mode synthesis considering prestress.The influence of nonlinear inertial effect on mistuning characteristics of rotors is compared with linear inertial effect.Results show that ignoring nonlinearity of the rotational speed,the influence of speed on mode localization may be different from the true situation.
