Given the global lack of effective analysis methods for the impact of design parameter tolerance on performance deviation in the vehicle proof-of-concept stage,it is difficult to decompose performance tolerance to des...Given the global lack of effective analysis methods for the impact of design parameter tolerance on performance deviation in the vehicle proof-of-concept stage,it is difficult to decompose performance tolerance to design parameter tolerance.This study proposes a set of consistency analysis methods for vehicle steering performance.The process of consistency analysis and control of automotive performance in the conceptual design phase is proposed for the first time.A vehicle dynamics model is constructed,and the multi-objective optimization software Isight is used to optimize the steering performance of the car.Sensitivity analysis is used to optimize the design performance value.The tolerance interval of the performance is obtained by comparing the original car performance value with the optimized value.With the help of layer-by-layer decomposition theory and interval mathematics,automotive performance tolerance has been decomposed into design parameter tolerance.Through simulation and real vehicle experiments,the validity of the consistency analysis and control method presented in this paper are verified.The decomposition from parameter tolerance to performance tolerance can be achieved at the conceptual design stage.展开更多
At present,research on hydraulic mounts has mainly focused on the prediction of the dynamic stiffness and loss angle.Compared to the traditional finite element analysis method,the programming method can be used to ana...At present,research on hydraulic mounts has mainly focused on the prediction of the dynamic stiffness and loss angle.Compared to the traditional finite element analysis method,the programming method can be used to analyze hydraulic mounts for a rapid and accurate understanding of the influence of the different mounting parameters on the dynamic stiffness and loss angle.The aims of this study were to investigate the nonlinear dynamic characteristics of a hydraulic mount,and to identify the parameters that affect the dynamic stiffness and loss angle using MATLAB software programs to obtain the influence curves of the parameters,so as to use suitable parameters as the basis for vibration analysis.A nonlinear mechanical model of a hydraulic mount was established according to the basic principles of fluid dynamics.The dynamic stiffness and loss angle of the dimensionless expression were proposed.A numerical calculation method for the dynamic performance evaluation index of the hydraulic mount was derived.A one-to-one correspondence was established between the structural parameters and peak frequency of the evaluation index.The accuracy and applicability of the mechanical model were verified by the test results.The results demonstrated the accuracy of the nonlinear mechanical model of the hydraulic mount,and the vehicle driving comfort was greatly improved by the optimization of the structural parameters.展开更多
With the development of e-commerce,manufacturers have opportunities to sell products to consumers through direct channels in addition to independent retailers.Although manufacturers’encroachment upon the retailing ma...With the development of e-commerce,manufacturers have opportunities to sell products to consumers through direct channels in addition to independent retailers.Although manufacturers’encroachment upon the retailing market of traditional goods has been extensively studied,there is a lack of research on manufacturers’encroachment in a pharmaceutical supply chain.This paper analyzes a pharmaceutical manufacturer encroachment strategy by taking into account the distinctive features of drugs,in which drug expenses are covered by medical insurance only in the physical channel and patients'channel preference is also considered.We find that under certain circumstances,the manufacturer encroachment may lead to a win-win outcome for both the manufacturer and the retailer,contradicting the conventional wisdom that the manufacturer's encroachment into retail space is detrimental to the independent retailer.Additionally,the manufacturer is more likely to encroach when the incurred extra cost is sufficiently small,the perceived quality of the drug selling through the direct channel is sufficiently high and the out-of-pocket percentage cost of the drug selling in the physical channel is high.We further study the impact of manufacturer encroachment on social welfare and find that the introduction of encroachment decreases the social welfare when patients'perceived quality of the drug obtained through the online store is low and improves the social welfare when the perceived quality exceeds a certain threshold.展开更多
文摘Given the global lack of effective analysis methods for the impact of design parameter tolerance on performance deviation in the vehicle proof-of-concept stage,it is difficult to decompose performance tolerance to design parameter tolerance.This study proposes a set of consistency analysis methods for vehicle steering performance.The process of consistency analysis and control of automotive performance in the conceptual design phase is proposed for the first time.A vehicle dynamics model is constructed,and the multi-objective optimization software Isight is used to optimize the steering performance of the car.Sensitivity analysis is used to optimize the design performance value.The tolerance interval of the performance is obtained by comparing the original car performance value with the optimized value.With the help of layer-by-layer decomposition theory and interval mathematics,automotive performance tolerance has been decomposed into design parameter tolerance.Through simulation and real vehicle experiments,the validity of the consistency analysis and control method presented in this paper are verified.The decomposition from parameter tolerance to performance tolerance can be achieved at the conceptual design stage.
文摘At present,research on hydraulic mounts has mainly focused on the prediction of the dynamic stiffness and loss angle.Compared to the traditional finite element analysis method,the programming method can be used to analyze hydraulic mounts for a rapid and accurate understanding of the influence of the different mounting parameters on the dynamic stiffness and loss angle.The aims of this study were to investigate the nonlinear dynamic characteristics of a hydraulic mount,and to identify the parameters that affect the dynamic stiffness and loss angle using MATLAB software programs to obtain the influence curves of the parameters,so as to use suitable parameters as the basis for vibration analysis.A nonlinear mechanical model of a hydraulic mount was established according to the basic principles of fluid dynamics.The dynamic stiffness and loss angle of the dimensionless expression were proposed.A numerical calculation method for the dynamic performance evaluation index of the hydraulic mount was derived.A one-to-one correspondence was established between the structural parameters and peak frequency of the evaluation index.The accuracy and applicability of the mechanical model were verified by the test results.The results demonstrated the accuracy of the nonlinear mechanical model of the hydraulic mount,and the vehicle driving comfort was greatly improved by the optimization of the structural parameters.
基金support of National Natural Science Foundation of China under Grant Nos.71771166 and 72174138and Tianjin Natural Science Foundation under Grant No.18JCQNJCO4200.
文摘With the development of e-commerce,manufacturers have opportunities to sell products to consumers through direct channels in addition to independent retailers.Although manufacturers’encroachment upon the retailing market of traditional goods has been extensively studied,there is a lack of research on manufacturers’encroachment in a pharmaceutical supply chain.This paper analyzes a pharmaceutical manufacturer encroachment strategy by taking into account the distinctive features of drugs,in which drug expenses are covered by medical insurance only in the physical channel and patients'channel preference is also considered.We find that under certain circumstances,the manufacturer encroachment may lead to a win-win outcome for both the manufacturer and the retailer,contradicting the conventional wisdom that the manufacturer's encroachment into retail space is detrimental to the independent retailer.Additionally,the manufacturer is more likely to encroach when the incurred extra cost is sufficiently small,the perceived quality of the drug selling through the direct channel is sufficiently high and the out-of-pocket percentage cost of the drug selling in the physical channel is high.We further study the impact of manufacturer encroachment on social welfare and find that the introduction of encroachment decreases the social welfare when patients'perceived quality of the drug obtained through the online store is low and improves the social welfare when the perceived quality exceeds a certain threshold.
