Since the complex impeller structure and the difficult remanufacturing process may easily cause advance remanufacturing or excessive use,an optimized design method of impeller and service mapping model was presented f...Since the complex impeller structure and the difficult remanufacturing process may easily cause advance remanufacturing or excessive use,an optimized design method of impeller and service mapping model was presented for its proactive remanufacturing with setting up to explore the best remanufacturing time point in this work.Considering a certain model of long distance pipeline compressor impeller with the Basquin equation and the design method of impeller,the mathematical relationship between the changes of structure and life of the impeller was established.And the service mapping model between the structure and life was set up and simulated by ANSYS software.Thus,the service mapping model was applied to feedback the original design for proactive remanufacturing.In this work,the best proactive remanufacturing time point of impeller was analyzed with the service mapping model,and the structural parameter values could be optimized at this time point.Meanwhile,in the results of this simulation,it proves that the impeller under this optimization performance could satisfy the impeller operating demands.Therefore,comparing with the traditional optimization design method,the remanufacturing optimized design based on the service mapping model is feasible in proactive remanufacturing for sustainable development.展开更多
The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial d...The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial distribution of background seismic activity and induct a uniform seismotectonic model for each seismotectonic region. Based on achievements of determining potential seismic sources in southwestern China,this paper introduces the basic characteristics, historical earthquakes magnitude and frequency distribution,identification of deformation mechanism of main active tectonic structures for the Longmenshan and Chengdu seismotectonic region in the Longmenshan seismic region,establishes the seismogenic model for each seismotectonic region,and identifies the upper limit of background earthquakes. A simple method is also put forward for calculating the spatial distribution function of a background seismic source.展开更多
With the level of short-circuit current of power systems growing increasingly higher,optimal allocation of current limiters has received considerable attention in recent years,especially in China.This paper analyzes t...With the level of short-circuit current of power systems growing increasingly higher,optimal allocation of current limiters has received considerable attention in recent years,especially in China.This paper analyzes two kinds of common used current limiters based on the increment of bus impedance matrix and proposes a multi-objective current limiters configuration model considering the investment of limiters,the level of short-circuit current,as well as the transient stability of power system.An innovative search space reduction technique based on sensitivity factor is introduced to choose better candidate locations for current limiters so as to avoid the curse of dimensionality.The elitist non-dominated sorting genetic algorithm II is used to search the Pareto-optimal solutions of the proposed model.In order to further improve optimization efficiency,master-slave parallel modification of NSGA-II program structure is implemented.The satisfactory case study results demonstrate the feasibility of the proposed multi-objective method in power system current limiters allocation associated with cost,security and stability.展开更多
By introducing the mechanical motion into the confined etchant layer technique(CELT), we have developed a promising ultraprecision machining method, termed as electrochemical mechanical micromachining(ECMM), for produ...By introducing the mechanical motion into the confined etchant layer technique(CELT), we have developed a promising ultraprecision machining method, termed as electrochemical mechanical micromachining(ECMM), for producing both regular and irregular three dimensional(3 D) microstructures. It was found that there was a dramatic coupling effect between the confined etching process and the slow-rate mechanical motion because of the concentration distribution of electrogenerated etchant caused by the latter. In this article, the coupling effect was investigated systemically by comparing the etchant diffusion, etching depths and profiles in the non-confined and confined machining modes. A two-dimensional(2 D) numerical simulation model was proposed to analyze the diffusion variations during the ECMM process, which is well verified by the machining experiments. The results showed that, in the confined machining mode, both the machining resolution and the perpendicularity tolerance of side faces were improved effectively. Furthermore, the theoretical modeling and numerical simulations were proved valuable to optimize the technical parameters of the ECMM process.展开更多
基金Project(2011CB013406)supported by National Basic Research Program of ChinaProjects(51305119,51375133)supported by National Natural Science Foundation of China
文摘Since the complex impeller structure and the difficult remanufacturing process may easily cause advance remanufacturing or excessive use,an optimized design method of impeller and service mapping model was presented for its proactive remanufacturing with setting up to explore the best remanufacturing time point in this work.Considering a certain model of long distance pipeline compressor impeller with the Basquin equation and the design method of impeller,the mathematical relationship between the changes of structure and life of the impeller was established.And the service mapping model between the structure and life was set up and simulated by ANSYS software.Thus,the service mapping model was applied to feedback the original design for proactive remanufacturing.In this work,the best proactive remanufacturing time point of impeller was analyzed with the service mapping model,and the structural parameter values could be optimized at this time point.Meanwhile,in the results of this simulation,it proves that the impeller under this optimization performance could satisfy the impeller operating demands.Therefore,comparing with the traditional optimization design method,the remanufacturing optimized design based on the service mapping model is feasible in proactive remanufacturing for sustainable development.
基金sponsored by the Study on the Determination of the Seismicity Parameters of Background Source-A Case Study of the Longmenshan Seismic Statistical Zone,Earthquake Administration of Sichuan Province
文摘The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial distribution of background seismic activity and induct a uniform seismotectonic model for each seismotectonic region. Based on achievements of determining potential seismic sources in southwestern China,this paper introduces the basic characteristics, historical earthquakes magnitude and frequency distribution,identification of deformation mechanism of main active tectonic structures for the Longmenshan and Chengdu seismotectonic region in the Longmenshan seismic region,establishes the seismogenic model for each seismotectonic region,and identifies the upper limit of background earthquakes. A simple method is also put forward for calculating the spatial distribution function of a background seismic source.
文摘With the level of short-circuit current of power systems growing increasingly higher,optimal allocation of current limiters has received considerable attention in recent years,especially in China.This paper analyzes two kinds of common used current limiters based on the increment of bus impedance matrix and proposes a multi-objective current limiters configuration model considering the investment of limiters,the level of short-circuit current,as well as the transient stability of power system.An innovative search space reduction technique based on sensitivity factor is introduced to choose better candidate locations for current limiters so as to avoid the curse of dimensionality.The elitist non-dominated sorting genetic algorithm II is used to search the Pareto-optimal solutions of the proposed model.In order to further improve optimization efficiency,master-slave parallel modification of NSGA-II program structure is implemented.The satisfactory case study results demonstrate the feasibility of the proposed multi-objective method in power system current limiters allocation associated with cost,security and stability.
基金supported by the National Natural Science Foundation of China (21573054, 21327002, 91323303, 21621091)the Joint Funds Key Project of the National Natural Science Foundation of China (U1537214)+2 种基金the State Key Program of National Natural Science of China (51535003)Self-Planned Task (SKLRS201606B) of State Key Laboratory of Robotics and System (HIT)the Open Project of the State Key Laboratory for Manufacturing Systems Engineering (Xi'an Jiaotong University)
文摘By introducing the mechanical motion into the confined etchant layer technique(CELT), we have developed a promising ultraprecision machining method, termed as electrochemical mechanical micromachining(ECMM), for producing both regular and irregular three dimensional(3 D) microstructures. It was found that there was a dramatic coupling effect between the confined etching process and the slow-rate mechanical motion because of the concentration distribution of electrogenerated etchant caused by the latter. In this article, the coupling effect was investigated systemically by comparing the etchant diffusion, etching depths and profiles in the non-confined and confined machining modes. A two-dimensional(2 D) numerical simulation model was proposed to analyze the diffusion variations during the ECMM process, which is well verified by the machining experiments. The results showed that, in the confined machining mode, both the machining resolution and the perpendicularity tolerance of side faces were improved effectively. Furthermore, the theoretical modeling and numerical simulations were proved valuable to optimize the technical parameters of the ECMM process.