The fatigue life of aeroengine turbine disc presents great dispersion due to the randomness of the basic variables,such as applied load,working temperature,geometrical dimensions and material properties.In order to am...The fatigue life of aeroengine turbine disc presents great dispersion due to the randomness of the basic variables,such as applied load,working temperature,geometrical dimensions and material properties.In order to ameliorate reliability analysis efficiency without loss of reliability,the distributed collaborative response surface method(DCRSM) was proposed,and its basic theories were established in this work.Considering the failure dependency among the failure modes,the distributed response surface was constructed to establish the relationship between the failure mode and the relevant random variables.Then,the failure modes were considered as the random variables of system response to obtain the distributed collaborative response surface model based on structure failure criterion.Finally,the given turbine disc structure was employed to illustrate the feasibility and validity of the presented method.Through the comparison of DCRSM,Monte Carlo method(MCM) and the traditional response surface method(RSM),the results show that the computational precision for DCRSM is more consistent with MCM than RSM,while DCRSM needs far less computing time than MCM and RSM under the same simulation conditions.Thus,DCRSM is demonstrated to be a feasible and valid approach for improving the computational efficiency of reliability analysis for aeroengine turbine disc fatigue life with multiple random variables,and has great potential value for the complicated mechanical structure with multi-component and multi-failure mode.展开更多
The original descriptive model of shear stress and shear displacement only reflects the stress deformation characteristics of plastic structural plane.The index model was revised and piecewise index model was built to...The original descriptive model of shear stress and shear displacement only reflects the stress deformation characteristics of plastic structural plane.The index model was revised and piecewise index model was built to describe the stress deformation characteristics of plastic structural plane and brittle structural plane.The relation of stress and strain to the failure mode of structural plane considering the effect of its shape was investigated,and a model which could reflect the relation between undulate angle and shear strength was built.The result indicates that structural plane presents nonlinear characteristics,specifically,the value of undulate angle,as well as corresponding shear strength,becomes larger as the normal stress decreases.展开更多
针对传统Petri网(P/T系统)无法根据后继标识确定系统失效部位的问题,采用着色Petri网(Colored Petri Net,CPN)建立动车组列控车载子系统的故障传播模型。首先,通过CPN与传统Petri网理论的对比说明采用CPN建模的可行性。其次,根据车载子...针对传统Petri网(P/T系统)无法根据后继标识确定系统失效部位的问题,采用着色Petri网(Colored Petri Net,CPN)建立动车组列控车载子系统的故障传播模型。首先,通过CPN与传统Petri网理论的对比说明采用CPN建模的可行性。其次,根据车载子系统的结构组成及工作模式建立故障树模型,并通过Petri网描述故障树逻辑门事件之间的逻辑关系,给出故障树的Petri网表示方法,建立车载子系统的P/T系统模型;进一步根据CPN理论确定托肯染色方法、权函数等模型参数,将P/T系统转化为着色网系统,并举例说明后继标识的计算规则。最后,通过与传统Petri网推理及故障识别过程的对比,证明了采用CPN分析系统故障机理的正确性及在故障识别过程中的高效性。所提方法可为车载子系统的故障识别提供一定依据。展开更多
基金Project(51335003)supported by the National Natural Science Foundation of ChinaProject(20111102110011)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘The fatigue life of aeroengine turbine disc presents great dispersion due to the randomness of the basic variables,such as applied load,working temperature,geometrical dimensions and material properties.In order to ameliorate reliability analysis efficiency without loss of reliability,the distributed collaborative response surface method(DCRSM) was proposed,and its basic theories were established in this work.Considering the failure dependency among the failure modes,the distributed response surface was constructed to establish the relationship between the failure mode and the relevant random variables.Then,the failure modes were considered as the random variables of system response to obtain the distributed collaborative response surface model based on structure failure criterion.Finally,the given turbine disc structure was employed to illustrate the feasibility and validity of the presented method.Through the comparison of DCRSM,Monte Carlo method(MCM) and the traditional response surface method(RSM),the results show that the computational precision for DCRSM is more consistent with MCM than RSM,while DCRSM needs far less computing time than MCM and RSM under the same simulation conditions.Thus,DCRSM is demonstrated to be a feasible and valid approach for improving the computational efficiency of reliability analysis for aeroengine turbine disc fatigue life with multiple random variables,and has great potential value for the complicated mechanical structure with multi-component and multi-failure mode.
基金Project(50878212) supported by National Natural Science Foundation of ChinaProject(1298011-2) supported by the Funding of Scientific Research and Technology Development Projects of Guangxi Province,China+2 种基金Project(12JJ6052) supported by Natural Science Foundation of Hunan Province,ChinaProject(kfj120402) supported Open Fund of Key Laboratory of Special Environment Road Engineering of Hunan Province(Changsha University of Science&Technology),ChinaProject(13C1010) supported by the Research Foundation of Education Bureau of Hunan Province,China
文摘The original descriptive model of shear stress and shear displacement only reflects the stress deformation characteristics of plastic structural plane.The index model was revised and piecewise index model was built to describe the stress deformation characteristics of plastic structural plane and brittle structural plane.The relation of stress and strain to the failure mode of structural plane considering the effect of its shape was investigated,and a model which could reflect the relation between undulate angle and shear strength was built.The result indicates that structural plane presents nonlinear characteristics,specifically,the value of undulate angle,as well as corresponding shear strength,becomes larger as the normal stress decreases.
文摘针对传统Petri网(P/T系统)无法根据后继标识确定系统失效部位的问题,采用着色Petri网(Colored Petri Net,CPN)建立动车组列控车载子系统的故障传播模型。首先,通过CPN与传统Petri网理论的对比说明采用CPN建模的可行性。其次,根据车载子系统的结构组成及工作模式建立故障树模型,并通过Petri网描述故障树逻辑门事件之间的逻辑关系,给出故障树的Petri网表示方法,建立车载子系统的P/T系统模型;进一步根据CPN理论确定托肯染色方法、权函数等模型参数,将P/T系统转化为着色网系统,并举例说明后继标识的计算规则。最后,通过与传统Petri网推理及故障识别过程的对比,证明了采用CPN分析系统故障机理的正确性及在故障识别过程中的高效性。所提方法可为车载子系统的故障识别提供一定依据。
