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
为探究突发公共卫生事件应急能力提升路径,基于应急管理全过程理论,遵循“分析-评价-提升”的逻辑,首先,分析突发公共卫生事件特点与发展变化规律,构建包含预防与准备、监测与预警、处置与救援、恢复与重建4项一级指标,以及23项二级指...为探究突发公共卫生事件应急能力提升路径,基于应急管理全过程理论,遵循“分析-评价-提升”的逻辑,首先,分析突发公共卫生事件特点与发展变化规律,构建包含预防与准备、监测与预警、处置与救援、恢复与重建4项一级指标,以及23项二级指标的评价指标体系;然后结合主成分分析,运用熵权TOPSIS法(Technique for Order Preference by Similarity to an Ideal Solution,TOPSIS)和秩和比法(Rank-Sum Ratio,RSR)构建应急能力评价模型;最后,分析陕西省10个地级市2018-2022年数据,得到各地级市公共卫生事件应急能力评价等级。结果表明:陕西省应急能力分布总体呈现中部高而四周低,北部较高、东南部较低的空间格局;研究期内西安市的应急能力总体表现最优,评分均在0.65以上,其次为榆林、咸阳、铜川和宝鸡;西安市应急能力较为均衡,部分地级市恢复重建能力占比仍有待提升;卫生机构覆盖率、社区卫生服务中心覆盖率和疾病预防控制中心覆盖率为影响突发公共卫生事件管控的最有效因素。研究结果为提升突发公共卫生事件的应对能力提供了一定的实践借鉴。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.
文摘为探究突发公共卫生事件应急能力提升路径,基于应急管理全过程理论,遵循“分析-评价-提升”的逻辑,首先,分析突发公共卫生事件特点与发展变化规律,构建包含预防与准备、监测与预警、处置与救援、恢复与重建4项一级指标,以及23项二级指标的评价指标体系;然后结合主成分分析,运用熵权TOPSIS法(Technique for Order Preference by Similarity to an Ideal Solution,TOPSIS)和秩和比法(Rank-Sum Ratio,RSR)构建应急能力评价模型;最后,分析陕西省10个地级市2018-2022年数据,得到各地级市公共卫生事件应急能力评价等级。结果表明:陕西省应急能力分布总体呈现中部高而四周低,北部较高、东南部较低的空间格局;研究期内西安市的应急能力总体表现最优,评分均在0.65以上,其次为榆林、咸阳、铜川和宝鸡;西安市应急能力较为均衡,部分地级市恢复重建能力占比仍有待提升;卫生机构覆盖率、社区卫生服务中心覆盖率和疾病预防控制中心覆盖率为影响突发公共卫生事件管控的最有效因素。研究结果为提升突发公共卫生事件的应对能力提供了一定的实践借鉴。
