文章通过对民用飞机在进近阶段的噪声级进行预测,为民用飞机进近阶段的噪声级的适航合格审定提供技术支持。使用控制变量法,导出飞机进近噪声水平的算法,同时利用现有机型的公开数据,对此算法进行验证,得到其有效性。基于Microsoft Visu...文章通过对民用飞机在进近阶段的噪声级进行预测,为民用飞机进近阶段的噪声级的适航合格审定提供技术支持。使用控制变量法,导出飞机进近噪声水平的算法,同时利用现有机型的公开数据,对此算法进行验证,得到其有效性。基于Microsoft Visual Studio 2010平台开发了一种算法程序来检测民用飞机的进近噪声水平,并将系统的检测结果与ESEA官网查询的数据进行比较,用以验证算法程序的有效性。结合新机型的参数数据,输入系统并得到其进近噪声级,将此数据与当前国际民航组织要求的最严格的进近噪声级相比较,判断新机型的噪声级是否满足适航要求,旨在降低民用飞机噪声合格审定成本,给飞机的设计和改进提供参考。展开更多
A process design approach for multi-stage stretch forming was proposed by combining the strain distribution method and finite element method(FEM)to determine the minimum stage number and deformation amount of each sta...A process design approach for multi-stage stretch forming was proposed by combining the strain distribution method and finite element method(FEM)to determine the minimum stage number and deformation amount of each stage.The strain distribution method was used to calculate the deformation amount of each stage and evaluate the formability through a safety criterion.FE simulation was taken as an analysis tool to reveal the deformation behaviour,to predict the strain contour and to determine the process parameters at each stage.To evaluate the effect of heat treatment after pre-strain on occurrence of deformation defects during the subsequent deformation,a multi-stage uniaxial tension test for 2B06 aluminium alloy sheet was carried out.A case study demonstrates that the approach has high reliability and good practicability.展开更多
文摘文章通过对民用飞机在进近阶段的噪声级进行预测,为民用飞机进近阶段的噪声级的适航合格审定提供技术支持。使用控制变量法,导出飞机进近噪声水平的算法,同时利用现有机型的公开数据,对此算法进行验证,得到其有效性。基于Microsoft Visual Studio 2010平台开发了一种算法程序来检测民用飞机的进近噪声水平,并将系统的检测结果与ESEA官网查询的数据进行比较,用以验证算法程序的有效性。结合新机型的参数数据,输入系统并得到其进近噪声级,将此数据与当前国际民航组织要求的最严格的进近噪声级相比较,判断新机型的噪声级是否满足适航要求,旨在降低民用飞机噪声合格审定成本,给飞机的设计和改进提供参考。
基金Project(2006AA04Z143) supported by the National High-tech Research and Development Program of ChinaProject(2006BAF04B00) supported by the National Key Technologies R&D Program of ChinaProject(2007ZE51055) supported by the Aviation Science Foundation of China
文摘A process design approach for multi-stage stretch forming was proposed by combining the strain distribution method and finite element method(FEM)to determine the minimum stage number and deformation amount of each stage.The strain distribution method was used to calculate the deformation amount of each stage and evaluate the formability through a safety criterion.FE simulation was taken as an analysis tool to reveal the deformation behaviour,to predict the strain contour and to determine the process parameters at each stage.To evaluate the effect of heat treatment after pre-strain on occurrence of deformation defects during the subsequent deformation,a multi-stage uniaxial tension test for 2B06 aluminium alloy sheet was carried out.A case study demonstrates that the approach has high reliability and good practicability.
