在阐述了各国抗震设计规范对钢筋混凝土结构抗震设计使用的“地震力设计法”(force based design)及其所含的评价结构抗震能力的“设计地震力 -延性”联合准则的基础上 ,说明了不能单纯用对比同样设防烈度地面运动峰值加速度条件下设计...在阐述了各国抗震设计规范对钢筋混凝土结构抗震设计使用的“地震力设计法”(force based design)及其所含的评价结构抗震能力的“设计地震力 -延性”联合准则的基础上 ,说明了不能单纯用对比同样设防烈度地面运动峰值加速度条件下设计地震力取值的高低来评价不同抗震设计规范的安全水准。在对新西兰、欧洲共同体、美国、日本和我国抗震设计规范关于钢筋混凝土结构的设计地震力取值原则以及延性要求作了评述和对比后 ,对我国钢筋混凝土结构抗震设计的安全状况作出了评价。展开更多
In this paper, the operating conditions, technical requirements, performance characteristics, design ideas, application experiences and development trends of aerospace engine bearings, including material technology, i...In this paper, the operating conditions, technical requirements, performance characteristics, design ideas, application experiences and development trends of aerospace engine bearings, including material technology, integration design and reliability, are reviewed. The development history of aerospace engine bearing is recalled briefly at first. Then today's material technologies and the high bearing performances of the bearings obtained through the new materials are introduced, which play important roils in the aeroengine bearing developments. The integration design ideas and practices are explained to indicate its significant advantages and importance to the aerospace engine bearings. And the reliability of the shaft-bearing system is pointed out and treated as the key requirement with goals for both engine and bearing. Finally, as it is believed that the correct design comes from practice, the pre-qualification rig testing conducted by FAG Aerospace GmbH & Co. KG is briefly illustrated as an example. All these lead to the development trends of aerospace engine bearings from different aspects.展开更多
文摘In this paper, the operating conditions, technical requirements, performance characteristics, design ideas, application experiences and development trends of aerospace engine bearings, including material technology, integration design and reliability, are reviewed. The development history of aerospace engine bearing is recalled briefly at first. Then today's material technologies and the high bearing performances of the bearings obtained through the new materials are introduced, which play important roils in the aeroengine bearing developments. The integration design ideas and practices are explained to indicate its significant advantages and importance to the aerospace engine bearings. And the reliability of the shaft-bearing system is pointed out and treated as the key requirement with goals for both engine and bearing. Finally, as it is believed that the correct design comes from practice, the pre-qualification rig testing conducted by FAG Aerospace GmbH & Co. KG is briefly illustrated as an example. All these lead to the development trends of aerospace engine bearings from different aspects.