润扬大桥桥位选择可行性研究

该文分析了润扬大桥桥位处镇扬河段的河床演变规律,对世业洲和渡口两个桥位处河势及河床的稳定性进行了研究,从河床演变、水文等方面说明了合理选择桥位的必要性。     

Application Research of Genetic Algorithm on the Whole-Spacecraft Vibration Isolation System

The objective of the whole-spacecraft vibration isolation (WSVI) system is to reduce the launch-induced dynamic loads and the quality control cost of the satellite and its components, and to increase the launch reliability by insertion of isolators between the satellite and the launch vehicle. A niche hybrid genetic algorithm (NHGA) is proposed to optimize stiffness and damping of the isolators. Through the comparison of the frequency response analysis results, it shows that the optimized WSVI system more effectively reduces spacecraft axial / lateral response due to the broadband structure-born launch environment. At the same time, the case of the whole-spacecraft vibration isolation optimization design demonstrates the efficiency and validity of the genetic algorithm.     

桥墩泡沫铝基组合防撞装置耗能机理及缓冲效果

滚石灾害严重威胁山区铁路桥墩建设及运营安全。针对现有桥墩防撞装置存在缓冲效果差、不易安装修复等不足，开展防撞装置耗能机理及缓冲效果研究，提出采用具有优良耗能缓冲性能的泡沫铝和聚氨酯材料多层组合的防撞装置。结果表明：泡沫铝和聚氨酯材料均具有稳定的变形破坏模式和较长的应力平台区，可持续稳定地吸收能量；组合结构耗能效果与缓冲材料的厚度和密度分布相关，增加泡沫铝材料厚度和密度，组合结构吸能总量增幅较大，吸能效率和吸能稳定性受组合结构中的聚氨酯材料的影响较大；防撞装置缓冲材料按上层（表层）50 mm聚氨酯、下层（底层）50 mm泡沫铝的双层结构配置，防护效果最佳。