浅谈直升机适坠性设计

本文介绍了直升机适坠性设计的发展现状以及直升机适坠性设计的考虑因素和标准撞击状态。     

水泥基材料的准静态耐压强度

对影响水泥基材料动态耐压强度的因素进行了分析,依据水泥基材料的动态压缩强度公式,绘制了静态和动态载荷下的试验数据图,并对其进行了深入研究,得出了一些有应用价值的结论。     

Collapse analysis of real RC spatial structures using known failure schemes of ferro‐cement shell models

Large‐span reinforced concrete (RC) shells collapses that occurred in the last decade caused many death toll as well as significant losses to national economies. The most famous cases were the collapse of the aqua park cover in Moscow on February 2004 and the 2E terminal roof destruction at Charles de Gaulle Airport near Paris on May 2004. Following the publications of the appropriate commissions that have studied the reasons of these events, the influence of concrete creep and changes in the shell geometry on buckling of RC thin‐walled shells was not properly considered in the design. This study is focused on buckling of such shells, taking into account geometrical and physical nonlinear behaviour of compressed concrete. Other important reasons of concrete shells collapse are also analysed. The study is based on available experimental and theoretical investigations of ferro‐cement shells' models previously performed by the first author. The results of these investigations, obtained for small‐scale ferro‐cement models of thin‐walled shallow RC shells, are discussed. Behaviour of the tested models is compared with that of the above‐mentioned real shells and similar structures, which also collapsed. The critical buckling loads for the shells are obtained. It is shown that these loads are lower than the actual ones; thus, the shells buckling was unavoidable. To prevent brittle shell failure, they should be designed using other dominant failure modes that appear before the buckling. Possible failure schemes of real RC shells can be predicted using dominant failure modes obtained by laboratory testing of scaled models. Copyright © 2012 John Wiley & Sons, Ltd.     

甘河滩工业园区某厂区建筑地基的加固

通过一系列检测,查明某厂区建筑地基产生沉降变形的原因并进行治理,为在甘河滩工业园区进行工业建设提供了经验与教训。     

澳门混凝土结构设计规范探讨

对澳门混凝土设计规范和荷载规范中的混凝土、钢筋的材料特性等内容进行了探讨,并且对两种规范存在的差异指标进行了比较,指出了两者的优劣,同时举例说明了PKPM软件进行澳门工程设计时参数的设定方法,为同类工程提供了参考。     

爆炸荷载作用下钢框架结构的爆破模拟分析

利用ANSYS/LS-DYNA有限元程序研究爆炸荷载作用下钢框架结构的连续性倒塌机理,主要针对3层4跨钢框架和5层4跨钢框架结构进行爆破拆除仿真模拟,根据不同的适用条件,分别针对定向倒塌方案、原地倒塌方案、内向倒塌方案和折叠倒塌方案进行模拟分析。分析结果表明:通过合理设置结构各参数和爆破点位置,可较为准确地模拟钢框架结构的爆破拆除过程,可用于钢结构爆破工程中爆破方案的模拟预测,并根据模拟结果对方案进行优化调整,为实际爆破工程提供技术支持。     

空调负荷的神经计算法

提出了一种新的空调负荷计算方法－空调负荷神经计算法，介绍了其概念，原理及方法。     

预防模板支架失稳的安全技术措施

分析了现浇混凝土工程中模板支架失稳的原因 ,介绍了模板支架安装的设计内容以及模板支架的强度、稳定性、刚度的验算方法 ,并针对性地提出了预防模板支架失稳倒塌的安全技术措施     

地面板承载力的计算方法

采用有限元法，经过大量计算，探讨了影响地面板开裂荷载、环裂半径和极限承载力的各种因素，并得到了极限承载力等计算公式，其结果与试验数据吻合较好．     

某舰炮扬弹系统过载问题研究

扬弹系统是自动化火炮的重要组成部分,某火炮扬弹系统具有扬弹速度快、承受冲击载荷强等特点。在该扬弹系统中特别设置了防止异常冲击造成系统损坏的保险键,以往在该保险键频繁损坏后仅是简单更换。通过分析与研究该火炮扬弹系统过载和保险键剪断产生的原因,有针对性地提出技术措施与改进方案,同时根据扬弹系统传动装置工作条件恶劣的现状,探索与之相适应的保险键性能参数,恢复和保障了某火炮的使用功能,降低了扬弹系统的故障率,延长了火炮的使用寿命,为同类故障攻关提供参考。