竹坑水库大坝安全鉴定分析

在竹坑水库大坝安全鉴定中,认真分析了该工程存在的主要问题,并针对大坝的结构稳定和渗流稳定作了详细的分析论证.     

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本文应用灰色关联分析方法,对70种不同类型和组成的钻井液,进行了两参数流变模式优选及评价。与现行方法比较的结果表明此方法与现行结果的吻合度高,并有新颖、数据要求量少、结论易于比较等优点。     

激光在塑性变形测量中的应用

本文将激光应用于云纹法，研究了缺口滚压强化后根部区域的位移场及应变分布规律。结果表明，本方法是提高塑性变形测量精度的有效手段。     

Energy absorption in splitting square metal tubes

This paper presents an investigation into the energy absorbing behaviour of axially splitting square metal tubes. Tubes 50 mm square with a variable thickness were pushed slowly against rigid pyramid shaped dies, which had various semi-angles. By pre-cutting 5 mm long slits at the four corners, the tube splits along the corners and curls outward with a certain radius at a constant force. In this energy dissipating system, there are three components: tearing energy, plastic deformation energy and frictional energy. Theoretical analysis of the three energy components is presented. Curl radius is also studied in detail. Good agreement between experiments and theory is obtained. The results show that tubes which both split and curl may be used as efficient, long stroke energy absorbing devices.     

Effect of thermomechanical treatment on mechanical properties and electrical conductivity of a CuCrZr alloy

The CuCrZr alloy undergoes processes of precipitation during ageing. Besides precipitation hardening the strength is affected by cold deformation which is performed before and after ageing. The cold deformation (D ₁) before ageing accelerates the process of strength hardening, since it induces higher rate of precipitation from the saturated a-sold solution. Cold deformation (D ₂) after ageing primarily affects the alloy strength. In this paper the results of the effect of thermomechanical treatment on mechanical properties and electrical conductivity of a CuCrZr alloy are presented. The aim of the paper was to evaluate the most suitable combination of thermomechanical treatment and alloy properties.     

粘弹性圆柱壳在轴向恒压下的动力稳定性

基于Timoshenko-Mindlin假设,得到考虑粘弹性的各向同性圆柱壳及纤维增强正交铺设层合圆柱壳在轴向恒压下的动力学方程。文中对两端简支的圆柱壳进行了分析,依Laplace变换,导出动力稳定的特征方程,由Routh-Hurwitz判据建立动力稳定性条件,对两类圆柱壳讨论了横向剪切变形的影响。     

一种网格结构的雷达信号处理单元

介绍了一种采用网络结构，使用五片SHARC芯片组成的相控阵雷达信号处理单元。并介绍了此单元上基于IEEE1149.1边界扫描标准的故障诊断系统。     

混凝土简支梁预设变形值探讨

以某高速公路钢筋混凝土与预应力混凝土工程为例，从简支梁的预拱度和下挠度的设置两方面进行了阐述，提出了钢筋混凝土简支梁下挠变形和预应力混凝土简支梁上拱变形的不同之处。     

某水电站溢流坝段应力应变性态分析

对某水电站溢流坝段应力应变监测资料进行了计算分析，并建立了相应的监测统计模型，从而对该坝段坝体应力应变性态作出了分析评价。     

碎丝埋弧焊在大型立式储罐中的应用

大型储罐底板焊接及变形控制是保证储罐整体施工质量的关键环节,采用碎丝填充的焊接方法可以防止变形,同时可以有效地避免应力集中,提高施工质量。文章介绍了碎丝埋弧焊的原理、工艺参数和焊接方法。实践证明,填充碎丝不仅是一种减小底板焊接变形的手段,同时可以充分利用焊接热能,节约焊接时间和焊剂用量,经济效益好,是一种值得推广的技术。