东江扩机水电站上水库进（出）水口门槽结构有限元计算

门槽结构是进（出）水口应力状况较为复杂的关键受力部位，文章对上水库进（出）水口结构分别采用平面有限元和三维有限元方法进行了计算分析，比较详细地介绍了上水库进（出）水口门槽结构的两种方法的计算结果，并对两种算法进行了比较分析。结合结构体型和所承担荷载的特点提出了门槽配筋，并对此次计算作了总结。     

随机振动试验仿真技术研究

在对电动振动台进行刚体建模与物理参数建模的基础上,结合试验件的有限元模型进行随机振动试验仿真技术的研究.基于试验所测的振动台空台频响函数,由振动台数学参数模型辨识出振动台的物理参数,以建立能反映振动台动态特性的刚体与物理参数相结合的模型.然后,采用Craig-Bampton方法建立试验件的振动试验仿真模型,综合随机振动...     

涡轮盘结构模态分析

某火箭发动机涡轮盘在热试车中出现严重的裂纹故障,为确定故障原因,分析涡轮盘在高温及高转速下的模态特性.对比热试车涡轮泵试验数据,分析结果表明,改进前结构存在与转速6倍频耦合的涡轮盘模态,而改进后结构明显避开了耦合模态.同时,分析结果为后续结构动态响应研究提供准确的输入数据.     

向家坝水电站无岩台岩壁梁设计

文章针对向家坝水电站地下厂房尾水闸门室内的无岩台岩壁梁结构,采用关沛文法进行结构计算,并采用平面有限元法进行复核计算,对两种方法的计算结果进行比对,以印证关沛文法的假定是否符合实际受力情况。     

涡轮盘疲劳裂纹故障分析

火箭发动机涡轮盘工作在高温、高转速及恶劣的振动环境中，并承受着较大气动力作用，是发动机的关键组合件，涡轮盘的失效破坏将严重影响发动机的正常工作，甚至带来灾难性的后果。针对某火箭发动机涡轮盘在热试车中出现的裂纹故障，进行全面的分析，准确定位故障类型，以试验和计算分析给出合理的故障原因，重点是在疲劳分析方面所做的工作，包括振动模拟试验、疲劳强度计算，并根据疲劳强度分析结果提出改进方案。结果表明原结构圆角处应力集中明显，静态应力值水平高，在发生耦合振动后，涡轮盘出现疲劳裂纹，最终发生低周大应力破坏。试验和计算表明，采用改进方案可有效降低尺圆角处的应力集中，明显提高疲劳强度。对采用改进方案后的涡轮盘发动机进行了多次热试车，证实改进后的结构未发生耦合振动，未发现疲劳裂纹，改进方案是可行的。     

Numerical and Experimental Investigation of Electron Beam Air Plasma Properties at Moderate Pressure简

Large size of air plasma at near atmospheric pressure has specific effects in aerospace applications. In this paper, a two dimensional multi-fluid model coupled with Monte Carlo （MC） model is established, and some experiments were carried out to investigate the characteristics of electron beam air plasma at pressure of 100-170 Torr. Based on the model, the properties of electron beam air plasma are acquired. The electron density is of the order of 1016 m-3 and the longitudinal size can exceed 1.2 m. The profiles of charged particles demonstrate that the oxygen molecule is very important for air plasma and its elementary processes play a key role in plasma equilibrium processes. The potential is almost negative and a very low potential belt is observed at the edge of plasma acting as a protection shell. A series of experiments were carried out in a low pressure vacuum facility and the beam plasma densities were diagnosed. The experimental results demonstrate that electron density increased with the electron beam energy, and the relatively low pressure was favorable for gaining high density plasma. Hence in order to achieve high density and large size plasma, it requires the researchers to choose proper discharge parameters.     

Numerical Simulation of the Self-Heating Effect Induced by Electron Beam Plasma in Atmosphere

For exploiting advantages of electron beam air plasma in some unusual applications,a Monte Carlo(MC) model coupled with heat transfer model is established to simulate the characteristics of electron beam air plasma by considering the self-heating effect.Based on the model,the electron beam induced temperature field and the related plasma properties are investigated.The results indicate that a nonuniform temperature field is formed in the electron beam plasma region and the average temperature is of the order of 600 K.Moreover,much larger volume pear-shaped electron beam plasma is produced in hot state rather than in cold state.The beam ranges can,with beam energies of 75 keV and 80 keV,exceed 1.0 m and 1.2 m in air at pressure of 100 torr,respectively.Finally,a well verified formula is obtained for calculating the range of high energy electron beam in atmosphere.