圆柱壳小开孔理论解在工程实践中的应用

完全从一个新的角度,重新研究圆柱壳小开孔的理论解,指出了它与圆柱壳大开孔理论解之间的某一种特殊的内在联系。利用这种联系,重新估计了小开孔理论解在工程实践中的应用范围,为如何利用圆柱壳小开孔理论,提供了一种设想。对圆柱壳小开孔理论在工程实践中的应用重新做出了一个评价。     

薄壁柱壳在内部爆炸载荷下膨胀断裂的研究

以柱形爆炸装置为研究对象 ,讨论了其薄壁壳体在爆炸载荷下的动态断裂准则。给出了典型的FAE模型及在数值计算时必要的简化条件。对回收的壳壁破片进行了SEM扫描电镜观测 ,分析了金属材料在高应变率下膨胀断裂的微观机制。采用解耦的、考虑应变强化的粘塑性本构方程 ,根据损伤破坏理论推导出以临界应变为依据的改进断裂准则 ,计算表明断裂参数理论解与数值模拟结果一致 ,并得到了实验方面的例证。     

轴向冲击载荷下圆柱壳的弹塑性屈曲分析

研究时变轴向冲击载荷作用下的圆柱壳弹塑性动力屈曲问题。本构关系采用增量理论 ,借助增量数值计算方法对Karman Donnell运动方程进行求解。计算表明 :基于B R准则的屈曲判断方法和采用Southwell方法可以获得一致的临界屈曲载荷 ;分别讨论了应力波对屈曲的影响以及材料参数、几何参数、载荷峰值与持续时间和动力屈曲的关系。     

多个纵向环形界面裂纹对P波散射的动应力强度因子

研究多个纵向环形界面裂纹的Ｐ波散射问题。以裂纹面的位错密度函数为未知量,利用Ｆｏｕｒｉｅｒ积分变换,将问题归结为第二类奇异积分方程,然后通过数值求解,获得裂纹尖端的动应力强度因子。最后给出了双裂纹动应力强度因子随入射波频率变化的关系曲线。     

静力预加载环向加筋圆柱壳的轴向流-固冲击屈曲

将初缺陷放大准则应用于静力预加载环向加筋圆柱壳结构受轴向流-固冲击加载作用时的几何非线性动力屈曲研究中。运用Galerkin方法推导出壳体-肋骨系统的动力屈曲控制方程,并且采用Runge-Kutta法进行数值求解。着重分析了静力预加载荷对结构屈曲性态及抗轴向冲击能力的影响。     

Comparison of Electron-Beam-Misalignment Effect on Starting Current and Output Power in Coaxial-Cavity and Cylindrical-Cavity Gyrotron Oscillators

Comparative study is presented to the effect of the electron-beam misalignment on the starting current and output power of the coaxial-cavity and cylindrical-cavity gyrotron oscillators operating in the millimeter wave ranges. The numerical analysis is based on the gyrokinetic formulas for a TE_28,16,1 mode at a frequency of 140 GHz. Results show that the coaxial-cavity gyrotron oscillator has lower starting current and less power loss than the cylindrical-cavity gyrotron oscillator when the electron-beam axis has a misalignment to the cavity axis.     

凸柱面透镜列阵线聚焦系统

主要描述了柱面透镜列阵聚焦系统的原理及结构,分析了凹柱面透镜列阵线聚焦系统中非球面透镜损坏的原因,介绍了凸柱面透镜列阵线聚焦系统的设计原则、性能及在中日合作Ｘ射线激光实验中的使用情况     

拉载下周向壁穿裂纹圆柱壳的弹塑性解析解

基于薄壳理论及Ｄｕｇｄａｌｅ模型,建立了一套相当完整的拉载下周向壁穿裂纹圆柱壳的弹塑性解析解．该解包括裂纹扩展并可应用至裂纹断面完全塑性     

Delamination growth of laminated composite cylindrical shells

The local buckling may occur in delaminated cylindrical shells under axial compression. This often causes delamination growth and structure failure. Based on the variational principle of moving boundary, in this paper, the postbuckling governing equations for the laminated cylindrical shells are derived, and the corresponding boundary and matching conditions are given. At the same time, according to the Griffith criterion, the formulas of energy release rate along the delamination front are obtained and the delamination growth is studied. In the numerical calculation, the delamination growth of axisymmetrical laminated cylindrical shells is analyzed, and the effects of delamination sizes and depths, the boundary conditions, the material properties and the laminate stacking sequences on delamination growth are discussed.     

Scattering of Plane SH-Wave by a Cylindrical Hill of Arbitrary Shape

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