凸轮活塞式发动机的凸轮轮廓曲线设计研究

凸轮活塞式发动机的核心部件为双面空间圆柱凸轮,其轮廓曲线将影响发动机的工作性能.设计过程中移动从动件运动规律以正弦加速度曲线为例,介绍此类发动机关键部件的设计思路,并采用极坐标法建立凸轮理论轮廓曲线方程和实际轮廓曲线方程之间的关系.     

半解析法求解含轴向浅槽复合材料圆柱壳的非线性动力响应及屈曲问题

The effect of axial shallow groove on the nonlinear dynamic response and buckling of laminated cylindrical shells subjected to radial compression loading was investigated. Based on the first-order shear deformation theory （FSDT）, the nonlinear dynamic equations involving the transverse shear deformation and initial geometric imperfections were derived with the Hamilton philosophy. The axial shallow groove of the laminated composite cylindrical shell was treated as the initial geometric imperfections in the dynamic equations. A semi-analytical method of expanding displacements and loads along the circumferential direction and employing the finite difference method along the axial direction and in the time domain is used to solve the governing equations and obtain the dynamic response of the laminated shell. The B-R criterion was employed to determine the critical loads of dynamic buckling of the shell. The effects of the parameters of the shallow groove on the dynamic response and buckling were discussed in this paper and the results show that the axial shallow grooves greatly affect the dynamic response and buckling.     

圆柱筒结构厚度的可行性计算

圆柱筒结构经常运用于各种建筑中,研究圆柱筒结构厚度的失效模式,建立圆柱筒结构强度失效的失效状态函数,用直接积分法对圆柱筒结构的可行性进行分析与研究。文章的研究为圆柱筒结构的设计、制造提供了理论参考,其方法可以应用于建筑、化工、船舶等许多领域。     

带有扰动项的3D Euler方程

本文主要研究了加一项扰动项EU后的三维欧拉方程情况.通过借助于柱坐标变换,讨论在有旋的情形下,方程组有轴对称解的务件,并得到一个新的结果.     

关于圆柱螺线性质的一些探讨

通过对一般曲线的切向量的球面像的曲率和挠率的计算,得出了圆柱螺线的三个基本向量的球面像都是球面上的平面曲线,并且是圆弧的结论.用不同的方法证明了圆柱螺线是它所在圆柱面上的测地线.说明了圆柱螺线是Bertrand曲线,同时曲率和挠率都是常数的空间曲线一定是圆柱螺线.     

Fault diagnosis of cylindrical grinding machine

Based on experiment modal analysis(EMA) and operation modal analysis(OMA), the dynamic characteristics of cylindrical grinding machine were measured and provided a basis for further failure analysis.The influences of grinding parameters on dynamic characteristics were studied by analyzing the diagnostic signals extracted from racing and grinding experiments.The significant frequency of 38 Hz related to grinding wheel spindle speed of 2 307 r/min showed that the wheel spindle system was in a state of imbalan...     

无限长通电直螺线管内、外的磁感应强度

把无限长通电直螺线管等效为由电流均匀分布圆筒及同轴圆环电流两部分组成,根据毕—奥萨伐尔定律及安培环路定理,推导出无限长通电直螺线管的磁感应强度的表达式,利用M atlab软件给出磁感应强度的数值解。结果表明,无限长通电直螺线管内部的磁感应强度分布均匀,而外部的磁感应强度并不为零。     

用柱面坐标系求解傅科摆运动

用柱面坐标系对傅科摆进行定量求解, 简明扼要, 结论直观,避免了有关文献中用复数或坐标变换求解的繁琐计算.     

基于AutoCAD渐开线圆柱齿轮的三维建模

渐开线圆柱齿轮三维建模的重点和难点在于轮齿端面轮廓的绘制。以AutoCAD为平台,根据渐开线的形成特点,介绍了修剪切线法绘制渐开线齿廓的具体步骤,利用镜像、阵列、面域、拉伸、差集、交集等命令,阐述了渐开线直齿圆柱齿轮的三维建模方法。     

柱面螺线的一般方程

通过分析给出了柱面螺线的一般方程.若柱面螺线的挠率中心轨迹是它的副法线曲面上的渐近线,我们得到该柱面螺线的一般方程.