端头受外力的圆柱壳应力状态分析

本文采用的一般方法,同时又把势函数展为ξ的多项式,分析了整圆柱壳在几种边缘载荷作用下的应力状态,从而看出边界条件的提法、壳体长度对应力状态的影响的某些趋向.符号及一般公式L 为壳长、r 为半径、2h 为厚度;E 为弹性模量、σ为泊松比;ξ、θ为无量纲坐标,θ代表,...     

应用广义阶梯函数解变刚度超静定梁的弯曲问题

变刚度超静定梁的弯曲问题,可以近似的以受分段均布荷载(包括集中荷载、集中力偶)作用下的阶梯梁来代替.本文推广Heaviside函数{x-a}0的概念,定义一个新的函数{x-a}n,n=0,1,2…,称为广义阶梯函数,并给出{x-a}n{x-b}0的运算法则.然后将抗弯刚度的倒数1/EJ和弯矩方程M(x)都用{x-a}n来表示.代入挠曲线近似微分方程,从而建立一套适用于各类直梁弯曲问题的统一解法,并给出一般情况下挠曲线方程的通式.     

机床基础件动态特性的有限元分析

本文用有限元法研究了机床基础件的动态特性.编制了多单元动静结构分析程序,使得能够分析各种基础件和各种计算模型.提取矩阵特征对的方法采用迁移子空间迭代法,它具有效率高和精度高的优点.本程序也能在国产TQ—16计算机上求解其它类型复杂结构任意所要求的特征对.     

Applying the Generalized Step-function to Solve the Bending Problems of Nonuniform Beams with Variable Cross Section

The bending problems of nonuniform beams with variable cross-sectioncan be approximated by that of a step beam under sectionally uniform load(including both concentrated forces and couples).In this paper,the conceptof Heaviside function{x-a}~0 will be generalized,and a new function{x-a}~n,n=0,1,2……,will be defined,which may be named as a generalized stepfunction.The rules of operation will also be given to{x-a}~n{x-b}~0.Thereciprocal of the flexural of rigidity1/EJ and the bending moment M(x)can all be expressed in terms of{x-a}~n,and substituted into the differentialequation of the elastic curve of the beam respectively.Thus we mayestablish a set of unified method to solve various types of bending problemsof straight beams.The general solution of the deflection equation will begiven.     

FINITE ELEMENT STUDY OFODYNAMIC CHARACTERISTICS OF MAIN COMPONENTS OF MACHINE TOOLS

Dynamic characteristics have been studied for maincomponents of machine tools by finite element method.The multi-element static and dynamic structural ana-lysis program makes possible the analysis of main com-ponents in various computing models.The eigen pairs are solved by the transfer sub-space iterative method with the advantages of high ef-ficiency and precision.The program can be executedon the china-made computer TQ-16 and arbitrary sets ofeigen pairs for the treatment of dynamic characteris-tics of complex structures of various kinds are thusobtained.     

任意四边形截面直杆扭转问题的简易解法

本文采用一个简单的映射变换,将任意四边形映射为正方形,利用文[2]的结果,得到任意四边形截面直杆扭转的一种简单的半解析解法。     

Applying the generalized step-function to solve the bending problems of nonuniform beams with variable cross section

The bending problems of nonuniform beams with variable cross-section can be approximated by that of a step beam under sectionally uniform load (including both concentrated forces and couples). In this paper, the concept of Heaviside function {x-a}⁰ will be generalized, and a new function {x-a}⁰, n=0,1,2…,will be defined, which may be named as a generalized step function. The rules of operation will also be given to {x-a}ⁿ{x-b}⁰. The reciprocal of the flexural of rigidity 1/EJ and the bending moment M(x) can all be expressed in terms of {x-a}ⁿ,and substituted into the differential equation of the elastic curve of the beam respectively. Thus we may establish a set of unified method to solve various types of bending problems of straight beams. The general solution of the deflection equation will be given.     

任意压力分布下活塞环自由形状的解析解

活塞环是内燃机中重要零件.活塞环接触压力分布与相应的自由形状之间关系,已有多种理论论述,这些理论均采用特定压力分布假定.本文从薄圆环弯曲的基本微分方程出发,推导了在任意压力分布时活塞环自由形状,且编制了相应计算程序,对设计制造新型活塞环有指导意义.