两斜交圆柱壳应力分析的边界元法

本文研究了两斜交圆柱壳的边界元法。提出了用板的基本解叠加级数形式的修正项构成圆柱壳的基本解,提高了计算精度,缩短了计算时间。对区域积分进行特殊处理,从而避免了内部网格的划分,大大减少了数据准备工作量和占机内存。并编制了FORTRAN计算程序,进行了数值计算。     

基于GPRS的GPS实时差分系统研究与实现

介绍了GPS实时差分系统基本原理及实现过程，提出了基于GPRS的GPS实时差分系统的总体结构；完成了基于GR47的GPRS数据传输模块的硬件和软件设计；实现了服务器软件数据监控及处理功能；采用无缝技术实现GPRS与Internet链接，建立了GPS差分数据传输通道；提出了通讯链路时间延迟的测试方法，分析了过大时间延迟的原因并给出了解决方案。实际测试结果表明：基于GPRS的GPS实时差分系统达到了厘米级定位精度。     

硅微机械陀螺仪的机电接口模型分析

建立了某种硅微机械陀螺仪的电路模型,分析了寄生电容对接口电路的影响.结果表明,合理的接口电路不仅消除了大部分的寄生电容的影响,而且减小了信号的衰减幅度,抑制了大部分的耦合信号和噪声信号.最后对接口电路进行了改进,除了保留以上的一些优点外,还减小了载波信号的变化和电源变化对电容分辨率的影响,提高了整个电路的分辨率.     

钢管桩固结过程的分析

本文用连续介质力学的基本理论分析了钢管桩的固结过程。采用径向固结模型进行了描述并给出了它的解析解。指出了固结过程提高了钢管桩的承载能力。     

激光多光束闸墩位移测量研究

根据实际大型工建筑测试的需要，研究激光多光束的全变位测试方法，提出了相应的计算公式，研究了制造了实用的测试装置，并对大型闸墩进行了实地测量，分析了闸体的损伤程度，作了安全评估。     

陀螺马达电源的研究

本文讨论了三相交流陀螺马达电源的工作原理。根据主要技术指标的要求，设计了陀螺马达电源，给出了该电源的各个组成部分的线路设计，解决了研制中出现的电源振荡问题，论述了该电源的设计特点，给出了使用结论     

超静定梁变形计算的有限差分法

推导了超静定梁变形计算的有限差分方程，研究了边界条件，编制了计算程序，计算 了超静定梁的变形. 文中工作扩大了有限差分法的应用范围.     

缝合复合材料层板刚度预报

提出了缝合复合材料层板的刚度预报模型,该模型考虑了缝合针脚处的孔洞对刚度的影响,描述了缝合孔洞的几何形态,建立了孔洞形态与纤维弯曲的关系,采用平均刚度法和经典层合板理论进行了刚度预报,获得了与试验数据相吻合的预报结果,表明了该模型的有效性,详细探讨了缝合孔洞对缝合层板刚度的影响规律,得到一些有益结论。     

超静定梁变形计算的有限差分法

推导了超静定梁变形计算的有限差分方程,研究了边界条件,编制了计算程序,计算了超静定梁的变形.文中工作扩大了有限差分法的应用范围.     

绿色润滑油的发展概况

概述了绿色润滑油的发展状况,阐述了绿色润滑油的含义,阐述了绿色润滑油的含义,介绍了生物降解试验方法,通过对绿色润滑油基础油及基适用的添加剂的综述,提出了绿色润滑油发展过程中存在的主要问题,并对将来的发展趋势进行了展望。     

Identification of Parameters of Short-Time Creep of Plexiglas By Means of Studying Decaying Flexural Vibrations of Test Samples

A technique for identification of hereditary properties under conditions of short-time creep of Plexiglas is developed. The technique is based on experimental determination of shifting of the center of decaying flexural vibrations of vertically aligned test samples after their preliminary maintaining in a static bent state. Mathematically, the technique is based on using the finite element method and integral equations of the theory of hereditary viscoelasticity with the Koltunov–Rzhanitsyn hereditary kernel. An object function is constructed for identification of rheological parameters of this kernel. The minimum of this function is found by the direct search method, which does not require the function gradient to be known. The hereditary kernel of Plexiglas averaged on the basis of data for several test samples is obtained as a function of time.     

Stability of anisotropic shells of revolution of positive or negative Gaussian curvature

A mixed variational principle is derived by Hamilton’s method from the principle of minimum potential energy for thin anisotropic shells of revolution and is then used to derive a normal system of equations with complex coefficients. Discrete orthogonalization is used to solve this homogeneous system and the nonlinear system of equations that describes the precritical state of shells. A shell generated by revolving a circular arc around the axis parallel to its chord is analyzed for stability. The solution is compared with the approximate solution obtained assuming that the precritical state is membrane. It is established that the approximate problem formulation gives incorrect results for shells of negative Gaussian curvature     

Integral Representations of Increments of Stochastic Processes

A formulation is presented in which the increment of a stochastic process is represented as an integral of the derivative of the process. It is shown that this representation is an alternative to the more common approach of writing equations for the differentials of stochastic processes. A possible advantage of the integral formulation is that its reliance on derivatives, rather than differentials, makes the operations of stochastic calculus more closely resemble those of ordinary deterministic calculus. This similarity to well-known mathematics may serve to make stochastic calculus accessible to a broader audience than in the past. The integral formulation is herein shown to be compatible with the Itô differential rule for non-Gaussian processes and is used to describe the increment of the nonstationary response of a system governed by a vector stochastic equation with parametric delta-correlated excitation.     

Assessment of ease of excavation of surface mines

An empirical ground classification system for surface mines is presented. It is designed to provide a means for determining the ease of excavation, diggability, by mechanical excavators. The background and the methodology for determining this excavation index is introduced. This index, which is suitable for rock characterization relies on the point load index of the rock, its block size as defined by the presence of discontinuities. The system is also flexible to account for the influence of weathering as well as the relative ground structure which may assist or hinder the excavation process. The economic consequences of selecting mining excavation equipment are also addressed. The Excavation Index was applied with success to 49 case studies (Hadjigergiou, J. Studies of machine ground interaction in surface mines. Ph.D. thesis, McGill University, 1993, p. 214).     

Assessment of effect of heat of internal friction on characteristics of structured flow of viscoplastic liquid in a round tube

A structured pressure flow of viscoplastic liquid in an infinite round tube is examined. Energy dissipation is given due consideration; it is assumed that the temperature dependences of the plastic viscosity and the ultimate shear stress are exponential. The solution obtained when the parameter characterizing the rate of production of heat of internal friction is assumed to be small indicates that energy dissipation has a sgnificant effect on the local flow characteristics and the hydraulic-resistance coefficient, for which an expression suitable for engineering calculations is given.     

大学物理《力学》中的自由度分析

对《力学》中的物体自由度进行多方面分析,以深化教学、提高学生正 确分析物理问题的能力.使用实际教学分析的研究方法,在《力学》范围内讨论自由度与坐标、 自由与约束的关系并得以下结论: (1) 同一物体的自由度随其所在的``空间'不同而不同, 不因坐标系的选取不同而 异, 在同类参考系中不因参考系的动静而有别;(2)自由度遵循叠加原理. 讨论了质点系的总自由度及相关计算问题,并指出研究《力学》中自由度的意义.