工科理论力学教学改革刍义

本文分析了工科理论力学教学改革的几种传统作法,阐述了当教学中存在的主要问题及相应的改革措施。     

基于网络的工科《理论力学》多媒体教学系统

通过对教学系统，教学媒体以及现代教育技术的分析和讨论，探索了“基于网络的多媒体教学系统”，这一现代教育技术的必要性，可行性以及实现该系统的构思。     

新工科背景下力学跨学科课程的建设与探讨

新一轮科技变革业已开始,我国正在大力推动“新工科”建设。力学专业作为工科的关键基础之一,需要结合新时代工程教育改革方向来推进专业教育与学科建设。本文以生物力学与仿生跨学科课程为例,分析了当前跨学科课程所面临的学生缺少了解、教师定位不清、教学方式单一等问题,提出了与低年级通识教育、基础力学课程、现代教育技术相结合的针对性措施,并对其实施效果进行总结,以期为现有工科中的跨学科课程建设提供借鉴和参考。     

工科理论力学教学体系的改革

本是作1987年以来工科理论力学教学体系改革的简要总结。静力学完全采用以动力学为基础的理论体系,分“力系作用量、等效、简化”、“受力分析”、“平衡力系作用下物体的受力”三章,各部分系统清晰,内容完整,避免重复。运动学强调解析法;刚体平面运动置于点的复合运动之前;用点在不同参考系中的运动讲点的复合运动,三个定理合为一个定理,讲透动点动系的选择。动力学强调动力学基本定理,相对运动动量矩定理根本上取代动静法,加强动能法求加速度。加强综合习题课。     

新媒体创作在工科基础课程教学中的应用——以理论力学课程为例

随着我国高等教育迈向深化改革的新发展阶段,传统工科教学也面临理论结合实践、基础结合创新、传统结合多元的改革新目标和新要求。本研究以理论力学课程教学为例,提出了一种以学生为主体的短视频创作在工科基础课程教学中的应用模式,有效提升了学生学习效率和知识掌握程度,对开拓学生学习能力和创新思维具有显著促进作用。该模式为工科多元教学提供了新的思路,对与时俱进优化工科教学改革具有重要参考价值。

     

基础力学课程教学与课程思政的协同建设与实践1)

本文阐述了基础力学课程教学与课程思政建设相互支撑和相互促进的基本特征与相应举措,特别提出了基础力学课程思政建设的难点与重点。通过两个课程思政建设案例分析了课程教学与课程思政协同建设与不断深化的实践过程和效果。     

整合·开放·超越——对改革我国工科力学教材的思考

本文通过对我国工科力学课程设置、教材内容和体系等方面存在问题的简略分析,初步论述了力学教材改革的三条基本思路,即：合理整合,建立新的力学系列课程体系;走向开放,突破封闭性的知识结构;更新内容,正确处理继承与超越的关系     

整合·开放·超越——对改革我国工科力学教材的思考

本文通过对我国工科力学课程设置、教材内容和体系等方面存在问题的简略分析，初步论述了力学教材改革的三条基本思路，即：合理整合，建立新的力学系列课程体系；走向开放，突破封闭性的知识结构；更新内容，正确处理继承与超越的关系     

工科理论力学教学改革刍议

本文分析了工科理论力学教学改革的几种传统作法,阐述了当前教学中存在的主要问题及相应的改革措施．     

A Numerical Solution of the Inverse Problem in Classical Celestial Mechanics,with Application to Mercury's Motion

It is attempted to obtain the masses of the celestial bodies, the initial conditions of their motion, and the constant of gravitation, by a global parameter optimization. First, a numerical solution of the N-bodies problem for mass points is described and its high accuracy verified. The osculating elements are also accurately computed. This solution is implemented in the Gauss iterative algorithm for solving nonlinear least-squares problems. This algorithm is summarized, and its efficiency for the inverse problem in celestial mechanics is checked on a 3-bodies problem. Then it is used to assess the accuracy to which a Newtonian calculation may reproduce the DE403 ephemeris that involves general-relativistic corrections. The parameter optimization allows one to reduce the norm and angular differences between the Newtonian calculation and DE403 by a factor 10 (Mercury, Pluto) to 100 (Venus). The maximum angular difference of the heliocentric positions of Mercury is ca. 220 per century before the optimization, and ca. 20 after it. The latter is still far above the observational accuracy. On the other hand, Mercury's longitude of the perihelion is not affected by the optimization: it keeps the linear advance of 43 per century.     

Models in the Engineering Mechanics of Polymer-Matrix Composite Systems

This paper discusses the complete system of structural, thermochemical, and mechanical-mathematical models that describe all the phenomena accompanying the formation of polymer-matrix composite materials (PCMs) and structures made of them. The issues of optimizing design engineering and modeling the postprocess behavior of PCM structures are addressed     

基于概率的工程结构动力特性优化设计

首先对结构材料物理参数为随机变量时 ,结构刚度和质量矩阵的建立以及结构特征值随机变量的数字特征进行了推导。在此基础上 ,构造了具有频率或频率禁区可靠性约束的工程结构动力优化数学模型 ,并对其中关切频率的估定 ,两种频率约束的统一表示等进行了讨论。优化求解采用子空间迭代和复合形方法。最后通过桁架和梁结构两个算例 ,说明文中模型和方法的正确与可行。     

Solution of the Three-Dimensional Thermoelastic Problem in Stresses

A method is proposed for constructing a general solution to the three-dimensional thermoelastic equations in stresses (compatibility conditions and equilibrium equations). This general solution is valid for both an elastic half-space and an elastic layer. The second thermoelastic boundary-value problem for a half-space is studied in detail as an example     

《计算力学学报》引文及基金论文定量分析

运用文献计量学方法,通过对全国中文核心期刊《计算力学学报》10年来(1997～2006年6月)所发论文引文(包括引文的数量、语种、类型和年代分布)及基金论文(包括基金论文的数量、获的数量、资助机构和基金论文作者的地域分布)的定量分析,客观揭示该刊在我国学术界的整体水平及重要影响.     

The Stress State of Three-Dimensional Bodies with Nonsmooth Inclusions

The stress state of a three-dimensional body with inclusions bounded by surfaces with singular lines (sets of corner points) and a conical point is studied. By determining the asymptotics of displacements and stresses at the singularities of interfaces and using the generalized elastic potentials of single and double layers, the problem posed is reduced to a system of singular integral equations. The results obtained are used to analyze the stress state of a body with a circular conical inclusion     

输电线路挤扩支盘桩受力特性的试验研究

挤扩支盘桩是一种具有较高的承载力和较小的沉降变形的新桩型。对某220kV送电线路工程的挤扩支盘灌注桩分别开展了下压+水平联合工况、上拔+水平联合工况和水平荷载的现场真型静载荷试验,得到了挤扩支盘桩在不同工况下的承载力、桩身轴力、桩周侧阻力和桩端阻力的分布规律。支盘桩的抗拔承载力较普通灌注桩提高约20%,支盘的存在使得桩身轴力呈现明显的阶跃式变化。根据挤扩支盘桩的荷载传递规律,建议承力盘间距不小于桩身设计直径的4倍,且不小于承力盘设计直径的2倍。     

Motion of a Mechanical System with Variable Mass–Inertia Characteristics

A closed-form system of dynamic equations describing the free motion of a material system with variable mass–inertia characteristics is derived. The system consists of a carrying body and carried bodies (freight) and undergoes translational–rotational motion in space. The differential equations of motion derived include time-dependent parameters and allow for the inertia and varying mass of the system, etc. It is pointed out that special cases can be derived from the general equations to study various modes of motion and stability phenomena     

Three-Dimensional Interaction of a Blunt Cone with a Hot Region in a Supersonic Flow in the Presence of Surface Injection

The problem of the interaction of a blunt cone placed at zero incidence in a supersonic flow with a spherical hot region in the incident flow is considered for the case in which the hot region center is displaced relative to the axis of symmetry of the body. Two cases are studied: (1) the interaction of temperature inhomogeneity with an impermeable conical surface and (2) interaction in the presence of intense surface injection localized on the spherical bluntness of the body. It is shown that strong surface injection considerably improves the flow pattern and the aerodynamic characteristics of the body.     

Calculation of the Flow Pattern and the Heat Fluxes in the Interaction of a Shock Wave with a Cylinder in a Supersonic Flow

The problem of determining the mechanical and thermal action on a cylinder in a supersonic flow with account for the interference between an incident shock and the detached bow shock has been studied extensively, both experimentally and theoretically, in the last few decades [1–12]. A fairly complete survey can be found in monograph [12]. The interest in the problem is mainly due to the fact that in this case the so-called fourth type of shock interaction can occur, leading to a sharp local increase in the mechanical and thermal loads. As for the problem of the interference flow past a cylinder itself, it can serve as a model problem for testing techniques of calculating the separation flow past the controls of hypersonic flight vehicles.In this paper, we attempt to demonstrate the possibility of using a fairly simple approach to the calculation of the above-mentioned flows, including those with a separation zone. The approach is based on a combination of numerical simulation within the framework of the inviscid gas model and subsequent calculation of the heat transfer parameters and does not require an excessive amount of computing power.