理论力学英文版Chapter 1
理论力学第7版第一章
物质层次 线度(m) 运动形式
学科
宇观
>108 天体运动 宇宙学,天体物理
宏观
10-3~103 机械运动 理论力学 ,经典力学
亚宏观 10-6~10-3 热运动 热学,统计物理
原子
10-10~10-9 电磁运动 电磁学,原子物理
核
10-14~10-13 核运动 核物理,高能物理
夸克
<10-8 基本粒子运动 粒子物理,色动物理
平衡时F3 必与 F12 共线则三力必汇交O 点,且共面.
公理4 作用和反作用定律 作用力和反作用力总是同时存在,同时消失,等值、
反向、共线,作用在相互作用的两个物体上.
在画物体受力图时要注意此公理的应用.
公理5 刚化原理
变形体在某一力系作用下处于平衡,如将此变形体刚 化为刚体,其平衡状态保持不变。
• 理论力学(广义):在公理基础上通过数学 推导建立运动与力的关系。
牛顿定律、Lagrange原理、Hamilton原理
• 理论力学(狭义):研究质点、质点系和刚 体系的平衡、移动、转动及振动等运动 规律。不研究连续介质。
矢量力学(几何力学):以伽利略、牛 顿定律为基础。
分析力学:以变分原理为基础。
机械原理、机械设计、结构力学、弹塑性力学、飞 行力学等。 o 学会一种研究方法。
送给大家的话
勤于观察 善于思考 富于联想 勇于创新
学会学习 学会关心 学会反省 学会感激
静力学引言
静力学 (Statics):
研究物体的受力分析、力系的等效替换(或简化)、建 立各种力系的平衡条件的科学.
1、物体的受力分析:分析物体(包括物体系)受 哪些力,每个力的作用位置和方向,并画出物体的 受力图.
理论力学第七版
公理3 (Axiom 3) 加减平衡力系原理(The Principle of Addition or 公理
Subtraction Equilibrium Forces System)
推理1 推理 (Inference 1) 力的可传性(The Principle of Transmissibility) 推理2 推理 (Inference 2) 三力平衡汇交定理(Theorem of Three-force
被约束体
轴可在孔内任意转动, 轴可在孔内任意转动, 也可沿孔的中心线移动, 也可沿孔的中心线移动,但 轴承阻碍轴沿孔径向向外的 约束 位移。 位移。
第一章 静力学公理和物体的受力分析
1-2 约束和约束力 -
1-2 Constraints and Reactions of Constraints 反力方向 过接触点,沿接触面公法线指向轴心。 过接触点,沿接触面公法线指向轴心。 由于轴在孔内可任意转动, 由于轴在孔内可任意转动,故而轴 与孔的接触点位置是不定的。 与孔的接触点位置是不定的。因此反力 的方向一般预先不能确定。 的方向一般预先不能确定。但这样的一 个反力常用两个过轴心的, 个反力常用两个过轴心的,大小未知的 正交分力F 来表示。 正交分力 AX、FAY来表示。此二力指向 可任意假定。 可任意假定。
1-2 约束和约束力 - 约束和约束力(Constraints and Reactions of Constraints)
约束特点 阻碍物体沿接触面法线,并指向约束的运动。 作用点 接触点 反力方向 过接触点,沿接触面公法线,指向被约束物体
第一章 静力学公理和物体的受力分析
1-2 约束和约束力 - 约束和约束力(Constraints and Reactions of Constraints)
理论力学中英文第一章
2021/7/31
5
2021/7/3N1anchang Hangkong University
力系 Force system 一群力可分为:平面汇交(共点)力系;平面平行力系;平面力 偶系;平面任意力系;空间汇交(共点)力系;空间平行力系; 空间力偶系;空间任意力系。
Force system is defined as a group of forces which act on the
same body.
Classification of force system Coplanar force system can be classified as coplanar concurrent force system, coplanar parallel force system, coplanar force-couple system and general coplanar force system. Forces in space can be classified as spatial concurrent force system, spatial parallel force system, spatial force-couple system, general spatial force system.
but opposite sense. F1F2
Maple理论力学I第2版教学课件ppt作者李银山第1章绪论
混沌理论是自相对论和量子力学问世以来, 对人类整个知识体系的又一次巨大冲击,作为非 周期的有序性,混沌无处不在;既存在于广袤无 垠的宇宙,又存在于结构精细的人脑。因此,混 沌动力学的发展必将引起人们自然观的彻底改变。 面对这一重大的科学变革,我们每一个力学工作 者应该认真考虑,如何将混沌动力学这一现代数 学的主题引入力学课程的教学,以使新一代的科 学工作者适应这一变革,是一件极为重要而有意 义的事情。本书作为尝试在提高部分引入了分岔、 混沌和非线性振动的内容。
给出了计算的构造性步骤,但如果没有当代快速计算机作为 工具,要实现这样的算法是根本不可能的。
符号计算又称为符号与代数计算,符号 代数,符号操作等等,它的正式名称是 “计算机代数”。而为实现计算机代数的 软件包,叫做“计算机代数系统”。在过 去四十年中,计算机代数无论在基础研究 或程序设计方面,发展都很迅速,迄今交 付使用的系统数以百计。这些系统,按其 用途可分为两大类。
•
讲授理论力学要始终以数学建模思想为核心。什么是
数学建模呢?如果一定要下一个定义的话,可以说它是一
种科学的思考方法,是对现实的现象通过心智活动构造出
能抓住其重要且有用的特征的表示,常常是形象化的或符
号的表示。从科学,工程,经济,管理等角度看数学建模
就是用力学的模型和数学的语言和方法,通过抽象、简化,
• Maple是产自加拿大的一个计算机数学软件。1980年9月,加拿大 Waterloo大学的符号计算研究小组成立,开始了用计算机实现符号计 算的项目研究,数学软件Maple就是这个项目的产品。Maple是一个 对大众公开的计算机代数系统,它具有以下特征:
试问它们在有理数域中是否可约,并将其分解为不可约因子的乘积。 这可不是一项单凭谨慎和耐心就能完成的任务
1Basic concepts and bearing
Lesson 1 Basic Concepts in Mechanics
Since no humans can lift 300 kilograms directly, a device must be employed to modify the required effort into something manageable. One common device is an inclined plane-in this case, a loading ramp that slopes from the ground to the truck, if the ramp were 10 metres long and friction forces were negligibly small, then 75 kilograms of force would be required to roll the machine up the ramp.
Lesson 1 Basic Concepts in Mechanics
In the loading ramp example, the ideal mechanical advantage is 4, since the input distance is 10 metres (the length of the ramp) and the useful load distance is two and onehalf metres (the vertical distance the load travels). An inclined plane is always a forcemultiplying machine. For speed-multiplying machines the input distance is less than the load distance and the ideal mechanical advantage is less than 1.
《理论力学(英文)》教学大纲
《理论力学(英文)》课程教学大纲一、课程基本信息英文名称 Theoretical Mechanics 课程代码 PHYS3108课程性质 专业必修课程 授课对象 物理学、物理学(师范) 学 分 3学分 学 时 54学时主讲教师 修订日期 2021年9月指定教材 G. R. Fowles & G. L. Cassiday. Analytical Mechanics (7ed),Brooks/Cole,2005.二、课程目标(一)总体目标:通过本课程的学习,使学生掌握质点、质点系和刚体的牛顿力学和分析力学的基本理论;在教学中通过对牛顿力学、分析力学、刚体转动和振动系统等问题的深入讨论,强化学生对理论力学基本概念和基本原理的理解;使学生体会物理学思想及科学方法,更好地理解科学本质,培养分析和解决现实生活中力学问题的能力,也为后续学习量子力学、固体物理等专业课程打下扎实基础。
(二)课程目标:课程目标1:了解理论力学的发展史及其与当代物理学其他学科的关系。
对相关的重要物理学家,如哥白尼、伽利略、第谷、开普勒、牛顿、欧拉、拉格朗日、哈密顿等人所作的贡献予以介绍。
帮助学生体会物理学家的物理思想和科学精神,建立科学的世界观和方法论。
课程目标2:熟练运用高等数学和矢量分析等数学工具,掌握牛顿力学和分析力学的基本原理,加深对宏观机械运动规律的系统认识,提高抽象思维与逻辑推理能力,培养学生对生产、生活中力学问题的求解能力。
课程目标3:讲解数值计算方法在解决具体力学问题中的应用,提高学生编程和分析数据的能力,培养学生科学探究的兴趣。
同时通过全过程的英文教学,提高学生运用英文阅读专业资料、交流和写作的能力,为今后独立钻研创造条件。
(三)课程目标与毕业要求、课程内容的对应关系表1:课程目标与课程内容、毕业要求的对应关系表课程目标对应课程内容对应毕业要求三、教学内容第一章 数学知识准备1.教学目标课程目标1第一章 数学知识准备 第二章 质点牛顿力学 第三章 分析力学 第四章 有心力问题第五章 非惯性参照系力学 第六章 质点系力学 第七章 刚体力学 第八章 振动系统动力学 毕业要求3:了解物理学前沿和发展动态,新技术中的物理思想,熟悉物理学新发现、新理论、新技术对社会的影响。
理论力学之速度(英文)
va ve vr
va ve vr
va—absolute velocity of the moving point; vr—relative velocity of the moving point; ve—convected velocity of the moving point, which is the velocity of a point (convected point) on the MCS;
2) Relative motion: motion of the moving point relative to the MCS.
3) Convected motion: motion of the MCS relative to the SCS.
4. Three kinds of velocity and acceleration convected point: the point in the MCS coinciding with the moving point at any instant of time. Image that the moving point were fixed to the MCS and moved together with the MCS. Such a point in the MCS is called convected point. The velocity and acceleration of the moving point in its absolute motion are called absolute velocity v a and absolute acceleration The velocity and acceleration of the convected point in its absolute motion are called convected velocity v e and convected acceleration v r
理论力学(周衍柏)第一章质点力学
0 :人行走速度, :风速(相对于地), :风相对于人
的速度
由:
得:
理论力学:Theoretical mechanics
得:
解得:
2 y 2
x 4,y 4 因此:
风向:西北风 以矢量方式求解:
理论力学:Theoretical mechanics
理论力学:Theoretical mechanics 方向: 可用速度与三个坐标轴的方向余弦表示
/ cos(v , i ) v x / v x / cos(v , j ) v y / v y / cos(v , k ) v z / v z 2 y 2 z 2 x 2 y 2 z 2 x 2 y 2 z 2 x
这是常用的运动学方程,尤其当质点的轨迹未知时。它是 代数方程,虽然依赖于坐标系,但是运算容易。 (3)极坐标下的运动学方程
r r时,其位臵也可用极坐 标确定。
理论力学:Theoretical mechanics (4)自然坐标形式的运动学方程 s s(t ) 对运动轨迹已知的质点,常用此方程。用自然法研究运 动,运算比较简便,各运动参数的物理意义明确。 质点在参考空间中的位臵还可用其它的方法确定,例如 柱坐标法或球坐标法。通过坐标形式的方程表示质点的运 动方程,并由此继续描述质点的其它运动量的方法称为分 析方法。 2、轨道 质点运动过程中在空间描述出的连续曲线, 运动学方程中 消去t得轨道方程。(直线运动、曲线运动)。 三、位移、速度、加速度 1、位移:
理论力学:Theoretical mechanics
r
2、速度:
理论力学:Theoretical mechanics
chapt01_Introduction理论力学 第一章 英文
1 - 12
Correcting the Error
• Can you tell what is wrong? • 17th century Hooke’s law • 1729 Bernard Forest de Balidor following the earlier lead of Leibniz and P. Varignon found that
1-8
Failed Liberty ship, c.1940
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
1-9
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
1 - 17
1.2 Continued
• Force is a vector; point of application, magnitude and direction • Study the conditions of rest or motion of particles and rigid bodies in terms of the four basic concepts • Particles; a very small amount of matter which may be assumed to occupy a single point in space • Rigid bodies; a combination of a large number of particles occupying fixed positions with respect to each other
理论力学双语1
The great English scientist Newton(1643~1727) published the book Mathematical Principles of Natural Philosophy in 1687. It sums up all his studies and brings forward the three fundamental laws of mechanics, the law of universal gravitation and the laws at celestial mechanics. He is the founder of mechanics. Bernoulli (Swiss, 1667~1748) found the principle of virtual displacements. Euler (Swiss, 1707~1783) published the book Mechanics which used differential equations to study mechanics. D’Alembert (French, 1717~1785) evolved d’Alembert’s principle.
Theoretical Mechanics
Introduction
1. The object of theoretical mechanics 2. The task and content of theoretical mechanics 3. The basic logical concepts in theoretical mechanics 4. A brief history of theoretical mechanics 5. Methods of modern teaching of theoretical
理论力学第一章英文精品PPT课件
(1)The representation of force in space:
g b
O
q
Fxy
a force is given by its magnitude, its direction and its point (line) of application magnitude: F F
point of application: the point at which the force acts onto the object.
Chapter 1: Fundamental principles of statics and force analysis
§1.1 Fundamental concepts in statics §1.2 Principles of statics §1.3 Constraints and their reaction forces §1.4 Force analysis and force diagrams
direction: it can be determined by the three angles , b, g or by the angle of inclination q and the angle of depression .
(2) The method of direct projection
Force system
coplanar force system Force system in space
Coplanar force system: 1 coplanar system of concurrent forces 2 coplanar system of parallel forces 3 general case of a force system in a plane
理论力学(双语)
2.5 Cartesian Vectors
How will you represent each of the cable forces in Cartesian vector form?
Given the forces in the cables, how will you determine the resultant force acting at D, the top of the tower?
2.1-2.2 Vectors and Scalars
1. Which one of the following is a scalar quantity? A) Force B) Position C) Mass D) Velocity 2. For vector addition you have to use ______ law. A) Newton’s Second B) the arithmetic C) Pascal’s D) the parallelogram A vector is a quantity that has both a magnitude and a direction. Vector operations include multiplication and division by a scalar; addition; subtraction and resolution.
ENGINEERING MECHANICS STATICS
Zheng Tinghui Ph. D DEPT. OF Applied Mechanics SICHUAN UNIVERSITY
Mechanics
Study of what happens to a “thing” (the technical name is “BODY”) when FORCES are applied to it. The subject is subdivided into three branches:
理论力学-英文版
理论力学-英文版Theoretical Mechanics(理论力学)Course Code:83031000Course Name: Theoretical MechanicsCourse Credit: 3Course Duration: the fifth termTeaching Object: undergraduate students of the Applied Physics MajorPre-course:Mechanics, Advanced MathematicsCourse Director: Wu Zhongchen, Lecturer, Doctor of Science Course Introduction:The course mainly expounds classical mechanics theory. This course consists of two volumes. volume ? covers the content of statics(Including the free-body diagram,planar force systems and couple systems, etc.), kinematics(Including the kinematics of a particle, the simple motion of a rigid body,resultant motion of a particle,etc.), dynamics(Including the particle dynamics,theorems of linear momentum,angular momentum and kinetic energy of particle systems ). V olume ?? covers analytical mechanics (Including the fundamental equations of dynamics, Lagrange's equations of the first and the second kind, etc.)and mechanics vibration(Including the free and forced vibration of the systems with one and two degrees of freedom, isolation of vibration,dynamic vibration inhibitor,etc.).Course Examination:Final achievement=usual performance*30%+ Final Examination*70%The usual performance includes whether the students are punctual for class, attendance rate, answering questions, Exercises out of Class.The Final adoptes the close examination.Appointed Teaching Materials:The theoretical mechanics teaching and research section of HARBIN institute of technology(哈尔滨工业大学理论力学教研室). “Theoretical Mechanics(理论力学)”. Higher Education Press (高等教育出版社), the second edition on August, 2002 (2002年8月第二版).Bibliography:[1]Zhou Yanbai ( 周衍柏).“Theoretical Mechanics(理论力学教程)”. Higher Education Pre ss (高等教育出版社), the second edition on March, 1986(1986年3月第二版).[2] Wang Zhenfa (王振发),. “ Analytical Mechanics (分析力学)”. Science Press (科学出版社), the first edition on March, 2003 (2002年3月第一版).。
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• Law of Inertia(惯性定律):A body in motion and free from external forces will keep moving at a constant speed and in a straight line. • A particle (质点):is a body whose size e forces acting on it. P3 • A rigid body(刚体) means a body does not deform under the action of forces. It is an ideal mechanical model. P4
Chapter 1 Review of Concepts in Mechanics Equilibrium(平衡)defines as a body at rest or P2 moving with constant velocity. Resultant(合力)is the sum of forces. Parallellogram Law (平行四边形法则) Vector(失量)Scalar (标量)Projection(投影) Principal of Virtual Work (虚功原理) P3 •Load(荷载) :the forces acting on a body. It includes concentrated load and distributed load.
Mechanical Model
Newton’s Laws of Motion
First Law: In the absence of applied forces, a particle originally at rest or moving with a constant speed in a straight line will remain at rest or continue to move with constant speed in a straight line. Second Law: If a particle is subjected to a force, the particle will be accelerated . The acceleration of the particle will be proportional to the magnitude of the net force and inversely proportional to the mass of the particle. Third Law: For every action, there is an equal and opposite reaction. Or, the mutual forces exerted by particles on each other are always equal and oppositely directed.