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chapt01_Introduction理论力学 第一章 英文

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理论力学第7版第一章

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．

理论力学中英文第一章

理论力学中英文第一章
在已知力系上加上或减去任意的平衡力系，并不改变原力系 对刚体的作用。 The rigid body will remain unchanged if a equilibrium force system is added or subtracted from the original force system acting on the rigid body.
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

流体力学英文版第一章绪论—Introuduction

流体力学英文版第一章绪论—Introuduction
7 / 38
Expression of fields
Noห้องสมุดไป่ตู้es
Vector fields: Velocity field, V = (V(r, t)) = (u(r, t), v(r, t)). For a streamline, it satisfies dr × V = 0.
The mechanics is built on the base of the corresponding engineering problem, physical models, and mathematic models or algorithms.
Deformation is also important in mechan-
Content
1. Curse overview 2. Field 3. Indicial notation 4. Fluid properties
Notes
1 / 38
Curse overview
Notes
Fundamentals of Fluid mechanics
Chapter I Physical properties of fluid mechanics Field, Indicial notation, fluid properties. Chapter II Fluid statics Fluid is either at rest or moving without shearing stresses. Chapter III Fluid kinematics The description and visualization of its motion. Chapter IV Fluid dynamics The analysis of the specific forces necessary to produce the motion: Idea flow and viscous flow. Chapter V Dimensional analysis (Option) Buckingham Π theorem to conduct dimensional analysis.

《理论力学(英文)》教学大纲

《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。

(完整版)理论力学第一章课件

(完整版)理论力学第一章课件
相应地，作用在物体上的力矢量是定位矢量。
注意点： 1、力的可传性只适用于刚体。 2、沿作用线滑移。 3、传到刚体内另一点。
公 理 3
推理2 三力平衡汇交定理
作用于刚体上三个相互平衡的力，若其中两个
成绩评定： 平时成绩：20分
期末成绩：80分
基础课： 数学、物理
理论力学
后续力学课： 材料力学、 结构力学、 弹性力学等
专业基础课： 机械原理、 机械零件等
专业课
技术基础课
理论力学是工程类专 业第一门技术基础课
实例一 塔式起重机
平衡块
实例二 车床车螺纹
车螺纹
将直径为d的圆柱毛胚（或叫工作物）安装 在车床轴上，要车出螺距为h的螺纹，如何合理 调整轴的转速n与车刀速度u？
第 公理1 力的平行四边形法则
一
章
F2
FR 矢量表达式：
表A示为： F1
亦可用力三角形求得合力矢
F2
FR
公 表A示为： F1
a
理
1
力的三角形法则
FR F2 F2
F1
FR
b
F1
1、分力矢首尾相接 2、合力矢箭头与第2个矢量的箭头相碰
注意点：
1、分力的顺序改变，力三角形的形状也改
变，但合力的大小、方向不变。
公 理 2
公理3 加减平衡力系原理
在已知力系上加上或减去任意的平衡力系，

并不改变力系对刚体的作用。
公
理
3
加减平衡力系原理只适用于刚体
推理1 力的可传性
作用于刚体上某点的力，可以沿着它的作用线移 到刚体内任意一点，并不改变力对刚体的作用。
公 理
F
= = B

理论力学教程(第一章)

理论力学教程(第一章)

约束结构：两个物体2、3上钻同样大小 的圆孔，并用圆柱销钉1 穿入圆孔，将 两个物体连接起来。（轴向与径向）
约束特性：物体只能绕销钉轴线相对转动， 但不能在与销钉轴线相垂直的方向上有任 何相对位移。
约束力：在垂直于销钉轴线的平面内并 通过圆心，但方位和指向不能确定。通 常将其表示为大小未知的两个正交分力，
若刚体受三个力作用而处于平衡，且其中二力作用线 相交于一点，则这三个力必位于同一平面内，且它们的 作用线必定汇交于一点。
公理4 作用与反作用定律
两物体间的相互作用力，大小相等，方向相反，作 用线沿同一直线。
F = -F'
·此公理概括了物体间相互作用的关系，表明作用力与 反作用力成对出现，并分别作用在不同的物体上。
材料力学
高等数学 大学物理
理论力学
结构力学 水力学
机械原理
其他专业课程
学习理论力学的目的
理论力学是现代工程技术的重要基础理论之一 理论力学研究力学的最基本规律，是学习一系列后续课
程的重要基础 有助于我们树立辩证唯物主义的世界观，提高分析问题
和解决问题的能力
理论力学的学习方法
学习理论力学必须反复地理解它的基本概念和公理或定律,以及由 这些定理和结论引出的基本方法。 掌握抽象化的方法，理论联系实际，要逐步培养把具体实际问题 抽象成为力学模型的能力 独立做大量的习题和思考题。
例1-1
碾子重为 P，拉力为F ，A, B处光 滑接触，画出碾子的受力图。
解：画出简图
画出主动力 画出约束力
C
例1-2 受AB杆力分析
D
A
B
FAx FAx A
FB
D
B
A
FA
p

工程力学英文版课件00 Introduction


Stability:
Capacity of a component or a structural element to retain the original state of equilibrium.
18
Under the requirement that the strength, rigidity, stability criteria are satisfied, provide the necessary fundamental theory and method of calculation for determining reasonable shape and dimension, choosing proper materials for the components with the most economic price.
21
Concentrated Force: A concentrated force represents the effect of a loading which is assumed to act at a point on a body. Force is defined as any action that tends to change the state of rest of a body to which it is applied. Three properties of force: Magnitude Direction Point of application
Transmissibility of Force The point of application of a force may be moved along its line of action without altering the effect of the force on any rigid body to which it is applied.

理论力学英文版Chapter 1


• 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.

大学物理讲义 英文1-Introduction


Examples: 1. x=x1+x2 2. x=t+m 3. v= x/t 4. E=1/2mv2
[x]=L, [x1]+[x2]=L, left side=right side [x]=L, [t]+[m]=T+M, left side ≠ right side [v]=L/T, [x]/[t]=L/T, left side=right side [E]=ML2/T2, 1/2[m][v2]= ML2/T2, left side =right side

Length

Units

SI – meter, m


One meter is defined the distance traveled by light in a vacuum during a time interval of 1/299792458 second With this definition, we establishes the speed of light to 299792458 m/s


We will use the rules for significant figures to approximate the uncertainty in results of calculations
Significant Figures



A significant figure is one that is reliably known All non-zero digits are significant Zeros used to position the decimal point are not significant.

力学专业英语-Lecture_1_Introduction


• How are you doing? • How is life?
EVERY DAY GREETINGS
“Good morning”
“Good evening” “Good afternoon” “Good Night” “Goodbye”
What can you say to someone when you meet them for the first time?
Topics
Is greeting and introduction important?
What is a good greeting or introduction? How to make foreign friends?
Write your own opinion and submit it to qingheБайду номын сангаасao@.
Activities 2：
Using the above format, introduce the your partner at
a formal function.
FORMAL GREETINGS
Greeting
• Good Morning, Mr. Jack • Good Afternoon, Mr. Blue • Good Evening, Mommy
Listening
Most people are born with good hearing, but not good
listening skills. Listening must be learned. Listening is a mental process requiring effort, and we can learn how to be good listeners.
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1 - 19
2. The Principle of Transmissibility
– The conditions of equilibrium or of motion of a rigid body will remain unchanged if a force acting at a given point of the rigid body is replaced by a force of the same magnitude and same direction, but acting at a different point
h WL S bh 3 2 Sbh W 3L
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
1 - 13
Forest’s Postulation
S
h WL S bh 3 2 Sbh W 3L
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
1 - 18
Six Fundamental Principles
• All principles are based on experimental evidence, not from mathematical derivations 1. Parallelogram law for addition of Forces
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.
W
1 - 14
Edme Mariotte’s experiments; while designing pipelines to supply water to the palace at Versailles
1 - 10
Galileo’s Postulation
S
h WL S bh 2 2 Sbh W 2L
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
W
1 - 11
Galileo, 1638
b XL S bh 2 Sbh2 Shb2 W , X 2L 2L W b X h
© 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
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
1-2
1.2 Fundamental Concepts and Principles
• Study of Mechanics goes back to Aristotle (384322 B.C.) and Archimedes (287-212 B.C.) • Isaac Newton (1642-1727) • D’Alembert, Lagrange and Hamilton • Einstein; theory of relativity (1905)
1 - 16
1.2 Continued
• Basic concepts used in mechanics; space, time, mass and force • Space; position of the point P; coordinates of P with reference to the origin • In Newtonian mechanics; space, time, and mass are absolute concepts, independent each other (force is not independent) • Note; relativistic mechanics time is not independent
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
1-5
Galileo’s seminal work on strength of materials and dynamics Dialogues Concerning Two New Sciences
– – – – Was not pubished by French Academy Many misprints and poorly edited He was not a clear writer He criticized many other’s work
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
Galileo’s illustration of two failure modes
© 2004 The McGraw-Hill Compaeserved.
1-7
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
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
1.1. What is Mechanics?
• The science which describes and predicts the conditions of rest or motion of bodies under the action of forces 1. Mechanics of rigid bodies (GE 204, 205) 2. Mechanics of deformable bodies (GE 206) 3. Mechanics of fluids (CE, ME 308)
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
1-4
• Renaissance shipbuilders found that their large timber ships were breaking under their own weight • Galileo (1638) prefaced his seminal study of strength of material by reciting the breakup of ships, etc. • Still there are failures of heavy steel ships and large missiles • Factor of safety or factor of ignorance?
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
1-3
Aristotle
• Fourth century B.C.E. • Mechanical Problems; collections of questions and answers; in physics, mathematics and engineering • Among 35 mechanical problems posed by Aristotle
© 2004 The McGraw-Hill Companies, Inc. All rights reserved.
1 - 15
• Marriotte recognized that there must be linearly varying compression as well as tension acting across the beam’s section • He had error in calculating resultant moment, and he used Galileo’s formula • 1713, A. Parent found correct treatment but was ignored because