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工程力学英文版课件01 Concurrent Forces

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工程力学全英文Engineering Mechanics (2)

工程力学全英文Engineering Mechanics (2)
Fundamental Concepts and Principles of Statics
Fundamental Concepts and Principles of Statics
Fundamental Concepts of Statics
Force is the mechanical interaction between bodies that changes or tends to change the motion state or the shape of the body on which it acts.
opposite senses. Fifth Principle (Principle of Solidification)
C
The system will
move.
F If a freely deformable body (or body system)
subjected to the action of a force system is in M
without
changing
its
external
effect
on
a
rigid
body.
(Forces
are
sliding
vectors)
F
F F' F F
F
A
B
A
=
B
=
A
B
Fundamental Concepts and Principles of Statics
Third Principle (Principle of Force Parallelogram)
Fundamental Concepts and Principles of Statics

工程力学英文版课件03 Nonconcurrent Forces

工程力学英文版课件03 Nonconcurrent Forces

R' F' A F B C D O P'
M F AB OC F R, OA AB CD CD OC AB OA OC CD AB OA
18
R
P
OC M R CD R AB F AB M OA
A given couple may be moved about in its plane of action without changing its effect on a rigid body.
+
-
5
2. Transmissibility The force F acting on a rigid body has the properties of a sliding vector and can therefore act at any point along its line of action and still create the same moment about point O. This is the principle of transmissibility. It is important to realize that only the external effects, such as the body’s motion or the forces needed to support the body if it is stationary, remain unchanged after F is moved.
d F F F
13
d
F
The moment produced by a couple is called a couple moment. Its value can be determined by finding the sum of the moment of both couple forces about any arbitrary point.

工程力学英文版课件00 Introduction

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.

力学专业英语资料(一)考研必备

力学专业英语资料(一)考研必备

I. Theoretical Mechanics理论力学Gravitational Force, Gravity重力Concurrent Force汇交力, Coplanar Force共面力Force, Torque / Moment扭矩, Couple 约束力，反应，被动力，内力Constraint Force, Reaction, Passive Force, Internal/External Force 静力学直角坐标分量，合力，平行四边形准则Rectangular Components, Resultant Force, Parallelogram Law 1. Statics Composition of Force力的合成, Free Body Diagram隔离体Vector (Magnitude, Direction)矢量, Scalar标量静力平衡平衡方程平衡条件Net Force = 0Static Equilibrium, Equation of Equilibrium, Conditions for EquilibriumNet Torque/Moment = 0Rectilinear MovementMotion of Particle粒子运动Curvilinear Movement运动学 Translation平移2. Kinematics Motion of Rigid Body刚体运动Rotation扭转Linear线性的Velocity速度, Acceleration加速度Angular有角的Momentum, Kinetic Energy, Potential Energy动量，动能，势能动力学Moment of Inertia (Rectangular, Polar), Radius of Gyration惯性矩，回转半径3. Dynamics, Kinetics Centroid (Center of Mass/Gravity)中心Vibration, Oscillation (Free/Forced/Damped/Undamped)振动Simple Harmonic Motion, Period, Frequency简谐振动，周期，频率Pendulum, Centrifugal/Centripetal Force钟摆，离/向心力II. Mechanics of Materials材料力学材料强度 Compressive, Compression压缩1. Strength of Materials Tensile, Tension (Elongation, Extension)伸长Shear, Shearing剪切Linear, Hooke’s LawElastic弹性, Elasticity Non-linearViscoelasticity, Pseudo-elasticity, Super-elasticity粘弹性，拟弹性，超弹性应力应变关系塑性 Perfect Plasticity理想塑性2. Stress-Strain Relation/Behavior Plastic, Plasticity Viscoplasticity, Viscosity黏性, Creeping徐变, RelaxationBrittle脆性, Ductile柔性Work Hardening/Softening, Strain Hardening/Softening弹性模量，弹性系数 Young’s Modulus = Axial Stress / Axial Strain杨氏模量3. Modulus of Elasticity, Elastic Modulus Shear Modulus = Shear Stress / Shear Strain剪切模量Bulk Modulus = Volumetric Stress / Volumetric Strain体积弹性模量破坏理论，失效准则，屈服准则 Maximum Principal Stress Theory最大应力准则4. Failure Theory, Failure Criteria, Yield Criteria Shear Stress TheoryMohr-Coulomb Theory库伦理论Shear Force剪力, Bending Moment弯矩, Flexural Load弯曲荷载梁 Bending Stress弯曲应力, Normal Stress正应力, Shear Stress剪应力 (Horizontal/Longitudinal, Vertical/Transverse)5. Beam Neutral Axis中性轴, Flexure屈曲, Deflection挠曲Cantilever Beam悬臂梁, Simply Supported Beam简支梁, Pin-end, Fixed End固定端Uniformly/Linearly Distributed Load均布荷载, Concentrated Load集中荷载Buckling屈曲系数, Euler’s Equation欧拉方程6. Column 长细比，有效长度，临界荷载，偏心率Slenderness Ratio, Effective Length, Critical Load/Stress, Eccentricity RatioTension弹力, Compression压缩, Uniaxial/Axial Load单轴荷载7. Shaft杆, Rod长杆, Bar Inner/Outer Diameter内/外径Torsion扭转, Torque扭矩, TwistingRadial Distance辐射距离平面应变平面应力双向应力（单轴，三轴）应变能最大/小主应力8. Plane Strain, Plane Stress, Biaxial Stress (Uniaxial, Triaxial), Strain Energy, Major (Minor) Principal Stress Deformation变形, Displacement位移, Deflection偏向Stiffness, Rigidity刚度, Hardness硬度, Flexibility弹性, ComplianceDynamic Loading动力荷载, Cyclic/Fluctuating Loading脉冲荷载, Fatigue疲劳度Thermal Stress热应力/Strain/Deformation, Coefficient of Thermal Expansion热膨胀系数Factor of Safety安全系数, Safety FactorLimit State Design极限状态设计 (Ultimate Limit State极限状态, Serviceability Limit State正常使用极限状态), Probabilistic Design概率设计III. Structural Mechanics, Structural AnalysisRod, Shaft, Bar构件Beam, Girder1. Structural Element Column, PillarPlate, Shell, MembraneShear Wall, Shear Panel2. Truss构架, 3-hinge Arch, Rigid Frame刚性框架 (Joint节点, Pin-Joint, Hinge, Node)3. Statically Determinate静定, Statically Indeterminate超静定, Degree of Static Indeterminacy, N-fold Statically Indeterminate, Degree of Freedom自由度虚功原理 Virtual Displacement, (Matrix) Displacement Method, Stiffness Method4. Virtual Work Principle Virtual Force, (Matrix) Force Method, Flexibility MethodFinite Element MethodIV. Theory of Elasticity(Differential) Equilibrium Equation, Physical Equation, Compatibility/Geometrical EquationBoundary Conditions。

工程力学ppt课件

工程力学ppt课件

工程力学在土木工程中的应用
要点一
结构设计
土木工程中的结构设计需要应用工程 力学原理和方法，对建筑结构进行受 力分析、变形计算和稳定性评估。这 有助于确保土木工程结构的安全性和 稳定性。
要点二
土力学与地基工程
工程力学中的土力学理论和方法为地 基工程提供了支持。通过应用土力学 原理，土木工程师可以更好地理解和 评估地基的承载能力和稳定性，从而 优化地基设计。
工程力学的应用领域
建筑工程
建筑工程中的结构分析、抗震设计和施工过 程中的力学问题等。
航空工程
航空器的空气动力学分析、结构分析和优化 设计等。
机械工程
机械零件的强度、刚度和稳定性分析，以及 机械系统的动力学问题等。
水利工程
水坝、水闸和船闸等水利设施的设计、施工 和运行中的力学问题等。
工程力学的研究对象和方法
工程力学ppt课件
目录
• 工程力学简介 • 静力学基础 • 材料力学 • 动力学基础 • 工程力学在工程实践中的应用 • 工程力学的未来发展趋势和挑战
01
工程力学简介
什么是工程力学
工程力学是研究工程中物质和运动规 律的一门科学，涉及到物体的受力、 变形和运动等方面的知识。
工程力学结合了物理学和数学等多个 学科的知识，为各种工程实践提供基 础理论和解决方法。
载荷分析与校核
载荷分析是机械设计中的重要环节，通过工程力学的方法，设计师可以精确地预测和评估 机器在各种工况下的载荷情况，从而进行零部件的强度校核和优化设计。
摩擦与磨损研究
工程力学也涉及到摩擦与磨损的研究。这为机械设计师提供了关于摩擦、磨损和润滑的机 理和方法，有助于减少机器的摩擦和磨损，提高机器的效率和寿命。

工程力学全英文Engineering Mechanics (5)

工程力学全英文Engineering Mechanics (5)

A
A
A
FNA A
Support Reactions and Free-Body Diagrams
4. Pin support Two or more bodies are constrained by inserting a slightly smaller pin into the holes. Commonly two perpendicular components are used to represent the reactive forces.
(3) Draw FBD for entire system
B
G
D
A
FAx
FAy
F
G
E C FC
B F
D
E
A
C
Important Points
Flexible cables can only sustain tensile loadings.
Apply the weight of the body to its center of gravity (if it is uniform, then apply it to the centroid).
Support Reactions and Free-Body Diagrams
Support Reactions and Free-Body Diagrams
Support Reactions Forces acting on a body can be divided into two general categories: reactive forces (or reactions) and applied forces (or active forces). Reactions are those forces that are exerted on a body by its supports. Forces that are not provided by the supports are called applied forces.

工程力学英文版课件13 Deflection of Beams Due to Bending

x M
M ( x) Px
13
Slope and Elastic Curve. Applying equation (4) and integrating twice yields
d w EI 2 Px dx 2 dw Px EI c1 dx 2 Px EIw c1 x c2 6
d w M 2 dx EI
2
(3)
9
If EI is constant, rewriting equation (3), we have 2
d w EI 2 M ( x) dx
(4)
Integrating equation (4) twice yields
dw EI M ( x)dx c1 dx
15
2
3
dw P 2 2 L x dx 2 EI P 3 2 3 w x 3L x 2 L 6 EI
Maximum slope and deflection occur at A (x = 0), for which


PL A 2 EI
2
PL wA 3EI
5
It is important that we should be able to calculate the deflection of a beam of given section, since for given conditions of span and load it would be possible to adopt a section which would meet a strength criterion but would give an unacceptable deflection. The total deflection of a beam is due to a very large extent to the deflection caused by bending, and to a very much smaller extent to the deflection caused by shear.

理论力学第三章 英文ppt


[ mO ( F )] y m y ( F ) m y M Oy [ mO ( F )]z mz ( F ) mz M Oz
The magnitude of the principle moment is
M O ( m x ) 2 ( m y ) 2 ( m z ) 2
If a force system in space is reduced to a given point, we get a resultant force R ' (principle vector )and a resultant couple M O (principle moment). It follows:
In other words, R ' Fi ' Fi (the principle vector R ' passes the point O, and it does not depend on the position of the point O)
4 Composing m1 ,m2 ,mn, we get the principle moment M O ,
R' R' R'
According to the relationship between the moment of the force about a point (O)and the moment of the force about an axis through the point (O) [ mO ( Fi )]x mx ( Fi ) mx M Ox
§3.3 Discussion of the result of the reduction of a force system in space

工程力学专业外语60页PPT


Elastic Range: • Linear elastic: • Nonlinear elastic:
Plastic Range: • Yield point
• Yield strength • Ultimate strength
力学 mechanics 牛顿力学 Newtonian mechanics 经典力学 classical mechanics 静力学 statics 运动学 kinematics 动力学 dynamics 动理学 kinetics 宏观力学 macroscopic mechanics, macromechanics 细观力学 mesomechanics 微观力学 microscopic mechanics, micromechanics 一般力学 general mechanics 固体力学 solid mechanics 流体力学 fluid mechanics 理论力学 theoretical mechanics 应用力学 applied mechanics 工程力学 engineering mechanics 实验力学 experimental mechanics 计算力学 computational mechanics 理性力学 rational mechanics 物理力学 physical mechanics 地球动力学 geodynamics 分析力学 analytical mechanics
1. Stress and strain are related terms used to define the intensity of internal reactive forces in a deformed body and associated unit change of dimension, shape, or volume by externally applied forces.

工程力学专业英语翻译PPT课件

在轴向力作用下，梁的总伸长用希腊字母δ来表示[见图1(a)]， 单位伸长量或者说应变将由方程(2)决定，这里L是指梁的总长度。 注意，这里应变ε是一个无量纲量，只要应变在梁的长度上各处是 均匀的，那么它可以通过方程(2)精确获得。如果梁被拉伸，那么 得到拉应变，表现为材料的延长或者拉伸；如果梁被压缩，那么 得到压应变，意味着梁的横截面将彼此更加靠近。
Note that E has the same units as stress. The modulus of elasticity is sometimes called Young’s modulus, after the English scientist Thomas Young (1773-1829) who studied the elastic behavior of bars. For most materials the modulus of elasticity in compression is the same as in tension.
Eq.(1) can be regarded as the equation for the uniform stress in a prismatic bar. This equation shown that stress has units of force divided by area. When the bar is being stretched by the force P , as shown in the figure, the resulting stress is a tensile stress; if the forces are reversed in direction, causing the bar to be compressed, they are called compressive stress.
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§2–4 Components of a Force Vector §2–5 Rectangular component method
2
§2-1 Graphical Parallelogram Method
Resultant of two concurrent forces
Parallelogram Law Two forces whose lines of action intersect can be replaced by a single force which is the diagonal of a parallelogram that has sides equal to the two forces.
Rx X1 X 2 X 4 X
Ry Y1 Y2 Y3 Y4 Y
Rx Fx Ry Fy
9
The magnitude of the resultant:
R R R
2 x 2 y
F F
2 x y
2
The direction of the resultant:
6
F3 o F2 F4 o R F1
F1
o
F1
F2 R1 F1
R2 o R2
F3 R1
o
F2 R F4
F3
F4
F3
o
F4 R
F2
This resultant force can be found by adding the forces t4 Components of a Force Vector
1
Resultant of Concurrent Forces in a Plane
§2–1 Graphical Parallelogram Method
§2–2 Graphical Triangular Method
§2–3 Resultant of Three or
More Concurrent Forces
5
This resultant force can also be found graphically as the closing side of the polygon of forces constructed as shown in the figure. Thus, the resultant R of any system of concurrent coplanar forces is obtained as the geometric sum of the free vectors representing the given forces.
tg Ry Rx F F
y
∴ tg
1
Ry Rx
tg
1
x
F F
y
x
10
11
cos(180 ) cos
F1 R sin sin( 180 )
4
§2-3 Resultant of Three or More Concurrent Forces
If several coplanar forces F1, F2, …, Fn act at a single point A, they can always be reduced to a resultant force R, which also acts through point A. This resultant force can be found graphically by successive applications of the parallelogram law.
X=Fx=F· cosa Y=Fy=F· sina=F · cos β cosα=Fx/F
sina= cosβ =Fy/F
8
§2-5 Rectangular Components Method
The resultant in x direction Rx and the resultant in y direction Ry are：
Any force F can be replaced by any number of forces whose resultant is F. These replacement forces are called components of the force F. Two components at right angles to each other are the most useful.
3
§2-2 Graphical Triangular Method
Resultant of two concurrent forces Based on parallelogram method
From the law of cosines
R F1 F2 2F1 F2 cos
2 2
From the law of sines