机械原理英语版

十四、Mechanical principlesDegrees of freedomIn mechanics, degrees of freedom are the set of independent displacements and/or rotations that specify completely the displaced or deformed position and orientation of the body or system.FormulaPl——lower pair , surface contactPh——higher pair , point or line contactn——activity component3——every component have 3 degrees of freedom 2——lower pair have 2 degrees of freedom1——high pair have 1 degrees of freedomF>1 , we can not know what happen next timeF=1 , we can know what happen next timeF=0 , mechanics will not move三审，笔试，有三个图，分别计算哪个结构是稳定的，第一个是稳定的，第二个是稳定但是有过度约束，第三个不稳定可运动。

在过度约束中，审核官问我知道不知道一个公式s=2k-3,我不明白，回来和同学讨论觉得这个应该是计算虚约束的公式，请多注意。

Plane mechanism`s motion analysisInstantaneous center of velocityRevolute pair join, two mechanism , instantaneous center of velocity in center of revolute pair.Rod 1 and rod 2 are combined by revolute pair, P12 is instantaneous center of velocity.Pure-slide pair join, two mechanism , instantaneous center of velocity infinite distance of vertical motion direction.A move along rod B. P12 in infinite distance of vertical rodB .High pair join , two mechanism , they are pure rolling , instantaneous center of velocity in contact point of two mechanism.P12 is instantaneous center of velocityHigher pair join , two mechanism , they are relative slide , instantaneous center of velocity in base tangent.P12 in t-t.Kennedy-Aronhold theoremP13 in P12 and P23 join line. P13 in P14 and P34 join line. P24 in P12 and P14 join line. P24 in P23 and P34 join line.2 and 4 velocity is same in P24Plane four bar mechanismA and D fix called stander , AB CD called side link. Link can rotation called crank--ABLink can shake in range of degree called rocker--CD Crank-rocker mechanismRadarDouble-crank mechanismTrain wheelDouble-rocker mechanismCraneCam mechanismAdvantag e: structure is simple, respond is quickly. Disadvantage: cam produce is difficult, easily wear between cam and follower.GearA gear is a component within a transmission device that transmits rotational force to another gear or device. Spur gearSpur gear are used for low speed applications and those situations where noise control is not a problem.Helical gearHelical gear operate more smoothly than do spur gear. The use of helical gears is indicated when the application involves high speeds , large power transmission or where noise abatement is important,A disadvantage of helical gear is a resultant thrust along the axis of the gear , which needs to be accommodated by appropriate thrust bearing , and a greater degree of sliding friction between the meshing teeth , often addressed with specific additives in the lubricant. Double helical gearsDouble helical gears , also know as herringbone gears , overcome the problem of axis thrust presented by single helical gears by having teeth that set in a "V" shape. Bevel gearThe angle between the shafts can be anything except 0 and 180 degree.Worm gearThe prime feature of a worm-and-gear set is that it allows the attainment of a high gear ratio with few parts in a small space.Rack and pinionTorque cam be converted to linear force by meshing a rack with a pinion : the pinion turns the rack moves in a straight line.Planet gear。

机械原理英语Mechanical Principles in English。

Mechanical principles are the foundation of engineering and technology. Understanding these principles is crucial for anyone working in the field of mechanical engineering. In this document, we will discuss some of the key mechanical principles in English.First and foremost, it is important to understand the concept of force. Force is a vector quantity that can cause an object to accelerate, decelerate, or change direction. It is measured in units of newtons and is represented by the symbol F. The magnitude and direction of a force are essential in determining its effect on an object.Next, let's consider the concept of work and energy. Work is done when a force acts on an object to move it a certain distance. The amount of work done is equal to the force applied multiplied by the distance moved in the direction of the force. Energy, on the other hand, is the ability to do work. There are different forms of energy, including kinetic energy (energy of motion) and potential energy (energy of position).Another important mechanical principle is the study of simple machines. Simple machines are basic mechanical devices that apply a force to accomplish work. The six types of simple machines are the lever, wheel and axle, pulley, inclined plane, wedge, and screw. These simple machines can be combined to create more complex machines that make work easier.Furthermore, it is crucial to understand the concept of mechanical advantage. Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device, or machine system. It is calculated by dividing the output force by the input force. Understanding mechanical advantage is essential for designing and optimizing mechanical systems.Additionally, the study of motion and its principles is fundamental in mechanical engineering. Motion is described in terms of displacement, velocity, and acceleration.The laws of motion, formulated by Sir Isaac Newton, are the foundation of classical mechanics. These laws describe the relationship between the motion of an object and the forces acting on it.Moreover, the study of fluid mechanics is essential in understanding the behavior of fluids (liquids and gases) and their interactions with solid objects. Fluid mechanics plays a crucial role in various engineering applications, including the design of pumps, turbines, and hydraulic systems.In conclusion, the study of mechanical principles in English is essential for anyone working in the field of mechanical engineering. Understanding concepts such as force, work and energy, simple machines, mechanical advantage, motion, and fluid mechanicsis crucial for designing and optimizing mechanical systems. By mastering these principles, engineers can develop innovative solutions to complex engineering problems and contribute to the advancement of technology and society.。

机械原理英语版范文Mechanical PrinciplesIntroductionMechanical principles are the fundamental concepts and laws that govern the behavior and functions of machines and mechanical systems. These principles form the basis of mechanical engineering, providing engineers with the tools and knowledge necessary to design, analyze, and optimize mechanical systems. Understanding mechanical principles is essential for anyone working in the field of mechanical engineering.Newton's Laws of MotionOne of the most fundamental mechanical principles isNewton's laws of motion. These three laws describe the relationship between the motion of objects and the forces acting upon them. The first law states that an object at rest will remain at rest, and an object in motion will continue moving in a straight line at a constant velocity, unless acted upon by an external force. The second law states that the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass. The third law states that for every action, there is an equal and opposite reaction.Mechanical AdvantageFrictionFriction is another important mechanical principle. It is the force that opposes the relative motion of two surfaces in contact with each other. Friction can be both beneficial and detrimental. On one hand, it allows us to walk, drive vehicles, and hold objects without slipping. On the other hand, it causes a loss of energy and wear and tear in mechanical systems. Engineers must take friction into account when designing machines to ensure they function efficiently and reliably.TorqueStress and StrainConclusionThese are just a few of the many mechanical principles that form the foundation of mechanical engineering. By understanding these principles, engineers can design efficient and reliable machines that meet the needs of society. Mechanical engineering continues to advance, with new technologies and principles being discovered and applied every day. The principles discussed here provide a solid starting point for aspiring mechanical engineers to build upon as they delve deeper into the field.。

机械原理英语作文模板英文回答：Mechanical Engineering Principles。

Mechanical engineering principles are the fundamental concepts and laws that govern the behavior of mechanical systems. These principles provide a framework for understanding how machines and devices function, and how to design and analyze them.Some of the most important mechanical engineering principles include:Newton's laws of motion: These laws describe the relationship between an object's mass, velocity, and acceleration. They are essential for understanding how forces affect objects.Energy conservation: This principle states that energycannot be created or destroyed, only transferred or transformed. It is a fundamental principle of physics that applies to all mechanical systems.Momentum conservation: This principle states that the total momentum of a system remains constant, as long as there are no external forces acting on it. It is a fundamental principle of physics that applies to all mechanical systems.Angular momentum conservation: This principle states that the total angular momentum of a system remains constant, as long as there are no external torques acting on it. It is a fundamental principle of physics that applies to all mechanical systems.Elasticity: This property describes the ability of a material to deform under stress and then return to its original shape when the stress is removed. It is an important property for many mechanical systems, such as springs and shock absorbers.Plasticity: This property describes the ability of a material to deform permanently under stress. It is an important property for many mechanical systems, such as metals and polymers.Strength: This property describes the ability of a material to resist deformation or fracture under stress. It is an important property for many mechanical systems, such as beams and columns.Stiffness: This property describes the resistance of a material to deformation under load. It is an important property for many mechanical systems, such as springs and shafts.These are just a few of the many mechanical engineering principles that are used to design and analyze mechanical systems. By understanding these principles, engineers can create machines and devices that are safe, efficient, and reliable.中文回答：机械原理。

机械原理英文经典书籍One classic book on mechanical principles is "Mechanics of Materials" by Ferdinand Beer, E. Russell Johnston, Jr., John DeWolf, and David Mazurek. This book covers the fundamental principles of mechanics, including stress, strain, and deformation of solid materials. It also delves into topics such as axial loading, torsion, bending, and transverse shear. The clear and comprehensive explanations make it a widely used textbook for engineering students and professionals alike.Another widely acclaimed book is "Engineering Mechanics: Dynamics" by J.L. Meriam and L.G. Kraige. This book provides a thorough understanding of the principles of dynamics, including kinematics, kinetics, and energy methods. It covers topics such as particle dynamics, planar kinetics of rigid bodies, and three-dimensional dynamics of rigid bodies. The book also includes numerous real-world examples and applications to help readers grasp the concepts more effectively.In addition, "Machinery's Handbook" by Erik Oberg, Franklin D. Jones, Henry H. Ryffel, and Christopher J.McCauley is a classic reference for mechanical design and engineering. This handbook contains a wealth of information on mechanical principles, formulas, tables, and standards. It covers a wide range of topics, including mathematics, mechanics and strength of materials, properties and treatment of materials, and much more. It is an indispensable tool for mechanical engineers and machinists.Other notable books on mechanical principles include "Theory of Machines and Mechanisms" by John J. Uicker, Gordon R. Pennock, and Joseph E. Shigley, and "Fundamentals of Machine Component Design" by Robert C. Juvinall and Kurt M. Marshek. These books provide in-depth coverage of the principles and applications of machine design, including mechanisms, mechanical systems, and machine components.以上是一些经典的机械原理书籍，它们涵盖了力学、机械设计和材料力学等领域的基本原理和实际应用。

机械原理英文Mechanical Principles。

Mechanical principles are the foundation of many engineering disciplines and are essential for understanding how machines and structures work. These principles are based on the laws of physics and are used to design and analyze mechanical systems. In this document, we will explore the basic principles of mechanics and their applications in engineering.One of the fundamental principles of mechanics is Newton's laws of motion. These laws describe the relationship between the motion of an object and the forces acting on it. The first law states that an object at rest will remain at rest, and an object in motion will remain in motion unless acted upon by an external force. The second law relates the force acting on an object to its mass and acceleration, while the third law states that for every action, there is an equal and opposite reaction.Another important concept in mechanical principles is the study of statics and dynamics. Statics deals with the equilibrium of stationary objects and the forces acting on them, while dynamics focuses on the motion of objects and the forces causing the motion. These principles are crucial for designing stable structures and analyzing the performance of moving components in machines.Mechanical principles also encompass the study of materials and their properties. Understanding the behavior of materials under different conditions is essential for designing reliable and efficient mechanical systems. For example, the strength, stiffness, and ductility of materials determine their suitability for specific applications, and engineers must consider these factors when selecting materials for a design.In addition to the fundamental principles of mechanics, there are various mechanical devices and systems that rely on these principles for their operation. For example, gears, levers, pulleys, and hydraulic systems are all based on mechanical principles and are used in a wide range of applications, from simple machines to complex industrial equipment.The application of mechanical principles is not limited to traditional mechanical engineering disciplines. It also plays a crucial role in fields such as aerospace engineering, automotive engineering, civil engineering, and biomechanics. In aerospace engineering, for instance, the principles of mechanics are used to design aircraft and spacecraft that can withstand the forces of flight and space travel. In automotive engineering, these principles are employed to optimize the performance and safety of vehicles. In civil engineering, they are used to design structures that can withstand various loads and environmental conditions. In biomechanics, mechanical principles are applied to understand the mechanics of the human body and develop medical devices and treatments.In conclusion, mechanical principles are essential for understanding the behavior of machines and structures and are the basis for many engineering disciplines. By studying these principles and their applications, engineers can design innovative and efficient mechanical systems that meet the needs of modern society. Whether it's designing a new machine, developing a new material, or improving an existing system, a solid understanding of mechanical principles is crucial for success in the field of engineering.。

Designing 4 Bar LinkagesStep 1 | Step 2 | Step 3 | Step 4 | JammingIntroduction:This handout will take you through the steps ofdesigning a 4 bar linkage. A four bar linkage isused to define and constrain the motion of an objectto a particular path. The four bars of the linkage areas follows.The Coupler:This is the bar whose motion is beingcontrolled.The Crank:This is the bar connecting the drive source ofthe linkage to the coupler.The Follower:The bar that connect the coupler to thegound.The Ground:The 4th "bar" is the ground or the base of themachine. Even though this does not look likea bar, it functions as one. The follower andcrank (via motor) are both connected to theground.Note: All drawings show both the inital and final positions of linkages.Step 1: Draw Coupler in its Initial and Final PositionsStep 2: Draw ArcsDraw arcs from each mounting point on the output bar. The radius of the arcs should be the same for each mounting hole.Step 3: Draw Locus LinesDraw a pair of lines, one connecting the intersections of each pair of arcs. These lines represent the locus of possible end points for the connecting links.Step 4: Draw Connecting BarsDraw in the connecting bars. There are many possible location for the mounting point on connecting bars. The two figures below show equally valid possibilities for the location of the connecting bars in this example. The initial and final positions of all bars are shown.orTo prevent the linkage from jamming, the mounting point for the connecting bars should not be placed in line with the output bar's mounting hole's initial and final positions. See figure below.。

机械原理英文Mechanical Principles。

Mechanical principles are the foundation of many engineering disciplines, including mechanical engineering, civil engineering, and aerospace engineering. Understanding these principles is essential for designing and analyzing various mechanical systems, from simple machines to complex industrial machinery. In this document, we will explore the key concepts of mechanical principles in English.First and foremost, one of the fundamental principlesin mechanical engineering is the concept of force. Force is a vector quantity that can cause an object to accelerate, decelerate, or change its direction. It is measured inunits of newtons (N) and is represented by arrows in diagrams. The direction of the force vector indicates the direction in which the force is acting, while the length of the arrow represents the magnitude of the force. Understanding the principles of force is crucial foranalyzing the behavior of mechanical systems under various loading conditions.Another important concept in mechanical principles is the study of motion. Motion is the change in position of an object over time and is described using parameters such as displacement, velocity, and acceleration. The laws of motion, as formulated by Sir Isaac Newton, provide the foundation for understanding the behavior of objects in motion. These laws, including the famous second law F=ma, are essential for analyzing the dynamics of mechanical systems and predicting their behavior under different operating conditions.In addition to force and motion, mechanical principles also encompass the study of energy and power. Energy is the ability to do work, and it exists in various forms such as kinetic energy, potential energy, and thermal energy. Understanding the principles of energy is essential for designing efficient mechanical systems and optimizing their performance. Power, on the other hand, is the rate at which work is done or energy is transferred, and it is a keyparameter in the design and operation of mechanical devices.Furthermore, the principles of mechanics also includethe study of materials and their mechanical properties. Materials play a crucial role in the design andconstruction of mechanical systems, and their behaviorunder different loading conditions is essential forensuring the safety and reliability of engineering structures. Understanding concepts such as stress, strain, and elasticity is essential for designing materials thatcan withstand the forces and loads they are subjected to in real-world applications.Moreover, mechanical principles also encompass thestudy of fluid mechanics, which deals with the behavior of fluids (liquids and gases) and the forces acting on them. Understanding the principles of fluid mechanics isessential for designing hydraulic and pneumatic systems, as well as for analyzing the behavior of fluids in various engineering applications.In conclusion, mechanical principles form the basis ofmechanical engineering and are essential for understanding the behavior of mechanical systems. By studying concepts such as force, motion, energy, materials, and fluid mechanics, engineers can design and analyze a wide range of mechanical devices and systems. These principles provide the foundation for solving engineering problems and developing innovative solutions to meet the challenges of the modern world. It is therefore essential for engineering students and practitioners to have a solid understanding of mechanical principles in order to excel in their careers.。