机械工程
维基百科，自由的百科全书
机械工程是一門涉及利用物理定律為機械系統作分析、設計、生產及維修的工程學科。這學科要求學員對应用力学、热学、物质与能量守恒等基礎科学原理有鞏固的認識，並利用這些知識去分析静态和动态物质系统，创造、设计实用的装置、设备、器材、器件、工具等。機械工程學的知識可應用於汽車、飛機、空調、建築、橋樑、工業儀器及機器等各個層面之上。
目录 |
[编辑] 機械工程的發展
在工業革命以前，大多數的工程項目都限於軍事及城市發展。從事軍事方面的工程師負責研制戰爭工具和系統；從事城市發展的工程師則負責建築和地面設施。在十九世紀早期的英國，機械工程師成為新興的行業，負責提供工業用機械和推動機械所需要的動力。在1818年，首個專業土木工程師組織成立，而機械工程師亦相繼於1847年成立組織。
[编辑] 機械工程教育
[编辑] 基础理论
在美國，機械工程學的課程受到ABET的監管，以保證畢業生對有關項目有最起碼的認知。所以，雖然各家院校所提供的課程內容有異，但一般的機械工程學課程都至少包含以下各個基本科目[1][2]：
- 靜力學及動力學 (statics and dynamics)；
- 剛體力學及材料強度 (solid mechanics and strength of materials)；
- 量度及儀器 (instrumentation and measurement)；
- 熱力學科目 (thermodynamics, heat transfer, energy conversion, and refrigeration/air conditioning)；
- 流體力學及流體動力學 (fluid mechanics/fluid dynamics)；
- 機械設計 (mechanism design, including kinematics and dynamics, engineering design)；
- 生產技術或過程 (manufacturing technology or processes)；
- (hydraulics & pneumatics)；
- mechatronics and/or control theory,
- 工程繪圖、電腦輔助設計(CAD)/電腦輔助生產(CAM)、固體塑模 (Solid Modelling)
至於在大中華地區，機械工程學普遍包括以下各個範疇：
[编辑] Subdisciplines
The field of mechanical engineering can be thought of as a collection of many mechanical disciplines. Several of these subdisciplines which are typically taught at the undergraduate level are listed below, with a brief explanation and the most common application of each. Some of these subdisciplines are unique to mechanical engineering, while others belong to mechanical engineering and one or more other disciplines. Most work that a mechanical engineer does uses skills and techniques from several of these subdisciplines, as well as specialized subdisciplines. Specialized subdisciplines as defined here are usually the subject of graduate more than undergraduate research. Several specialized subdisciplines are discussed at the end of this section 機械工程可以看作是所有機械相關的集合。以下是機械工程系大部分的課程，附有簡短的解說和常見的應用說明。其中有些是機械工程才有的特色。機械工程師多是運用學自這些和其他更專業的課程的方法和技巧。更專業的課程是指研究所的課程，將在這單元的最後討論。
[编辑] 力學
Mechanics is, in the most general sense, the study of forces and their effect upon matter. Typically, engineering mechanics is used to analyze and predict the acceleration and deformation (both elastic and plastic) of objects under known forces (also called loads) or stresses. Subdisciplines of mechanics include
- Statics, the study of non-moving bodies under known loads
- Dynamics (or kinetics), the study of how forces affect moving bodies
- Mechanics of materials, the study of how different materials deform under various types of stress
- Fluid Mechanics, the study of how fluids react to forces. Note that fluid mechanics can be further split into fluid statics and fluid dynamics, and is itself a subdiscipline of continuum mechanics. The application of fluid mechanics in engineering is called hydraulics.
- Continuum mechanics is a method of applying mechanics that assumes that objects are continuous. It is contrasted by discrete mechanics.
Uses
Mechanical engineers typically use mechanics in the design or analysis phases of engineering. If the engineering project were the design of a vehicle, statics might be employed to design the frame of the vehicle, to evaluate where the stresses will be most intense. Dynamics might be used when designing the car's engine, to evaluate the forces in the pistons and cams as the engine cycles. Mechanics of materials might be used to choose an appropriate material for the frame or engine. Fluid mechanics might be used to design a ventilation system for the vehicle (see HVAC), or to design the intake system for the engine.
[编辑] 運動學
運動學是在不考慮作用力的情況下對物體運動進行的研習。 The movement of a crane and the oscillations of a piston in an engine are both simple kinematic systems. The crane is a type of open kinematic chain, while the piston is part of a closed four bar linkage.
應用
Mechanical engineers typically use kinematics in the design and analysis of mechanisms. Kinematics can be used to find the possible range of motion for a given mechanism, or, working in reverse, can be used to design a mechanism that has a desired range of motion.
[编辑] Mechatronics & Robotics
Mechatronics is an interdisciplinary branch of mechanical engineering, electrical engineering and software engineering that is concerned with integrating electrical and mechanical engineering to create hybrid systems. In this way, machines can be automated through the use of electric motors, servo-mechanisms, and other electrical systems in conjunction with special software. A common example of a mechatronics system is a CD-ROM drive. Mechanical systems open and close the drive, spin the CD and move the laser, while an optical system reads the data on the CD and converts it to bits. Integrated software controls the process and communicates the contents of the CD to the computer.
Uses
Mechatronics is currently used in the following areas of engineering:
- Automation, and in the area of robotics.
- Servo-Mechanics
- Sensing and Control Systems
- Automotive engineering, in the design of subsystems such as anti-lock braking systems
- Computer engineering, in the design of mechanisms such as hard drives, CD-ROM drives, etc.
Robotics is the application of mechatronics to create robots, which perform tasks that are dangerous, unpleasant, or repetitive. These robots may be of any shape and size, but all are a) preprogrammed and b) interact physically with the world. To create a robot, an engineer typically employs kinematics (to determine the robot's range of motion) and mechanics (to determine the stresses within the robot).
Uses
Robots are used extensively in Industrial engineering. They allow businesses to save money on labor and perform tasks that are either too dangerous or too precise for humans to perform them economically. Many companies employ assembly lines of robots, and some factories are so reboticized that they can run by themselves. Outside the factory, robots have been employed in bomb disposal, space exploration, and many other fields. Robots are also sold residentially (see Roomba).
[编辑] Structural analysis
Structural analysis or just failure analysis is the branch of mechanical engineering devoted to examining why and how objects fail. Structural failures occur in two general modes: static failure, and fatigue failure. Static structural failure occurs when, upon being loaded (having a force applied) the object being analyzed either breaks or is deformed plastically, depending on the criterion for failure. Fatigue failure occurs when an object fails after a number of repeated loading and unloading cycles. Fatigue failure occurs because of imperfections in the object. A microscopic crack on the surface of the object is one type of imperfection, and it will grow slightly with each cycle (propagation) until the crack is large enough to cause failure.
Failure is not simply defined as when a part breaks, however; it is defined as when a part does not operate as intended. Some systems, such as the perforated top sections of some plastic bags, are designed to break. If these systems do not break, failure analysis might be employed to determine the cause.
Uses
Structural analysis is often used by mechanical engineers after a failure has occurred, or when designing to prevent failure. Engineers may use various books and handbooks such as those published by ASM [1] to aid them in determining the type of failure and possible causes.
Structural analysis may be used the office when designing hardware, in the field to analyze failed parts, or in laboratories where parts might undergo controlled failure tests.
[编辑] Thermodynamics and thermo-science
Thermodynamics is an applied science used in several branches of engineering; including Mechanical Engineering, and Chemical Engineering. At its simplest, thermodynamics is the study of energy, its use and transformation through a system. Typically, engineering thermodynamics is concerned with changing energy from one form to another. As an example, automotive engines, convert chemical energy/enthalpy, from the stored energy in molecules, into heat and then into mechanical work that eventually turns the wheels.
Uses
Thermodynamics principles are used by mechanical engineers in the fields of heat transfer, thermofluids, and energy conversion. Mechanical engineers use thermo-science to design engines and power plants, heating, ventilation, and air-conditioning (HVAC) systems, heat exchangers, heat sinks, radiators, refrigeration, insulation, and others.
[编辑] Drafting
Drafting or technical drawing is the means by which mechanical engineers create instructions for manufacturing parts. A technical drawing can be a computer model or hand-drawn schematic showing all the dimensions necessary to manufacture a part, as well as assembly notes, a list of required materials, and other pertinent information. A U.S. mechanical engineer or skilled worker who creates technical drawings may be referred to as a drafter or draftsman (or, more correctly, draftsperson). Drafting has historically been a two-dimensional process, but recent Computer-Aided Drafting (CAD) programs have begun to allow the designer to create in three dimensions.
Instructions for manufacturing a part must be fed to the necessary machinery, either manually, through programmed instructions, or through the use of a Computer-Aided Manufacturing (CAM) or combined CAD/CAM program. Optionally, an engineer may also manually manufacture a part using the technical drawings, but this is becoming an increasing rarity, except in the areas of applied spray coatings, finishes, and other processes that cannot economically be done by a machine.
Uses
Drafting is used in nearly every subdiscipline of mechanical engineering, and by many other branches of engineering and architecture. Three-dimensional models created using CAD software are also commonly used in Finite element analysis (FEA) and Computational fluid dynamics (CFD).
[编辑] 研究领域
The following is a list of some additional subdisciplines and topics within mechanical engineering. These topics may be considered specialized because they are not typically part of undergraduate mechanical engineering requirements, or require training beyond an undergraduate level to be useful.
- Acoustical Engineering
- 航太工程 (Aerospace Engineering)
- Alternative Energy
- 车辆工程 (Automotive Engineering)
- 汽车理论
- 汽车结构
- 自动化 (Automation)
- 生物工程 (Biomedical Engineering)
- Computer-Aided Engineering
- Heating, Ventilation, and Air Conditioning (HVAC)
- 机械史
- 机械制图
- 机械设计
- 机械制造
- 机械电子
- 納米技術 (Nanotechnology)
- 核子工程 (Nuclear Engineering)
- Piping
- Power Generation
- Engineering Based Programming
- 機械人學 (Robotics)*
- *Robotics is also listed as a general subdiscipline, but because of the breadth of the subject it may require many years of advanced training to be useful to a particular field.
[编辑] Process of Mechanical Engineering
Template:Expand-section
The process of mechanical engineering is optimization: engineers strive to optimize cost, increase productivity, durability, safety, and overall usefulness of objects. This process can be as simple as the design of a chair for comfort or as complex as the optimization of a turbocharged engine for speed. It can be as small as the cutting of a nano-sized gear or as large as the assembly of a supertanker used to carry oil around the world.
[编辑] Tools and Work
Template:Expand-section Modern analysis and design processes in mechanical engineering are aided by various computational tools including FEA, CFD, and CAD/CAM. These modern processes facilitate engineers to model (create a 3D object in a computer), analyze the quality of design etc, before a prototype is created. By this the invention and experimenting with new designs becomes very easy and can be done without any money invested in tooling and prototypes. Simple models can be free and instantaneous, but complicated models, like those describing the mechanics of living tissue, can require years to develop, and the actual computation can be very processor intensive, requiring powerful computers and a lot of cycle time. -->
[编辑] 參考
- ↑ University of Tulsa Required ME Courses - http://www.me.utulsa.edu/Undergraduate.html - Accessed 19 June 2006
- ↑ Harvard Mechanical Engineering Page - http://www.deas.harvard.edu/undergradstudy/engineeringsciences/mechanical/index.html - Accessed 19 June 2006
Format used for web citations: Title - http://link - Notes. Accessed Date.
[编辑] 參看
工程學主題首頁
[编辑] Wikibooks
[编辑] 相關期刊
- Experimental Heat Transfer[2]
- Heat Transfer Engineering[3]
- International Journal for Computational Methods in Engineering Science and Mechanics [4]
- International Journal of Optomechatronics[5]
- Machining Science and Technology[6]
- Materials and Manufacturing Processes[7]
- Mechanics Based Design of Structures and Machines[8]
- Mechanics of Advanced Materials and Structures[9]
- Nanoscale and Microscale Thermophysical Engineering[10]
- Numerical Heat Transfer, Part A[11]
- Numerical Heat Transfer, Part B[12]
- Tribology Transactions[13]
[编辑] 專業團體
- 香港工程師學會 (Hong Kong Institute of Engineering, HKIE)
- ASME (American Society of Mechanical Engineers)
- Pi Tau Sigma (Mechanical Engineering Honor Society)
[编辑] 延伸閱讀
- Burstall，Aubrey F. (1965). A History of Mechanical Engineering，The MIT Press. ISBN 0-262-52001-X.
[编辑] 外部連結
| 類型 |
技術主要領域
|
|
|---|---|---|
| 應用科學 | 人工智慧 | 陶瓷工程 | 計算技術 | 電子學 | 能量 | 儲能技術 | 工程物理 | 綠色科技 | 材料科學 | 微系統技術 | 奈米科技 | 核子技術 | 光學工程 | 量子電腦 | |
| 體育與娛樂 | 露營的裝備 | 遊樂場 | 體育 | 運動設備 | |
| 資訊和通信 | 通信 | 圖畫 | 音樂技術 | 語音識別 | 影像技術 | |
| 產業 | 建築 | 金融工程學 | 製造Aerospace engine業 | 機械 | 採礦業 | |
| 軍事 | 炸彈s | 槍與彈 | 軍事技術與裝備 | 海洋工程 | |
| 住宅 | 家用電器 | 家事技術 | 教育技術 | 食品 | |
| 工程學 | 航太工程 | 農業工程 | 生物工程 | 生化工程 | 生醫工程 | 化學工程 | 土木工程 | 計算機工程 | 電子工程 | 環境工程 | 工業工程學 | 材料科學 | 機械工程 | 冶金學 | 核子工程 | 石油工程 | 軟體工程 | 結構工程學 | 組織工程 | |
| 健康與安全 | 生醫工程 | 生物信息學 | 生物技術 | 化學信息學 | 消防 | 健康科學 | 藥理學 | 安全工程 | |
| 運輸 | 航太 | 航太工程 | 海洋工程 | 機動車 | 太空科技 | 運輸 | |
