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Design and drafting
Drafting or technical drawing is the means by which mechanical engineers design products and 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. Drafting has historically been a two-dimensional process, but computer-aided design (CAD) programs now 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 acomputer-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, with the advent of computer numerically controlled (CNC) manufacturing. Engineers primarily manually manufacture parts in the areas of applied spray coatings, finishes, and other processes that cannot economically or practically be done by a machine.
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).
Frontiers of research
Mechanical engineers are constantly pushing the boundaries of what is physically possible in order to produce safer, cheaper, and more efficient machines and mechanical systems. Some technologies at the cutting edge of mechanical engineering are listed below (see also exploratory engineering).
[Micro electro-mechanical systems (MEMS)
Micron-scale mechanical components such as springs, gears, fluidic and heat transfer devices are fabricated from a variety of substrate materials such as silicon, glass and polymers like SU8. Examples of MEMS components are the accelerometers that are used as car airbag sensors, modern cell phones, gyroscopes for precise positioning and microfluidic devices used in biomedical applications.
Friction stir welding (FSW)
Main article: Friction stir welding
Friction stir welding, a new type of welding, was discovered in 1991 by The Welding Institute (TWI). The innovative steady state (non-fusion) welding technique joins materials previously un-weldable, including several aluminum alloys. It plays an important role in the future construction of airplanes, potentially replacing rivets. Current uses of this technology to date include welding the seams of the aluminum main Space Shuttle external tank, Orion Crew Vehicle test article, Boeing Delta II and Delta IV Expendable Launch Vehicles and the SpaceX Falcon 1 rocket, armor plating for amphibious assault ships, and welding the wings and fuselage panels of the new Eclipse 500 aircraft from Eclipse Aviation among an increasingly growing pool of uses.[27][28][29]
Composites
Composites or composite materials are a combination of materials which provide different physical characteristics than either material separately. Composite material research within mechanical engineering typically focuses on designing (and, subsequently, finding applications for) stronger or more rigid materials while attempting to reduce weight, susceptibility to corrosion, and other undesirable factors. Carbon fiber reinforced composites, for instance, have been used in such diverse applications as spacecraft and fishing rods.
Mechatronics
Main article: Mechatronics
Mechatronics is the synergistic combination of mechanical engineering, Electronic Engineering, and software engineering. The purpose of this interdisciplinary engineering field is the study of automation from an engineering perspective and serves the purposes of controlling advanced hybrid systems.
Nanotechnology
Main article: Nanotechnology
At the smallest scales, mechanical engineering becomes nanotechnology —one speculative goal of which is to create a molecular assembler to build molecules and materials viamechanosynthesis. For now that goal remains within exploratory engineering. Areas of current mechanical engineering research in nanotechnology include nanofilters,[30] nanofilms,[31] and nanostructures,[32] among others.
Finite element analysis
Main article: Finite element analysis
This field is not new, as the basis of Finite Element Analysis (FEA) or Finite Element Method (FEM) dates back to 1941. But evolution of computers has made FEA/FEM a viable option for analysis of structural problems. Many commercial codes such as ANSYS, Nastran and ABAQUS are widely used in industry for research and design of components. Calculix is an open source and free finite element program. Some 3D modeling and CAD software packages have added FEA modules.
Other techniques such as finite difference method (FDM) and finite-volume method (FVM) are employed to solve problems relating heat and mass transfer, fluid flows, fluid surface interaction etc.
Biomechanics
Main article: Biomechanics
Biomechanics is the application of mechanical principles to biological systems, such as humans, animals, plants, organs, and cells.[33]
Biomechanics is closely related to engineering, because it often uses traditional engineering sciences to analyse biological systems. Some simple applications of Newtonian mechanics and/ormaterials sciences can supply correct approximations to the mechanics of many biological systems.
Computational fluid dynamics
Main article: Computational fluid dynamics
Computational fluid dynamics, usually abbreviated as CFD, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with surfaces defined by boundary conditions. With high-speed supercomputers, better solutions can be achieved. Ongoing research yields software that improves the accuracy and speed of complex simulation scenarios such as transonic or turbulent flows. Initial validation of such software is performed using a wind tunnel with the final validation coming in full-scale testing, e.g. flight tests.
Related fields
Manufacturing engineering and Aerospace Engineering are sometimes grouped with mechanical engineering. A bachelor's degree in these areas will typically have a difference of a few specialized classes.
Notes and references
1. ^ engineering "mechanical engineering. (n.d.)". The American Heritage Dictionary of the English Language, Fourth Edition. Retrieved: May 8, 2010.
2. ^ "Heron of Alexandria". Encyclopedia Britannica 2010 - Encyclopedia Britannica Online. Accessed: 09 May 2010.
4. ^ Al-Jazarí. The Book of Knowledge of Ingenious Mechanical Devices: Kitáb fí ma'rifat al-hiyal al-handasiyya. Springer, 1973. ISBN 90-277-0329-9.
6. ^ R. A. Buchanan. The Economic History Review, New Series, Vol. 38, No. 1 (Feb., 1985), pp. 42–60.
11. ^ Accredited engineering programs in Canada by the Canadian Council of Professional Engineers, Accessed April 18, 2007.
14. ^ University of Tulsa Required ME Courses - Undergraduate Majors and Minors. Department of Mechanical Engineering, University of Tulsa, 2010. Accessed: 17 December 2010.
18. ^ [2] Aalto University School of Engineering, Design Factory - Researchers Blog, Accessed November 5, 2012.
21. ^ "Codes of Ethics and Conduct". Online Ethics Center. Archived from the original on June 19, 2005. Retrieved July 24, 2005.
22. ^ 2010-11 Edition, Engineers - Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, Accessed: 9 May 2010.
25. ^ Note: 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 and pneumatics.
26. ^ ASM International's site containing more than 20,000 searchable documents, including articles from the ASM Handbook series and Advanced Materials & Processes
30. ^ Nilsen, Kyle. (2011) "Development of Low Pressure Filter Testing Vessel and Analysis of Electrospun Nanofiber Membranes for Water Treatment"
31. ^ Mechanical Characterization of Aluminium Nanofilms, Microelectronic Engineering, Volume 88, Issue 5, May 2011, pp. 844–847.
32. ^ http://www.cise.columbia.edu/nsec/ Columbia University and National Science Foundation, Accessed June 20, 2012.
33. ^ R. McNeill Alexander (2005) Mechanics of animal movement, Current Biology Volume 15, Issue 16, 23 August 2005, Pages R616-R619
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