Mechanical engineering is a discipline of
engineering that applies the principles of physics
and materials science for analysis, design,
manufacturing, and maintenance of mechanical
systems. It is the branch of engineering that
involves the production and usage of heat and
mechanical power for the design, production, and
operation of machines and tools. [1] It is one of the
oldest and broadest engineering disciplines.
The engineering field requires an understanding of
core concepts including mechanics , kinematics ,
thermodynamics, materials science, and structural
analysis. Mechanical engineers use these core
principles along with tools like computer-aided
engineering and product lifecycle management to
design and analyze manufacturing plants, industrial
equipment and machinery, heating and cooling
systems, transport systems, aircraft , watercraft,
robotics, medical devices and more.
Mechanical engineering emerged as a field during
the industrial revolution in Europe in the 18th
century; however, its development can be traced
back several thousand years around the world.
Mechanical engineering science emerged in the
19th century as a result of developments in the
field of physics. The field has continually evolved to
incorporate advancements in technology, and
mechanical engineers today are pursuing
developments in such fields as composites,
mechatronics, and nanotechnology. Mechanical
engineering overlaps with aerospace engineering,
civil engineering, electrical engineering, petroleum
engineering, and chemical engineering to varying
amounts.
Degrees in mechanical engineering are offered at
universities worldwide. In Brazil, Ireland, China,
Greece, Turkey, North America, South Asia, and
the United Kingdom, mechanical engineering
programs typically take four to five years of study
and result in a Bachelor of Science (B.Sc),
Bachelor of Science Engineering (B.ScEng),
Bachelor of Engineering (B.Eng), Bachelor of
Technology (B.Tech), or Bachelor of Applied
Science (B.A.Sc) degree, in or with emphasis in
mechanical engineering. In Spain, Portugal and
most of South America, where neither BSc nor
BTech programs have been adopted, the formal
name for the degree is "Mechanical Engineer", and
the course work is based on five or six years of
training. In Italy the course work is based on five
years of training, but in order to qualify as an
Engineer you have to pass a state exam at the end
of the course.
In Australia, mechanical engineering degrees are
awarded as Bachelor of Engineering (Mechanical).
The degree takes four years of full time study to
achieve. To ensure quality in engineering degrees,
the Australian Institution of Engineers accredits
engineering degrees awarded by Australian
universities. Before the degree can be awarded,
the student must complete at least 3 months of on
the job work experience in an engineering firm.
In the United States, most undergraduate
mechanical engineering programs are accredited
by the Accreditation Board for Engineering and
Technology (ABET) to ensure similar course
requirements and standards among universities.
The ABET web site lists 276 accredited mechanical
engineering programs as of June 19, 2006. [9]
Mechanical engineering programs in Canada are
accredited by the Canadian Engineering
Accreditation Board (CEAB), [10] and most other
countries offering engineering degrees have similar
accreditation societies.
Some mechanical engineers go on to pursue a
postgraduate degree such as a Master of
Engineering, Master of Technology, Master of
Science, Master of Engineering Management
(MEng.Mgt or MEM), a Doctor of Philosophy in
engineering (EngD, PhD) or an engineer's degree.
The master's and engineer's degrees may or may
not include research. The Doctor of Philosophy
includes a significant research component and is
often viewed as the entry point to academia.[11]
The Engineer's degree exists at a few institutions
at an intermediate level between the master's
degree and the doctorate.
Standards set by each country's accreditation
society are intended to provide uniformity in
fundamental subject material, promote competence
among graduating engineers, and to maintain
confidence in the engineering profession as a
whole. Engineering programs in the U.S., for
example, are required by ABET to show that their
students can "work professionally in both thermal
and mechanical systems areas." [12] The specific
courses required to graduate, however, may differ
from program to program. Universities and
Institutes of technology will often combine multiple
subjects into a single class or split a subject into
multiple classes, depending on the faculty available
and the university's major area(s) of research.
The fundamental subjects of mechanical
engineering usually include:
Statics and dynamics
Strength of materials and solid
mechanics
Instrumentation and
measurement
Electrotechnology
Electronics
Thermodynamics, heat transfer ,
energy conversion , and HVAC
Fluid mechanics and fluid
dynamics
Mechanism design (including
kinematics and dynamics )
Manufacturing engineering,
technology, or processes
Hydraulics and pneumatics
Mathematics - in particular,
calculus, differential equations,
and linear algebra .
Engineering design
Product design
Mechatronics and control theory
Material Engineering
Design engineering, Drafting,
computer-aided design (CAD)
(including solid modeling ), and
computer-aided manufacturing
(CAM) [13][14]
Mechanical engineers are also expected to
understand and be able to apply basic concepts
from chemistry, physics, chemical engineering,
civil engineering, and electrical engineering. Most
mechanical engineering programs include multiple
semesters of calculus, as well as advanced
mathematical concepts including differential
equations, partial differential equations, linear
algebra , abstract algebra , and differential
geometry, among others.
In addition to the core mechanical engineering
curriculum, many mechanical engineering
programs offer more specialized programs and
classes, such as robotics, transport and logistics ,
cryogenics, fuel technology, automotive
engineering, biomechanics , vibration , optics and
others, if a separate department does not exist for
these subjects. [15]
Most mechanical engineering programs also
require varying amounts of research or community
projects to gain practical problem-solving
experience. In the United States it is common for
mechanical engineering students to complete one
or more internships while studying, though this is
not typically mandated by the university.
Cooperative education is another option.
The total number of engineers employed in the U.S.
in 2009 was roughly 1.6 million. Of these, 239,000
were mechanical engineers (14.9%), the second
largest discipline by size behind civil (278,000).
The total number of mechanical engineering jobs in
2009 was projected to grow 6% over the next
decade, with average starting salaries being
$58,800 with a bachelor's degree. [19] The median
annual income of mechanical engineers in the U.S.
workforce was roughly $74,900. This number was
highest when working for the government
($86,250), and lowest in education ($63,050). [20]
In 2007, Canadian engineers made an average of
CAD$29.83 per hour with 4% unemployed. The
average for all occupations was $18.07 per hour
with 7% unemployed. Twelve percent of these
engineers were self-employed, and since 1997 the
proportion of female engineers had risen to 6%.
An oblique view of a four-cylinder inline
crankshaft with pistons
Many mechanical engineering companies,
especially those in industrialized nations, have
begun to incorporate computer-aided engineering
(CAE) programs into their existing design and
analysis processes, including 2D and 3D solid
modeling computer-aided design (CAD). This
method has many benefits, including easier and
more exhaustive visualization of products, the
ability to create virtual assemblies of parts, and the
ease of use in designing mating interfaces and
tolerances.
Other CAE programs commonly used by
mechanical engineers include product lifecycle
management (PLM) tools and analysis tools used
to perform complex simulations. Analysis tools
may be used to predict product response to
expected loads, including fatigue life and
manufacturability. These tools include finite
element analysis (FEA), computational fluid
dynamics (CFD), and computer-aided
manufacturing (CAM).
Using CAE programs, a mechanical design team
can quickly and cheaply iterate the design process
to develop a product that better meets cost,
performance, and other constraints. No physical
prototype need be created until the design nears
completion, allowing hundreds or thousands of
designs to be evaluated, instead of a relative few.
In addition, CAE analysis programs can model
complicated physical phenomena which cannot be
solved by hand, such as viscoelasticity, complex
contact between mating parts, or non-Newtonian
flows
As mechanical engineering begins to merge with
other disciplines, as seen in mechatronics,
multidisciplinary design optimization (MDO) is
being used with other CAE programs to automate
and improve the iterative design process. MDO
tools wrap around existing CAE processes,
allowing product evaluation to continue even after
the analyst goes home for the day. They also
utilize sophisticated optimization algorithms to
more intelligently explore possible designs, often
finding better, innovative solutions to difficult
multidisciplinary design problems.
SOURCE:http://en.wikipedia.org/wiki/
Mechanical_engineering
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