An Overview of Mechanical Engineering
Mechanical Engineering is concerned with the design, manufacture, installation ,and operation of engines and machines and with manufacturing processes. It requires a solid understanding of concepts including mechanics, thermodynamics, and engineering design; as well as solid grounding in physics and math. 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.
History of mechanical engineering
History of mechanical engineering dates to ancient
Greece and China, where mechanisms like screw pumps, steam engines, clocks,
seismometers, and even differential gears were invented. Chain drives,
crankshafts, and camshafts date to the Middle Ages. As a field of engineering
study, however ,mechanical engineering did not start until the advent of the
Industrial Revolution with the demand for the steam engine. The invention of
the steam engine in the latter part of the 18th century gave an enormous
impetus to the development of machines developed, receiving formal recognition
in 1847 in the founding of the Institution of Mechanical Engineers in the
United Kingdom. Mechanical engineering has evolved from the practice by the
mechanic of an art based largely on trial and error to the application by the
professional engineer of the scientific method in research, design, and
production. Since then, advancements in the field of mechanical engineering
have led to such breakthroughs as the internal combustion engine, which made
heavier-than-air powered flight possible and would also lead to the development
of the automoblie, air conditioning ,robotics, and more.
Mechanical engineering subdisciplines
Mechanical engineering is a collection of
many mechanical engineering subdisciplines. Fundamental subjects of mechanical
engineering include:
Mechanics
Mechanics is the physical science that deals
with the state of rest or motion of bodies under forces, It includes specific
topics such as statics and dynamics, strength of materials, solid mechanics,
fluid mechanics/fluid dynamics, hydraulics and pneumatics, and mechanism
design(which includes kinematics).
Mechanics is
used extensively in the design and analysis phases of a project .In vehicle
design, statics will be employed in the design of the frame of the vehicle, in
order to evaluate where and how the stresses will interact .Dynamics might be
used when designing the car's engine ,to evaluate the forces on the pistons and
cams as the engine cycles..Mechanics of materials will be used to choose
appropriate materials for each component of the frame and engine. Fluid
mechanics will be used to design a ventilation system for the vehicle, and
intake system of the engine.
Structural analysis
Structural analysis is devoted to examining
why and how parts 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.
Structural analysis is often used by mechanical engineers after a failure has
occurred, or when designing to prevent failure .It may be used in the office
when designing parts, in the field to analyze failed parts, or in laboratories
where parts might undergo controlled failures tests.
Thermodynamics
Thermodynamics covers topics such as heat
transfer, energy conversion, and refrigeration/air conditioning. it is the
study of the relationship between heat, work, temperature, and energy. In broad
terms, thermodynamics deals with the transfer of energy from one place to
another and from one form to another. The key concept is that heat is a form of
energy corresponding to a definite amount of mechanical work.
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. Drafting has historically been a two-dimensional process, but recent Computer-Aided Designing(CAD)programs have begun to allow the designer to create a part in three dimensions.