The branch of engineering that deals with design and manufacture of components, devices, machines, and other products. Mechanical engineering is the broadest engineering discipline in terms of the number of industries in which its practitioners and researchers work. Among these industries are agriculture, aerospace, automotive (see illustration), chemical, construction and building services, consumer goods, defense, electronics, food processing, energy (including fuel extraction, conventional power plants, and sustainable energy installations), engineering materials, machinery, manufacturing, and medical devices and instrumentation. See also: Engineering
According to the U.S. Bureau of Labor Statistics, there are approximately 300,000 engineering jobs in the United States. The European Commission, using a different lens, says that the European Union mechanical engineering sector, one of the largest EU industrial sectors, has 3 million employees (not all of them mechanical engineers), working mainly in small family-owned companies.
The primary focus of mechanical engineering is on design. Using fundamental knowledge and concepts, mechanical engineers are engaged in designing components, devices, machines, and other equipment for a wide variety of uses. For example, mechanical engineers design farm machinery that enhances harvests and machinery that improves food handling, storage, and preparation; select lightweight materials for the design of components of automobiles that make them more fuel-efficient; design systems that provide power for the operations of all manner of machines for manufacturing and vehicles for transportation; design prosthetic limbs and medical diagnostic instrumentation; design energy-saving heating, ventilating, and air conditioning (HVAC) systems for commercial buildings, homes, schools, and hospitals; design installations and packaging for large and small computing machinery so that it can operate without breaking down as a result of overheating; design and implement machinery and warehouse systems to make handling packages more efficient. See also: Engineering design; Machine; Machine design; Machinery; Product design
A second key concern of mechanical engineering is on manufacturing. Once assigned the task of developing a new product line, for example, mechanical engineers analyze the intended function of the new product; create a design that will accomplish those functions, which includes selecting appropriate materials in terms of strength, durability, and cost; construct prototypes of the new product and test them; select machinery for manufacturing the products or, when necessary, design and build entirely new machinery, including robots (see illustration) that perform particular operations; create and manage assembly lines; inspect and test finished products; recommend prices for finished goods; and train a sales force. See also: Manufacturing engineering; Production engineering
The initial development of mechanical engineering, spread out over millennia, can be summed up as a history of mechanics and machines. The discipline can be said to have been founded in Mesopotamia, China, and the Greco-Roman civilization, and expanded in the Islamic world in medieval times and in Europe during the Renaissance. The modern development of mechanical engineering, at the dawn of the Industrial Revolution, grew out of needs in agriculture, mining, and textile industries for automation and machines that could replace human labor. Power had to be promoted as a third important area of mechanical engineering, so mechanical engineers could learn how best to generate power, harness it, and use it to make components and machines perform desired functions. The search for improved sources of power—more efficient, more sustainable—continues to this day. See also: Mechanics; Power
The profession of mechanical engineering has evolved dramatically over the past several decades. Computers play a large and growing role in education and in daily work. Increasingly, mechanical engineers have had to become knowledgeable about computer graphics; computer-aided design (CAD), which enables them to design and test components before manufacturing begins; and computerized methods that enable engineers to solve mathematical equations. At one time, mechanical engineers were concerned principally with the fabrication, properties, and behavior of metallic materials. Now, they need to be familiar with polymers, ceramics, carbons, glasses, composites, and numerous advanced materials. Other cutting-edge research and development areas that are increasingly finding applications include nanotechnology, robotics and other advanced manufacturing and materials handling technologies, sustainability initiatives across a broad spectrum of industries, and biomedical projects. Mechanical engineers are encountering demands for balancing technical advancements with moral and ethical considerations. See also: Computer-aided design and manufacturing; Computer graphics; Nanotechnology; Robotics
The first college departments dedicated to training students for mechanical engineering careers were founded in the early 1800s. Since then, mechanical engineering departments have proliferated in institutes centered around scientific and technical education, as well as in more generally based private and publicaly funded colleges and universities, around the world, particularly in North America, the United Kingdom and the rest of Europe, and throughout Asia. Many departments are large in terms of the number of faculty members, and most, if not nearly all, are diverse. Areas of professional expertise and research focus vary widely among faculty members.
Mechanical engineering education starts with grounding in chemistry, physics, mathematics (calculus and differential equations), and computers and computing. The core of a typical mechanical engineering curriculum, emphasizing analysis and design and encouraging innovation, includes courses covering electrical systems, mechanics (statics and dynamics), applied mechanics (strength of materials), dynamics and vibration, mechanical design and fabrication, materials science and engineering, thermodynamics, fluid mechanics, heat transfer, and system dynamics and controls. Courses involving instrumentation and laboratory methods are also typical. Small group projects may be interwoven through many courses. A prominent feature of a typical senior-year curriculum is an industrial design project. In addition, students will be directed toward elective courses aligned with intended areas of professional specialization.
Most mechanical engineering departments offer graduate-level courses as part of advanced degree programs leading to master’s degrees and doctorates. Mechanical engineering societies offer additional educational and professional advancement programs. The two most prominent societies are the American Society of Mechanical Engineers (ASME), which is located in New York City, and The Institution of Mechanical Engineers (IMechE), headquartered in London. Founded in 1880, the ASME, with 100,000-plus members in over 140 countries, trains more than 5000 individuals annually. In addition to maintaining committees that focus on technical areas and holding technical conferences, the ASME provides public courses and publishes Mechanical Engineering magazine, academic journals and books, as well as codes and standards for boilers, elevators, and other engineering installations and components. The IMechE, founded in 1847, has 120,000 members in 140 countries. It maintains a large print and digital engineering library, with books, journals, and databases of materials properties and engineering data and market and company information. The IMechE offers seminars on a wide variety of topics, in addition to in-house training programs, customized for individual engineering sectors, and which can be tailored to the needs of individual organizations.
The mechanical engineering knowledge base is vast. Academic experts and private consultants have proliferated around the world. The mechanical engineering literature has been extensive for a considerable period of time. Many textbooks, manuals, and reference works—including monographs and handbooks—as well as a substantial number of magazines and academic journals are disseminated by numerous commercial publishers and societies, mainly in the United States and Europe. As the world continues to need the services of mechanical engineers, their profession’s core principles and knowledge, nourished by robust research and publishing realms, will enable them to provide advancements through innovation and improvements in dozens of different major fields and subfields useful in numerous industries.