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Types of mechanical forces

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A force exerted on a body can cause a change in either the shape or the motion of the body.The unit of force in SI system is the Newton(N) and CGS system is dyne.No solid body is perfectly rigid and when force are applied to it,changes in dimension occur.such changes are not always perceptible to the human eye since they are negligible. For the example,The span of a bridge will sag under the weight of a vehicle and a spanner will bend slightly when tightening a nut. It is also important for civil engineers and designers to appreciate the effects of forces on materials.Together with their mechanical properties of the materials. There three main types of mechanical forces that can act on a body.They are 1)Tensile force 2) compressive force and 3) shear force
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Machining processes

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New Guinea in 1943. Mobile machine shop truck of the US Army with machinists working on automotive parts
Machining is any of various processes in which a piece of raw material is cut into a desired final shape and size by a controlled material-removal process. The processes that have this common theme, controlled material removal, are today collectively known as subtractive manufacturing,[1] in distinction from processes of controlled material addition, which are known as additive manufacturing. Exactly what the "controlled" part of the definition implies can vary, but it almost always implies the use of machine tools (in addition to just power tools and hand tools).
Machining is a part of the manufacture of many metal products, but it can also be used on materials such as wood, plastic, ceramic, and composites.[2] A person who specializes in machining is called a machinist. A room, building, or company where machining is done is called a machine shop. Machining can be a business, a hobby, or both. Much of modern-day machining is carried out by computer numerical control (CNC), in which computers are used to control the movement and operation of the mills, lathes, and other cutting machines.

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