Previous Definition
Finite element analysis is one of the powerful techniques for not only design but also for manufacturing applications. Therefore, FEA has an important role in CIM.
Traditional approach to design analysis involves the application of classical or analytical
techniques. This approach has the following limitations:
i. Stresses and strains are obtained only at macro level. This may result in
inappropriate deployment of materials. Micro level information is necessary to
optimally allocate material to heavily stressed parts.
ii. Adequate information will not be available on critically stressed parts of the
components.
iii. It may be necessary to make several simplifications and assumptions to design
complex components and systems, if design analysis is carried out in the
conventional manner.
iv. Manual design is time consuming and prone to errors.
v. Design optimization is tedious and time consuming.
FEA is a convenient tool to analyze simple as well as complex structures. The use of
finite element analysis is not restricted to mechanical engineering systems alone. FEA finds
extensive application in electrical engineering, electronics engineering, micro electro mechanical systems, biomedical engineering etc. In manufacturing, FEA is used in simulation and optimization of manufacturing processes like casting, machining, plastic molding, forging, metal forming, heat treatment, welding etc. Structural, dynamic, thermal, magnetic potential and fluid flow problems can be handled with ease and accuracy using FEA.
(CAD/CAM/CIM 3.edition, P. Radhakrishnan, S. Subrahmanyan, V. Raju, p.189)
New Definition (Better)
In modern engineering analysis it is rare to find a project that does not require some
type of finite element analysis (FEA). The practical advantages of FEA in stress analysis
and structural dynamics have made it the accepted tool for the last two decades. It is also
heavily employed in thermal analysis, especially for thermal stress analysis.
Clearly, the greatest advantage of FEA is its ability to handle truly arbitrary
geometry. Probably its next most important features are the ability to deal with general
boundary conditions and to include nonhomogeneous and anisotropic materials. These
features alone mean that we can treat systems of arbitrary shape that are made up of
numerous different material regions. Each material could have constant properties or the
properties could vary with spatial location. To these very desirable features we can add a
large amount of freedom in prescribing the loading conditions and in the post-processing
of items such as the stresses and strains. For elliptical boundary value problems the FEA
procedures offer significant computational and storage efficiencies that further enhance its
use. That class of problems include stress analysis, heat conduction, electrical fields,
magnetic fields, ideal fluid flow, etc. FEA also gives us an important solution technique
for other problem classes such as the nonlinear Navier - Stokes equations for fluid
dynamics, and for plasticity in nonlinear solids.
2.Flexible Assembly System (FAS) (Manufacturing)
Previous Definition
A flexible assembly system(FAS) is a fully integrated production system consisting of computer numerically controlled assembly stations, connected by an automated material handling system, all under the control of a central computer
(Tadeusz Sawik, Production planning and scheduling in flexible assembly systems, page1)
New Definition (Better)
Assembly systens generally are set up for a specific product line. However, they can be
modified for increased flexibility in order to assemble product lines that have a variety of
product models. Such flexible assembly systems (FAS) utilize computer controls,
interchangeable and programmable workheads and feedin devices, codded pallets,
and automated guiding devices.
(S. Kalpakjian, S. R. Schmid, Manufacturing Engineering and Technology, p.1182-1183)
3.Continuous System (Assembling)
There is no previous definition.
The product is assembled while moving at a constant speed on pallets or similar workpiece carriers. The parts to be assembled are brought to the product by various workheadsi and their movements are synchronized with the continuous movement of the product. Typical applications of this system are in bottling and packaging plants, although the method also has been used on mass-production lines for automobiles and appliances.
(S. Kalpakjian, S. R. Schmid, Manufacturing Engineering and Technology, p.1182)
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