Page 16 - Finite Element Modeling and Simulations with ANSYS Workbench

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Introduction

1.1 Some Basic Concepts
The finite element method (FEM), or finite element analysis (FEA), is based on the idea of
building a complicated object with simple blocks, or, dividing a complicated object into
smaller and manageable pieces. Application of this simple idea can be found everywhere
in everyday life (Figure 1.1), as well as in engineering. For example, children play with
®
LEGO toys by using many small pieces, each of very simple geometry, to build vari-
ous objects such as trains, ships, or buildings. With more and more smaller pieces, these
objects will look more realistic.
In mathematical terms, this is simply the use of the limit concept, that is, to approach or
represent a smooth object with a finite number of simple pieces and increasing the number
of such pieces in order to improve the accuracy of this representation.

1.1.1 Why FEA?
Computers have revolutionized the practice of engineering. Design of a product that used
to be done by tedious hand drawings has been replaced by computer-aided design (CAD)
using computer graphics. Analysis of a design used to be done by hand calculations and
many of the testing have been replaced by computer simulations using computer-aided
engineering (CAE) software. Together, CAD, CAE, and computer-aided manufacturing
(CAM) have dramatically changed the landscape of engineering (Figure 1.2). For example,
a car, that used to take five to six years from design to product, can now be produced start-
ing from the concept design to the manufacturing within a year using the CAD/CAE/
CAM technologies.
Among all the computational tools for CAE, the FEM is the most widely applied method
or one of the most powerful modern “calculators” available for engineering students and
professionals. FEA provides a way of virtually testing a product design. It helps users
understand their designs and implement appropriate design changes early in the product
development process. The adoption of FEA in the design cycle is driven by market pres-
sure since it brings many benefits that will help companies make better products with
reduced development costs and time-to-market.

1.1.2 Finite Element Applications in Engineering
The FEM can be applied in solving the mathematical models of many engineering prob-
lems, from stress analysis of truss and frame structures or complicated machines, to
dynamic responses of automobiles, trains, or airplanes under different mechanical,

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