Page 18 - Using ANSYS for Finite Element Analysis A Tutorial for Engineers
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IntroductIon to FInIte element AnAlysIs   •   5
                      1.1.3  a Brief history of feM


                      Finite element analysis (FEA) was first developed in 1943 by R.  Courant,
                      who utilized  the Ritz method of numerical  analysis and minimization
                      of variational calculus to obtain approximate solutions to vibration
                      systems. Shortly thereafter, a paper published in 1956 by M. J. Turner,
                      R. W. Clough, H. C. Martin, and L. J. Topp established a broader definition
                      of numerical analysis. The paper centered on the “stiffness and deflection
                      of complex structures.”
                          By the early 1970s, FEA was limited to expensive mainframe com-
                      puters generally  owned by the aeronautics,  automotive,  defense, and
                      nuclear industries. Since the rapid decline in the cost of computers and the
                      phenomenal increase in computing power, FEA has been developed to an
                      incredible precision. Present day super computers are now able to produce
                      accurate results for all kinds of parameters.


                      1.1.4  the feM analysis Process

                      A model-based simulation process using FEM consists of a sequence of
                      steps.  This  sequence  takes  two  basic  configurations  depending  on  the
                      environment in which FEM is used. These are referred to as the mathe-
                      matical FEM and the physical FEM.
                          The mathematical FEM as depicted in Figure 1.4, the centerpiece in
                      the process steps of the mathematical FEM is the mathematical mode,
                      which is often an ordinary or partial differential equation in space and
                      time. Using the methods provided by the variational calculus, a discrete
                      finite  element  model  is  generated  from  the  mathematical  model.  The
                      resulting  FEM equations  are processed by an equation  solver, which
                      provides a  discrete  solution.  In this  process, we may  also think of an
                      ideal  physical  system,  which may be regarded  as a realization  of the
                        mathematical  model.  For example,  if  the  mathematical  model  is  the

                                                                  Verification
                                               Mathematical  discretization + solution error
                                                  model
                                              FEM
                             Physical         Complicated model Solution  Discrete
                             problem                             solution
                                                        Verification
                                                       solution error


                       Figure 1.4.  The mathematical FEM.
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