Finite Element Analysis (FEA) (Other FEA Methods) 1
Minimum Total Potential Energy Formulation/Method After having used the Direct Formulation/Method, the method of minimum potential energy (P.E.) can now be used. 2
FEA One Dimensional Problem Field of Study = Solid Mechanics 4
Theory of Minimum Total P.E. 5
Theory of Minimum Total P.E. 6
Theory of Minimum Total P.E. 7 Here is the general equation for the minimum total P.E.;
Theory of Minimum Total P.E. 8 Example 1.5
Theory of Minimum Total P.E. 9 Now let’s apply the minimum Total P.E. method in Example 1.1
Examples 1.1 10
Bar Under Axial Loading 11
Stiffness Equivalence 12
Preprocessing Phase 13
Minimum Total P.E. Formulation 14
Minimum Total P.E. Formulation 15
Discretization 16
Discretization 17
Free Body Diagram For Each Node 18
Equations and Matrices Derived 19
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Equations and Matrices Derived 21
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Equilibrium 23
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Solution Phase 26
Equations and Matrices Derived 27
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Equations and Matrices Derived 30
Equations and Matrices Derived 31
Postprocessing Phase 32
Equations and Matrices Derived After having obtained the necessary solution in term of nodal displacements, student/researchers may be interesting in obtaining other crucial information e.g., normal stresses, shear stresses, factor of safety, etc. These information are acquired via postprocessing phase. 33
Equations and Matrices Derived OR Let us apply these equations for each element 34
Equations and Matrices Derived 35
Equations and Matrices Derived Let consider again the equilibrium at node 1 to calculate finally the reaction i.e. R1. 36
Equations and Matrices Derived So, the reaction matrix will be as follows: 37