Finite Element Analysis is a computerized numerical analysis method that can be used to solve complex problems and is the dominant method used today. As the name implies, it takes a complex problem and breaks it down into a finite number of simple problems. A continuous structure theoretically has an infinite number of simple problems, but finite element analysis approximates the behavior of a continuous structure by analyzing a finite number of simple problems. Each element in a finite element analysis is one of these simple problems. Each element in a finite element model will have a fixed number of points, or nodes, that define the element boundaries to which loads and boundary conditions (force, temperature, pressure, velocity, acceleration, etc) can be applied. The finer the mesh, the closer we can approximate the geometry of the structure, the load application, as well as the stress and strain gradients for example, assuming that the problem we are solving is of a structural nature. Finite element analysis can be used to solve a wide range of problems from structural stress, heat transfer, thermal stress, flow simulations, etc. to the more unusual like electromagnetic field simulations. Virtually any environment can be simulated.
With all of these applications there is a tradeoff: the finer the mesh, the more computational power is needed to solve the complex problem. The strategy of optimizing the mesh size or mesh density can greatly reduce an analyst’s time without compromising on the quality of analysis results. This is where practical experience is needed. A good analyst will be able to construct a FEA model that concentrates the finer mesh in the areas where the highest stress, heat flow, pressure, etc. exists, permitting quick solutions to what would otherwise take a long computation time to complete.
The results can be used to verify the design integrity and expose areas that are too weak, too strong, too hot, cold, etc. without having to build the part or assembly. When the analyst combines experience with design, testing and manufacturing, much shorter design cycles are the result along with a more robust product.
Some of the tools I have used are as follows:
ANSYS multiphysics
ANSYS explicit dynamics and LS Dyna (impact analysis)
ANSYS Fluent (CFD)
ANSYS CFX (CFD)
ANSYS Mechanical (structural and stress analysis, fatigue and vibration analysis)
Norman T. Neher, P.E.
Analytical Engineering Services, Inc.
Elko New Market, MN
www.aesmn.org