Finite Element Analysis (FEA) is a tool used for the evaluation of structures and systems, providing an accurate prediction
of a component's response subjected to thermal and structural loads. Structural analyses include
all types of steady or cyclic loads, mechanical or thermal, along with non-linearities, such as opening/closing of contact surfaces, and
non-linear material behavior. Thermal analyses include convection, conduction, and radiation heat transfer, as well as various thermal transients and thermal shocks.
FEA is used to analyze complex geometries, whereas very simple ones (for example, a beam) can be analyzed using hand calculations. For a structure subjected to
a load condition (thermal, mechanical, vibratory, etc.) its response (deflection, stress, etc.) can be predicted and measured against
acceptable defined limits. In the most simplest terms, this is a factor of safety, which is the ratio of the stress in a component,
to the allowable stress of the material. If a factor of safety is too small, the possibility of failure becomes unacceptably large; on
the other hand, if the factor is unneccesarily large, the result is a uneconomical or nonfunctional design. For the majority of structural
and machine applications, factors if safety are specified by design specifications or codes written by committees of experienced engineers,
such as the American Institute of Steel Construction (design & construction of structural steel for buildings) and the American Concrete Institute (building codes requirements for reinforced concrete).
| The analysis is done by modeling the structure into thousands of small pieces (finite elements). Breaking the entire structure into such small peices or "elements" is called discretization. The solution to the governing equations is closely approximated within each element, resulting in a number of equations that need to be solved for every element. However, each element interacts with its neighbors, i.e., each element's response tightly depends on that of its neighbors, and the responses of their neighbors to those of other neighbors, and so forth. |
Thus, the element equations cannot be solved alone to render the solution over
each element. Instead, all the equations from all the elements over the
entire structure need to be solved simultaneously. This task can only
be performed by computers. It is noteworthy that, as the structure is
broken into a larger number of elements, a greater number of simultaneous
equations need to be solved. Thus, typically, results for more complex
structures require more computing power.
FEA was largely developed in the 1950's by aerospace engineers to design better
aircraft structures. Since then, aided by the rapid growth of computing
power, the method has continually developed, and is now the tool of choice
for technical analysis by mechanical, civil, biomechanical, and other
engineers.
- It is a very accurate tool used for failure analysis purposes.
- Used to quantify design defects, fatigue, buckling, and code compliance.
- Can be used to distinguish between failures due to design deficiencies, materials defects, fabrication errors, and abusive use.
- It provides quantified results previously based on metallurgical and mechanical testing.
- It provides excellent visual aids and animations easily understood by juries.
Historical Note: Early FEA code development followed hardware progress. ANSYS was first released in 1970, running on $1,000,000 CDC, Univac, and IBM mainframe computers which were much less powerful than today's PC's. A Pentium PC could solve that 5,000 x 5,00 matrix system in a few minutes, instead of days as in the past.
We have successfully used finite element analysis in State, Federal, and International courts. For a description of our sample cases, see Portfolio. To discuss your technical issues, please Contact Us.