Probabilistic Finite Element System (ProFES)
The Probabilistic Finite Element System (ProFES) application was developed by the Computational Mechanics Group of ARA's Southeast Division located in Raleigh, NC. ProFES allows you to quickly develop probabilistic models from your own model executables, analytical formulations, or finite element models. ProFES can be used in many ways, such as independently performing probabilistic simulations using functions internal to ProFES or functions that you manually type in, an add-on to your own model executables so you can perform probabilistic studies from your deterministic models, an add-on to the commercial finite element codes ANSYS and NASTRAN or to the commercial CAD package PATRAN, and you can assess the uncertainty inherent in any design or analysis situation and relate this uncertainty to product failure rates.
The ProFES GUI is designed to make it easy to perform probabilistic analyses, especially for non-experts. Random variables can be assigned to any of the variables that make up your analytical model or that are input to your model executable. In the case of finite element analyses, random variables can be assigned to loads, material properties, element properties, and boundary conditions. In the case of CAD analyses, as is the case with PATRAN, random variables can also be given to geometry features (in our case, the features are obtained by importing Unigraphics parts into PATRAN). Failure criteria (limit-states) are used to define failure as a function of your model results (e.g., output variables from your own models, displacements, strains, stresses, etc.). ProFES also includes utilities for seamlessly postprocessing your results (e.g., for probabilistic fatigue analysis). ProFES provides a library of random variables and utilizes state-of-the-art probabilistic analysis methods.
Probabilistic finite element analysis has advanced to the point that specialists can solve very complex problems. Computational methods for probabilistic mechanics are well developed and widely available, including FORM/SORM methods, static and adaptive response surface methods, simulation methods, and adaptive importance sampling.
ProFES places these tools in the hands of practitioners and makes them usable without extensive re-training and software development. ProFES includes an innovative data-driven architecture that has the look and feel of commercial CAD and pre-processing packages. The ProFES approach supports transparent interfaces to commercially available finite element packages and allows you to build your deterministic model in your preferred commercial pre-processing package. ProFES has been integrated with several major probabilistic computational methods along with an extensive library of random variable distributions.
ProFES is designed to work with commercially available finite element software. If your finite element software is not ANSYS or NASTRAN, you will write your own interface between your finite element software and ProFES by following a documented procedure.
There are five steps to performing probabilistic analysis:
- Import a finite element model
- Define the random variables
- Describe the failure criteria or limit state functions
- Run the analysis
- Review the results
Applied Research Associates, Probabilistic Mechanics Group
8537 Six Forks Road, Suite 600, Raleigh, NC 27615
Phone: (919) 582-3300 | ProFES@ara.com