FEMtools 4.5 is a major new version that brings improvements to all FEMtools modules and introduces support for the Optistruct solver. The FE data interfaces and drivers are updated to support the current versions of the FE programs.
The FE data interfaces and drivers are updated to support the current versions of the FE programs:
- MSC Nastran 2024
- Simcenter Nastran V2023.2312 and V2406
- Abaqus 2024
- Ansys 2024R1
- SAP2000 25.3
A new interface and driver is added for Altair OptiStruct (compatible with Nastran). OptiStruct is a simulation technology developed by Altair to solve both linear and nonlinear problems, providing comprehensive solutions for various analyses such as statics, dynamics, vibrations, acoustics, fatigue, and heat transfer. Interfacing with OptiStruct is using the same types of files as with MSC.Nastran and Simcenter Nastran. Bulk data file is used for the FE model data, and binary OP2 files for element matrices and analysis results. The driver for the OptiStruct solver is a variant of the existing Nastran drivers.
CAE, simulation quality assurance, structural dynamics, modal testing, or noise and vibration troubleshooting. The methods shown can be applied to a wide range of industrial applications.
CAE, simulation quality assurance, structural dynamics, modal testing, or noise and vibration troubleshooting. The methods shown can be applied to a wide range of industrial applications.
Common uses for FEMtools can be found in following areas:
- Structural dynamics simulation.
- Test and FE analysis integration.
- Design optimization.
- Uncertainty and probabilistic analysis.
- CAE process integration and automation.
The powerful FEMtools Script language allows for automation, customization and development of additional tools. By developing new scripts, the possible uses for FEMtools for each of the application types are virtually unlimited. Using the FEMtools Scripting language, DDS, customers and partners continuously develop new scripts to extend the range of applications.
If you want to discuss new developments or need assistance with implementing your own, contact DDS or our FEMtools Solutions Partners.
Solutions in Industry
FEMtools is routinely used by companies in many different industries on all continents. Most applications are found in the following industries:
- Aerospace – frames, wings, reaction engines, …
- Automotive/Ground Transportation – Body-in-white, engines, brakes, suspension, power trains, tires, train bogies, frames, …
- Biomechanics – orthopedic implants, prosthetic devices, …
- Civil Engineering – Bridges, dams, buildings, stadiums, piping constructions, …
- Consumer Products/Home appliances – housings, frames, …
- Electronics/Electrical – fans, cover plates, chassis, vibration isolation, semiconductor manufacturing and handling industry, scientific equipment,.
- Government/Defense
- HVAC & Refrigeration
- Industrial equipment/Machinery – paper mills, power generation systems, pumps, gearboxes, turbomachinery, …
- Medical Technology – Bone material identification, dynamic problems in bones and prosthetic devices,
- Marine/Offshore – boats, submarines, oil platforms,
Test-FEA Integration
Integrating test and analysis enables synergistic processes from which the entire engineering team can benefit. Some examples:
- FEA results can be used to optimize the experimental setup (pretest analysis)
- Mixed numerical-analytical methods are used to quickly and reliably identify otherwise only approximately known structural properties (e.g. joint stiffness), material properties, and loading (non-destructive, indirect, testing).
- Test results are used as reference data to validate and refine a finite element model (error localization, correlation analysis, model updating). Unknown or badly known physical properties can be identified and uncertainties in finite element models better assessed.
- Hybrid models that contain partially FE models and partially test models can be developed to build more complete models that include all essential components while maintaining a good balance between model size and performance.
Finite element analysis (FEA) is a powerful technique to support modern engineering practice. Some examples of tasks where FEA can play an important role are
Test new design approaches
Modify an existing design
Solve manufacturing problems
Verify design safety
FEMtools Correlation Analysis is used to correlate reference data with analysis results and to analyze differences. Uncertain parameters are identified and their importance in the analysis assessed.
FEMtools Model Updating is used for running what-if scenarios (sensitivity analysis) and can be applied to improve the quality of the model.
By reading and analyzing results coming from FEA and test, a dedicated working environment like FEMtools is required to support the engineer in a process that is knowledge-based and decision-based.
Structural Health Monitoring and Damage Identification
An updated finite element model reflects the observed dynamic characteristics of the real damaged structure. When this model is compared against a reference model of the undamaged structure, structural changes can be detected, serving as a monitoring, damage detection or QA method. The major tasks in structural health monitoring and damage identification are
- identifying the existence of damage (correlation analysis)
- identifying the location of the damage (error localization, sensitivity analysis)
- estimating the magnitude of the damage (model updating)
- estimating the residual lifetime of the structure
When damage is completely identified, it can be decided to repair the structure or replace it. In practice, damage detection relies not only on error localization methods but also on correlation analysis, sensitivity analysis, model updating, numerical experimentation, simulation of damage patterns etc. This is still an area of extensive research and new methods and procedures are proposed regularly. It is also clear that successful damage detection largely depends on the amount and quality of the test data.
Applications can be found in all kind of industries but particularly in:
- Civil infrastructures: Bridges, highway systems, buildings, power plants, etc.
- Aircraft and missile structures: Helicopters, airplanes, engines, motor cases, etc.
- Space structures: Satellites, space stations, reusable launch vehicles, etc.
- Land/Marine structures: Automobiles, trains, submarines, ships, etc.
- Machinery: rotation machinery, robots, etc.
Material Identification
The finite element model updating method that is implemented in FEMtools can be used for identifying the elastic properties of isotropic, orthotropic and anisotropic materials. If the material properties or beam section properties are selected as global updating parameters, and the modes of vibration of a test specimen (obtained by measurement) are used as reference responses, then the updating procedure will iteratively adjust starting values until predicted dynamic behavior corresponds with observed one.
Modal Pretest Analysis
When a finite element model of a structure is available, then pretest analysis is about using this model to simulate and optimize tests.
Modal pretest analysis provides test engineers with optimal locations and directions to excite the structure, and to position measurement transducers. Modal correlation analysis and finite element model updating considerably benefit from tests that were made using carefully selected sensor locations.
Some questions that can be answered by modal pretest analysis are:
- Find optimal exciter and transducer locations for modal testing
- Create a test model from a reduced finite element model and export in a format readable by modal test packages.
- Determine the directions normal to the surface of curved surfaces from the finite element model and use this information for transforming modal test results in Cartesian coordinates.
- Assess the influence of the accelerometer mass on the model parameters.
- How many modes can be expected in a given frequency range.
Finite Element Mesh Coarsening
Modern structures typically have complex geometries which can require hundreds of thousands of degrees of freedom (DOF). Even relatively simple structures may have bolted or welded connections between members which can be difficult to model without resorting to a fine FE mesh. The computational burden involved in analyzing a model of such large order can be significant. Most FE models make simplifying assumptions about the geometry and connections of a structure in order to keep the order of the model computationally manageable or because the type of simulation only requires a coarse model. For example, the fine density in acoustic analysis is determined from the frequency range of interest.
Structural Design Optimization
Contact us for application cases showing FEMtools Optimization to do:
- Arbitrary nonlinear optimization
- Size optimization (parametric)
- Topometry optimization (shell thickness)
- Topography optimization (beads)
- Shape optimization by mesh morphing
- Topology optimization of plates and solids
- Topology optimization of trusses
- Material optimization
- Design space exploration (variational analysis, design of experiments, response surfaces, …)
Uncertainty and Probabilistic Analysis
Backgrounds
Every finite element analysis is subject to numerous uncertainties. These may be related to the numerical tool itself (discretization, element formulation, solver,…) or to the physics of the problem.
Part of the uncertainty in a FE model can be eliminated or at least reduced by means of prototype testing and model validation and updating, but part of the uncertainty remains. For example the variability of the input parameters due manufacturing processes or environmental conditions may or may not have been taken into account when doing prototype testing.
Uncertainty analysis is finding the relation between given variability and probability on input parameters and the variability and probability of output parameters. With this information, the engineer assesses if the structure is a robust design. Inversely, it is possible to optimize a design to satisfy given constraints on the variability of the responses and thus derive acceptable tolerances on the input parameters. This directly leads to conclusions with respect to manufacturing processes or operating conditions.
Related Tools and Applications
- Monte Carlo sampling.
- Statistical correlation.
- Variability propagation
- Probabilistic model updating.
- Uncertainty classification.
- Robust design.
- Design space exploration.
- Design of experiments.
- Reliability analysis.
- Contact DDS for custom solutions in this area.
CAE Process Integration and Automation
Some examples of CAE process integration and automation applications are:
- Simulation data management.
- Fluid-structure Interaction analysis.
- CAE and CAT pre- and postprocessing (special purpose parametric mesh generators, selective mesh refinement, data visualization,…).
- Postprocessing of test data like scaling, normalization, filtering,…
- Integration with external solvers.
- Using knowledge bases for better FE modeling.
Simulation Data Management
Some type of simulation data management are
- Converting finite element mesh data between different formats
- Backup and archiving
