Engineers in each and every industry are utilizing Finite Element Analysis (FEA) in the design cycle to ensure that their products are safe, cost-effective, and fast available in the market. But the analysis is not that simple as putting a CAD model into any FEA package/simulation.
There are more software options today than ever before. For many years, engineers were limited to using linear stress analysis. More recently, finite element packages have been extended to include nonlinear static stress, dynamic stress, fluid flow, heat transfer, electrostatic, FEA-based stress, and motion analysis capabilities. These capabilities are frequently combined to perform analyses that consider multiple physical phenomenons, and are tightly integrated within a CAD interface.
Let us now look at the 3 things all engineers should know before using FEA:
Design Criteria: In any analysis, the engineer needs to determine the significant physical phenomenon and environmental conditions to which the part will be exposed, and also the desired design objective. The first step in the analysis is to determine whether the design will be subject to static or dynamic conditions. In its real-world application, is the part fixed in space, subject to variation, or does it move relative to other parts of the assembly? What happens when you run the entire product through its motion cycle? For years, engineers faced with expensive computing resources have simplified the problem by using static FEA software to calculate stresses at a single instant in time. This method works only if the design does not experience impact, motion, or changes in applied loads over time.
Multiphysics: FEA software often enables engineers to predict other real-world stresses, such as: the effects of extreme temperatures or temperature change (heat transfer analysis), the flow of fluids through and around objects (fluid flow analysis), or voltage distributions over the surface or throughout the volume of an object (electrostatic analysis).
Often these effects work in unison, so it is important that the FEA program can consider their effects on one another. For instance, a computer chip may be heating up over time, cooled down by airflow from a fan, vibrated against other parts, and electrically charged. A typical approach might be to isolate and calculate each variable, then feed the results into the FEA program one at a time. Yet each variable could also affect all the others, so either a coupled analysis or tools for relating results is often necessary.
Modeling: After determining the type of analysis required and the characteristics of the operating environment, the engineer must produce a finite element model with appropriate analysis parameters, such as loads, constraints, and a suitable mesh. The three available methods of CAD/FEA interoperability can vary widely in terms of ease-of-use, accuracy, and functionality.
The CAD universal file format method requires an engineer to export the CAD solid model to a neutral file format, such as IGES, ACIS or Parasolid, and then import the neutral file into the FEA system for setup and analysis. Although this method usually enables engineers to take full advantage of an FEA program, it can also result in the loss of CAD geometry data as the model is translated. So it's not an ideal method, since it sometimes involves using a simplified version of the problem.
The "one window" CAD/FEA method requires no file translation, since the FEA vendor builds analysis capabilities into a CAD solid modeler. Users choose this option for its ease-of-use, as they can access FEA capabilities from a pull-down menu in a single application. However, FEA providers often simplify their one-window versions due to space and interface limitations. In addition, it can also be limited since FEA companies must tailor their product to each CAD vendor's software in order to integrate the two products. So this CAD/FEA interoperability method may require the engineer to purchase and learn other software if he or she is working in a multi-CAD environment or with moderate to advanced analysis capabilities.
The "one window" CAD/FEA method also requires no file translation, but it has the additional capabilities to perform FEA analysis on different computer from CAD solid modeler, and to use a single interface for multiple CAD packages. The primary difference is that FEA runs in a separate application, so an FEA vendor can supply a more complete version without requiring the need for other analysis software. One possible drawback of this approach is that engineer must learn both CAD and FEA software.
Posted by Bhaumik Dave – Sr. FEA Specialist Consultant at HiTech FEA.
There are more software options today than ever before. For many years, engineers were limited to using linear stress analysis. More recently, finite element packages have been extended to include nonlinear static stress, dynamic stress, fluid flow, heat transfer, electrostatic, FEA-based stress, and motion analysis capabilities. These capabilities are frequently combined to perform analyses that consider multiple physical phenomenons, and are tightly integrated within a CAD interface.
Let us now look at the 3 things all engineers should know before using FEA:
Design Criteria: In any analysis, the engineer needs to determine the significant physical phenomenon and environmental conditions to which the part will be exposed, and also the desired design objective. The first step in the analysis is to determine whether the design will be subject to static or dynamic conditions. In its real-world application, is the part fixed in space, subject to variation, or does it move relative to other parts of the assembly? What happens when you run the entire product through its motion cycle? For years, engineers faced with expensive computing resources have simplified the problem by using static FEA software to calculate stresses at a single instant in time. This method works only if the design does not experience impact, motion, or changes in applied loads over time.
Multiphysics: FEA software often enables engineers to predict other real-world stresses, such as: the effects of extreme temperatures or temperature change (heat transfer analysis), the flow of fluids through and around objects (fluid flow analysis), or voltage distributions over the surface or throughout the volume of an object (electrostatic analysis).
Often these effects work in unison, so it is important that the FEA program can consider their effects on one another. For instance, a computer chip may be heating up over time, cooled down by airflow from a fan, vibrated against other parts, and electrically charged. A typical approach might be to isolate and calculate each variable, then feed the results into the FEA program one at a time. Yet each variable could also affect all the others, so either a coupled analysis or tools for relating results is often necessary.
Modeling: After determining the type of analysis required and the characteristics of the operating environment, the engineer must produce a finite element model with appropriate analysis parameters, such as loads, constraints, and a suitable mesh. The three available methods of CAD/FEA interoperability can vary widely in terms of ease-of-use, accuracy, and functionality.
The CAD universal file format method requires an engineer to export the CAD solid model to a neutral file format, such as IGES, ACIS or Parasolid, and then import the neutral file into the FEA system for setup and analysis. Although this method usually enables engineers to take full advantage of an FEA program, it can also result in the loss of CAD geometry data as the model is translated. So it's not an ideal method, since it sometimes involves using a simplified version of the problem.
The "one window" CAD/FEA method requires no file translation, since the FEA vendor builds analysis capabilities into a CAD solid modeler. Users choose this option for its ease-of-use, as they can access FEA capabilities from a pull-down menu in a single application. However, FEA providers often simplify their one-window versions due to space and interface limitations. In addition, it can also be limited since FEA companies must tailor their product to each CAD vendor's software in order to integrate the two products. So this CAD/FEA interoperability method may require the engineer to purchase and learn other software if he or she is working in a multi-CAD environment or with moderate to advanced analysis capabilities.
The "one window" CAD/FEA method also requires no file translation, but it has the additional capabilities to perform FEA analysis on different computer from CAD solid modeler, and to use a single interface for multiple CAD packages. The primary difference is that FEA runs in a separate application, so an FEA vendor can supply a more complete version without requiring the need for other analysis software. One possible drawback of this approach is that engineer must learn both CAD and FEA software.
Posted by Bhaumik Dave – Sr. FEA Specialist Consultant at HiTech FEA.