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Manufacturing

FEA Automates Analysis

29 Feb, 2004 By: Don LaCourse

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Design simulation and analysis is not just for experts anymore.

The latest crop of FEA (finite-element analysis) tools breaks new ground with MCAD applications. No longer the cryptic, lumbering, budget-busting software of the 1980s, FEA now offers ease of use, tight integration, and a host of simulation and automation features. No, this is definitely not your dad's FEA.

Figure 1. Stress analysis performed on a model of the back cover of a camera. The red areas indicate areas subject to unacceptable stress levels.

To bring us up to date, I've invited Suchit Jain, vice-president of analysis software for SolidWorks Corp. ( www.solidworks.com), to answer some questions about FEA and its emerging use with today's MCAD programs.

Q: Just how easy is it to use FEA?

A: To answer this question, a fitting analogy is the evolution of camera technology. Point, frame, and shoot-this simple three-step process for today's new generation of digital cameras represents a quantum leap forward in ease of use compared with the manual cameras of the past. Those required some expertise to determine what settings to use for shutter speed, aperture, and lens to produce a quality photograph.

Even though just about anyone can use a digital camera, manufacturers offer high-end models that provide sophisticated photographers with the manual controls needed to produce high-quality photos.

Like the camera, FEA was once the domain of specialized analysts. Today, FEA software has become automated and in many cases integrated into CAD applications. COSMOSWorks software, for example, operates inside the SolidWorks mechanical design environment.

Figure 2. You can communicate analysis results with other members of a design team with tools such as SolidWorks eDrawings.

The advanced behind-the-scenes math that drives analysis calculations to simulate design behavior is now fairly mature, and future innovations in FEA will primarily involve advances in ease of use, automation, integration, and communication capabilities.

Some of today's integrated analysis applications are so easy to use that simulating the physical behavior of a design, like taking a digital photo, is a three-step process-model, mesh, and analyze-that gives you a snapshot of a design's physical behavior while maintaining many of the robust capabilities analysts require, such as meshing controls, multiphysics interactions, and element selection to refine analysis results.

Trends toward easy-to-use, integrated FEA software extend the potential benefits that analysis can provide beyond traditional design validation to virtually every phase of product development, from concept development through physical prototyping and production.

Q: What is the historic role of FEA with CAD?

A: Historically, dominant FEA applications have involved failure analysis-using FEA simulations to test performance instead of building costly prototypes or to investigate the cause of field failures. But as FEA technology has grown and advanced-for example, producing color-contoured, animated results instead of a set of numbers that requires interpretation-so has the range of its beneficial applications.

Figure 3. A connecting arm before and after optimization.

Q: How is FEA used with MCAD today?

A: Because analysis software has grown easier to use, more people in product development who are not analysis experts are using it. This is especially true for product designers who create the initial part and assembly models.

By using analysis during the initial design stage, designers not only minimize the probability of failure, but also can leverage analysis results to design better products faster and at lower cost.

Effective product design requires much more than simply creating a geometric shape for a particular function. Designers have to balance a range of design variables and options, from the properties of available materials to size, weight, and loading constraints.

Even if they show only the approximate deflection or stresses instead of the exact results demanded by analysts, quick and easy design analysis results can help designers make prudent decisions at the beginning of the design cycle to minimize problems, delays, and costs later on.

Q: What are the emerging trends in FEA today?

A: In addition to using automated FEA early in the design process, engineers are leveraging integrated analysis software to analyze tooling designs and manufacturing processes to extend tool life, reduce manufacturing steps, improve production processes, and simulate the behavior of full assemblies in an integrated design environment.

Figure 4. CAD/analysis integration lets you enter material properties during the initial modeling stage.

Other trends include the customization of analysis technology to address specific tasks and the adoption of FEA by nontraditional industries. For example, the medical products industry, which historically hasn't used FEA, is increasingly leveraging analysis technology for product development, for example, by using nonlinear analysis to simulate the superelasticity of arterial stents, which must expand and contract dramatically to clear arterial blockages.

Until recently, FEA technology has been packaged as a general-purpose tool that simulates the behavior of just about any type of product design.

Though some analysis applications provide specific physics functionality, such as mechanical, thermal, and CFD (computational fluid dynamics), specialization within each of these areas is increasing and will continue at an accelerated rate. Just as consumers are demanding customization in everything from automobiles to computers, engineers require analysis capabilities that address a narrow range of problems particular to their specific industry.

By focusing analysis technology on specific tasks, such as drop-test analysis for handheld products, cooling analysis for electronics systems design, and multiphysics interaction analysis (mechanical, thermal, and electromagnetic) for MEMS (micro electromechanical systems) design, analysis vendors are pushing advances in ease of use even further.

When addressing specific types of problems, developers of analysis software can leverage interface wizards to automate analysis setup and effectively reduce to a single step what might require several steps with a general-purpose FEA package.

Q:What advice can you offer new FEA users today?

A: Even though analysis automation is making FEA more broadly adopted throughout the product design cycle and across diverse industries, the technology doesn't replace engineering judgment.

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As any analyst knows, putting analysis technology in the hands of an untrained engineer working on mission-critical designs can be dangerous. This is why many FEA training courses focus more on applying analysis and the engineering principles behind the technology rather than just how to use the software's interface.

Analysis packages have reached a level of ease of use where anyone can use them, but applying FEA productively and effectively requires sound engineering judgment and best engineering practices.

This is where analysts can make significant contributions to maximize the benefits of broader FEA use throughout product development. By establishing best practices for engineering and overseeing the use of analysis by designers and engineers, analysts can help product development organizations reduce design cycles and accelerate time to market, while at the same time benefiting from a design-for-analysis foundation.

When engineers use analysis early in the design cycle in an integrated MCAD environment, the analyst's job becomes easier. When best practices are used, all of the information needed to run more complex analyses later is incorporated in the CAD model, enabling analysts to refine results rather than spend time entering setup information, converting models into various data formats, or going through iterations with designers

Today, designers can enter material properties and loading conditions in the initial modeling stage. Analysts can also use APIs (application programming interfaces) to incorporate best practices for their specific products and further automate design analysis. The incorporation of robust tools for communicating design and analysis information also streamlines collaboration between designers and analysts.

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FEA Finale

As FEA makes strides in ease of use, automation, and CAD integration, incorporating it into the product design process can benefit designers, analysts, and the enterprise. For designers, FEA can provide quick and easy snapshots of design performance. For analysts who have more time to use their expertise, FEA can produce refined, highly accurate simulations of design behavior. For the entire product development enterprise, FEA can leverage the design-for-analysis foundation to bring better products to market faster and at lower cost.

Now FEA is as easy as point, frame, and shoot (model, mesh, and analyze). It would make your dad proud-and more than a little envious.