Guidelines for FEA shoppers

List your needs, calculate an ROI, and be leery of canned demos. According to expert users of finite-element software, there are several telltale signs that a company needs to get on the FEA bandwagon. One is when design cycles grow too short to comfortably finish projects, or when they turn away business because they cannot meet deadlines. "Or, if your company builds special machines in low quantities," says James Perrault, an MSC.Nastran user and engineering manager with ) in Tulsa. "There is not a lot of time to go through several designs to get it right. Another indicator is when stress studies based on simple equations or Roark's formulas for stress and strain are an oversimplification. Then you need to turn to FEA." Once a department accepts that design schedules are tolerable only if they can do more in less time, they must decide which FEA program is right for them. In a nutshell, our experts pinpointed ease-of-use, accuracy, cost, speed, and support as key issues with FEA software. More specifically, they suggest first deciding what analysis makes sense . For example, if a department does a lot of straightforward stress studies, then a program with linear-static capability is a candidate. Most basic FEA programs provide this along with modal or vibration analysis, and buckling. Thermal analysis may be included as well. Of course, if products involve fluid flow, then contact software developers that specialize in CFD or computational fluid dynamics. "Ask the salesperson if they sell something tailored to what you do," suggests Rob Calvet, an Algor user and senior optomechanical engineer with ). Software companies are starting to formulate products modularly. This way, users buy only what they need. When faced with new tasks, they merely add another module. "And ask whether or not the modules work together," he