Detailed models shorten time from design to production.

Back in the 1970s, when the CEO of a major aircraft manufacturer proudly announced that his company had produced a virtual model of an aircraft fuselage, he was referring only to the geometry of the fuselage. The model didn’t include the aerodynamics for calculating the air flow patterns over the wings and fuselage because the technology simply wasn’t sophisticated enough. Simulations at that time had only about 5,000 degrees of freedom – or independent parameters for modeling.

Contrast that to the capabilities of current models. “In today’s world, we literally model with millions of degrees of freedom, so that we can make the virtual twin look almost exactly like the real thing to the extent that you put all the physics in the simulation and modeling,” says Byron Pipes, an engineering professor at Purdue University and the director of the design, modeling and simulation technology area at IACMI—The Composites Institute.

Those advances in aircraft modeling are reflected in the composites industry, where simulation programs for the design of composite materials and products have grown more complex, more comprehensive and more detailed. But there are still gaps in composites models that both industry and research organizations are working to overcome.

Evaluating Performance

Chintan Ved, senior engineer for materials development at Ford Motor Company, employs simulations to determine which parts in vehicles’ transmission and drive lines could be manufactured from composites to reduce weight. “We use all of the analytical tools which we have within our system and in the industry in general to convince us that [the composite] meets the performance criteria and at the same time extracts the benefits of new materials that have been developed by the industry,” says Ved.

Modeling composite parts helps Ford engineers understand the tradeoffs involved when they’re using the material in each application, part or duty cycle, he says.

Ford has adapted its proprietary simulation software, which it has used for years in working with metals, to model composites. But the automaker also works with resin manufacturers, who have developed their own mold flow analyses. “The resin manufacturers do a good job with that, so we combine that and feed it into our regular CAD and CAE models to make sure that between the brains at both houses we don’t miss anything,” says Ved.

composite-tool-purdue

Purdue researchers modeled this composite tool for a pin bracket before they 3-D printed it from polyphenylene sulfide (PPS) and carbon fiber. The finished pin bracket, which was molded from carbon fiber thermoset prepreg, is in the
foreground. Photo Credit: Purdue University