Lehigh University
Lehigh University


Lehigh students lighten the load for GM truck drivers

Josh Colistra '03 (second from left), shown with, left to right, Hulas King of UGS PLM Solutions, Elaine Chapman-Moore of Partners for the Advancement of
Collaborative Engineering Education, and Fred Wehden, senior computer consultant at Lehigh.

The medium-duty commercial trucks manufactured by General Motors, including the Chevy Kodiak, are rugged and versatile, able to haul stones or deliver beverages and still carry a crew of up to six passengers.

The trucks may one day add a new and unique utilitarian feature, thanks to prize-winning computational work done by Lehigh engineering students over the past two years.

The students, working first in Lehigh’s Integrated Product Development program and then on their own, have designed an access panel door that would enable drivers to check fluid levels without having to heft open the trucks’ 76-pound hoods.

One of the students, Joshua Colistra, now pursuing an M.S. in mechanical engineering at Lehigh, last month received first prize in a national student design competition sponsored by PLM (Product Lifecycle Management) World, an organization of companies that promote problem-solving with software.

Colistra, who earned a B.S. in mechanical engineering in 2003, traveled to the PLM World 2004 conference in Anaheim, California, last month to accept a monetary award and present the results of his team’s work.

The PLM competition emphasizes computer-aided design, computer-automated manufacturing and computer-automated engineering and requires students to solve a mechanical problem.

Colistra first tackled his problem – designing an access panel for GM’s trucks – in Lehigh’s IPD program, a yearlong class in which teams of engineering, business and arts students design and make products and develop marketing plans for industrial sponsors. He has continued working on the project since enrolling as a graduate student at Lehigh.

Colistra and his team members, ME majors Jose Ibanez ’03, Philip Fresconi ‘03 and Matt Shiels ’03, began their IPD project by visiting truck dealerships to inspect the hoods and engines of GM’s medium-duty trucks. They interviewed truck drivers and asked what kind of access panel they wanted for their trucks. They contacted GM’s suppliers to order necessary parts, and they analyzed three truck hoods shipped by GM to Lehigh.

GM required the students to satisfy 23 “constraints.” The biggest challenge was to design the access panel in such a way that, once installed, it would not reduce the stiffness of the hood and compromise its structural integrity.

“The new hood design must have stiffness greater than or equal to the original stiffness,” the team wrote in a report submitted to the PLM World Student Competition.

To achieve its objective, the team used finite element analysis to quantify the stiffness of the hood before and after the access panel was installed.

Finite element analysis is a computer model that can be stressed and analyzed in order to verify either the performance of new products being designed or improvements being proposed for existing products. Two types of finite element analysis are used in industry – 2-D and 3-D. Both allow programmers to insert multiple algorithms, or functions, which make a system behave both in a linear and nonlinear fashion. The Lehigh students used a 2-D model with “shell elements.”

To design the access panel, the students taught themselves to use Unigraphics NX2 Modeling, a software program employed by GM for modeling and design. The students then validated their design with finite element analysis.

For their final design, the students chose a prototype access panel door measuring 2.5 feet wide and 1.5 feet high that is bonded by a substructure to the inside of the hood to increase stiffness and rigidity. The door enables drivers to check levels of engine oil, brake fluid, engine coolant, power steering and transmission fluid. A Fluid Check Extension Kit designed by the students facilitates the process.

The new design, the students wrote in their report to PLM, “will actually increase the stiffness of the hood when compared to its original design.”

The students also validated their design physically, using a water-jet cutter to cut out the proposed access panel door from the truck hoods, then using stereolithography, a computer-directed, ultraviolet laser technique, to produce a plastic prototype, layer by layer. This portion of their project satisfied one goal of the PLM contest, which is to learn to reduce the time required to manufacture a product once it has been designed.

In March, the students and their IPD project adviser, Terry Delph, professor of mechanical engineering and mechanics, flew to Pontiac, Michigan, to present the results of their work to GM’s chief engineers and to show them a prototype of their access panel door installed on a truck.

The students turned over to GM the results of their finite element analysis, the method for doing the finite element analysis, the manufacturing process and the prototype.

In the conclusion to their report, the students reflected on the value of their IPD project.

“There have been many highs and lows throughout this IPD experience,” they wrote. “We have taught ourselves how to use a previously unfamiliar software package (Unigraphics NX2). We have also learned how to deal efficiently with subcontractors and other people in the automotive industry.

“In particular, the finite element analysis [we] conducted pushed the boundaries of what we are able to accomplish, and was quite likely the most numerically intensive piece of work ever conducted at the undergraduate level at Lehigh.

“As a group, we have [gained] more real-world experience in this class than any other.”

--Kurt Pfitzer

Posted on Thursday, June 10, 2004

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