ALGOR DESIGN OPTIMIZATION PASSES TEST BY ROCKFORD POWERTRAIN

An Algor stress contour of the Rockford Powertrain end yoke is shown. The photo to the right shows the actual part that was purposely tested to destruction in the lab. Note that the high stress areas shown in the analysis closely match the actual breaking point.

Many companies find it difficult to meet their customers' requirements for high quality, low-cost components using traditional methods to test new materials and innovative designs. Creating and testing prototype parts is the traditional way designers investigate material and design options. However, this process can be so expensive, the costs may outweigh any potential savings.

Rockford Powertrain, Inc., a leading supplier of drivetrain components to heavy equipment manufacturers such as Caterpillar and John Deere, utilizes Algor design optimization and engineering analysis software to resolve these issues during the design process. This greatly reduces the need for prototypes and laboratory experimentation and makes it possible to test many more design options in a given amount of time.

Prior to making Algor software an integral part of their design process, Gordon Cummings, Rockford's Senior Product Engineer, decided to put Algor software to the test.

Rockford Powertrain Senior Product Engineer Gordon Cummings is seen here with the end yoke model on his computer screen.

The Test

"At Rockford, our most important consideration is providing value to our customers," says Mr. Cummings, "The most important part of value is performance. We are constantly searching for the most cost effective materials and designs possible without sacrificing performance. Traditionally, this required lengthy physical testing. For that reason, Rockford has an extensive library of parts that have been tested in the laboratory.

Modeling an Existing Part

"I knew that by using Algor software to model and analyze an existing component that had been destructively tested in the laboratory," continues Mr. Cummings, "A better understanding of the stress distribution could be obtained. A close correlation of the two methods would instill confidence in the use of Algor software to evaluate new designs."

One of the parts Mr. Cummings selected for testing was an end yoke, one component of a driveline assembly that is popular in mining, construction and agricultural equipment. In service, this component must withstand a variety of forces at constantly changing angles. The design is also limited by the amount of clearance required.

Algor Predicts Breaking Point

Mr. Cummings used Algor's Superdraw II to turn an imported AutoCAD file into a 3-D surface representation. He then used Hypergen to create a solid, tetrahedral mesh. To save time and disk space, Mr. Cummings decoded the solid mesh into 4-node tetrahedral elements for analysis. Although 10-node elements may also be used, it was not necessary in this case.

After applying the proper constraints, a torque load was applied to the top edge of the driving keyway. In Mr. Cummings' words: "The Algor analysis predicted the failure locations on the tested part with a high degree of accuracy. A comparison to the actual parts from our fatigue testing machine shows failures along the clusters of tetrahedrons with the highest stress levels in the Algor model."

Other Algor Applications

Since completing the successful testing of Algor software, Mr. Cummings has reduced the time and cost involved in designing a variety of new components. "By using Algor software," he says, "many materials and configurations can be evaluated in a short period of time. Physical testing is reserved for only the most promising designs. This not only saves time and money, it delivers a more reliable, cost-effective component to the customer.

"One example of the use of Algor software involved an application which required that forgings be replaced with stampings," continues Mr. Cummings, "Algor was used to determine the preferred shape of the part for maximum stiffness. Over twenty iterations were run without ever cutting metal. The final part performed as predicted."

About Algor

Don't ask Mr. Cummings what he likes about Algor unless you have some time. In his words: "My favorite part of Algor is Hypergen. I can take an AutoCAD drawing, pop it into 3-D in Superdraw II and mesh it in short order. With Hypergen, it's easy to generate a solid mesh in parts with lots of compound surface curves. Hypergen blasts through the model like butter. The capability to slice a part and examine the internal stresses is also advantageous.

Jetview Useful

"If I had to pick the single most useful Algor feature," says Mr. Cummings, "It is Jetview. I use it so much I forget about it. The capability to spin around a part to any position I want is one of the major strengths of the program.

"I don't know how many of Algor's users utilize the stereoscopic capability of Superview," continues Mr. Cummings, "but there are many models that would have been impossible for me to complete without this feature. The engineering department has finally stopped laughing when they see me in the red and blue glasses well, almost but the occasional visitor has a difficult time understanding the sight."

Algor's 3-D glasses may not qualify Gordon Cummings for Gentlemen's Quarterly, but his work with Algor software should get him an award for designing better, less costly products for Rockford Powertrain customers.

Algor 3-D glasses.

Copyright © 1993 Algor, Inc. All rights reserved.