ALGOR AND CADKEY 97 GIVE WEBB WHEEL A COMPETITIVE ADVANTAGE

Algor's von Mises stress contour shows Mr. Kelley where high stresses (red) will occur. Low stress areas (purple) are studied for weight reduction.

September 4, 1998, Pittsburgh, Pennsylvania - Heavy truck and tractor trailer manufacturers including Volvo, Navistar, Freightliner and Peterbuilt look to Webb Wheel Products, Inc., of Cullman, Alabama, to provide wheel-end components that are optimized for strength vs. weight and delivered in a timely manner. Webb Wheel meets those demands by reducing unnecessary prototype testing and optimizing its designs of wheel-end components such as spoke wheels, hubs and brake drums using CADKEY 97 and the mechanical engineering software of Algor, Inc., based in Pittsburgh, Pennsylvania.

"Producing prototypes is an extensive process which typically takes four to eight weeks," explained Ken Kelley, Chief Engineer at Webb Wheel. "Ninety-nine percent of the time we can produce a prototype that passes testing the very first time using CADKEY 97 for design and Algor software for finite element analysis. The efficiency of our design cycle gives us a competitive advantage in the heavy truck and tractor trailer industry."

Recently, Mr. Kelley and Paul Levering, Webb Wheel's Vice President of Engineering, used CADKEY and Algor to design a new hub which connects the tire rim to the axle. The new design was necessary to accommodate a new industry-standard axle.

Mr. Kelley created a two-dimensional wire frame of the hub in CADKEY 97. He then imported the wire frame into Algor software as an IGES file and extruded it into three dimensions. Industry-standard specifications called for the design to be tested under 13,000 lb. of force. Applied boundary conditions fixed the hub around the flange. Mr. Kelley analyzed the "brick" finite element model of the ductile iron hub using Algor's linear static stress analysis processor.

"Our two major concerns are fatigue strength and the strength to weight ratio of the hub," said Mr. Kelley. "Algor's von Mises stress contour showed me where high stresses were going to occur. Low stress areas were studied for weight reduction."

"I also looked at Algor's precision contour display to determine where the model required a tighter mesh to provide more accurate analysis results," added Mr. Kelley.

Armed with these analysis results, Mr. Kelley optimized the design to reduce areas of high stresses and reduce material in low-stress areas. He also optimized the mesh in the areas highlighted in the precision contour.

Mr. Kelley created and analyzed several models before a final design was reached. Webb Wheel then produced a prototype hub for laboratory testing on a rotary fatigue test stand. The rotary fatigue test stand simulates higher stresses than the hub would ever experience on the road. Like nearly all of Webb Wheel's designs, the hub withstood the test.

"Recently, we designed a component for a client who required strain gauges to be used on the prototype," said Mr. Kelley. "Strain gauge readings correlated very closely with the Algor analysis results."

Mr. Kelley is currently working on adding FastSOLID and FastSURF for three-dimensional modeling and Algor's automatic meshing technologies for finite element mesh generation and refinement. These tools will enable Mr. Kelley to create models that more closely represent the fillets, blends and holes of Webb Wheel's wheel-end components.