Muhammad Haroon, a Purdue mechanical-engineering doctoral student, works on sensors installed in a car-suspension system at the university's Ray W. Herrick Laboratories.

Muhammad Haroon, a Purdue mechanical-engineering doctoral student, works on sensors installed in a car-suspension system at the university's Ray W. Herrick Laboratories.


The researchers claim their method shows precisely how damage changes a part's performance and how that change affects other parts in the suspension.

"Different component suppliers design their parts to be as rugged as possible," says Douglas E. Adams, an associate professor of mechanical engineering, who leads the research. "The problem with this approach is that some parts are overengineered and heavier than they need to be, resulting in systems that didn't handle very well, and higher fuel and steel consumption."

Now, automakers can test the entire suspension by analyzing parts as interconnected components. This integrated approach is important because a damaged part can cause strain on other parts. If engineers know which parts are prone to damage, they can make them heavier while making other parts lighter.

The method developed at Purdue senses naturally occurring vibration patterns to detect damage. Triaxial accelerometers collect data as vibration passes through the suspension components. Software programs then interpret the information to analyze each part's performance.

Such "fault-identification" methods not only provide information for designing better suspensions but could also be used for future structural-healthmonitoring systems that automatically detect damaged parts. Researchers hope to develop the method in less than two years.

ArvinMeritor Inc., which makes suspension components at its Columbus, Ind., plant, funds the research.