Do your Designs Sing?

We often consider design to be safe if prototypes work out fine, or if over a period of time legacy data has paved the way. If comfortable with analysis, static tests are the first line of defense to prove concepts. Knowing loading conditions, and component interaction with its environment we identify success with an appeasing color chart of blue and green colors. Could it be we missed a few nuances making our best design not perform as planned? Let me clarify….

As you're cruising along in your ride there is a sudden noise that always occurs at a certain speed. It goes away as soon as you cross that speed. Or remember the time when the plastic stool could not hold your weight and you simply attributed that to Walmart’s poor quality products. How about excessive use of certain microwavable utensils and then suddenly the lid never fits. Do you think these all are poor designs or someone didn’t do their homework? Can there be a similar case at work…..how about the motor in a plant shop that hums at a certain rpm, or certain portions of work space that are over cooled compared to others. Maybe it's time we tried to look at designs in their environment, rather than simply understanding loading conditions.

 

Frequency / Modal tests: The reason why you hear odd sounds in the car is because a car body’s natural frequency matched the rate at which wind load was acting on it, the same reason why the motor in plant shop hums at a certain rate. This concept is called resonance. In the case of a guitar, resonance appeases ear buds.

 

Buckling tests: WalMart’s plastic stool which is designed to hold a certain weight failed because of a phenomenon called buckling. When thin slender cross sections are subjected to compressive loads they fail in a combination of yielding and buckling. The material cross section deforms slightly and hence incapacitates it from providing resistance to an applied load.
   

Thermal tests: When a component heats up it expands. This is precisely the reason why there are gaps in rail road tracks. There are slots made in the cutting blade of a saw to accomplish effective heat dissipation.

Fatigue tests: When a component is repeatedly loaded and unloaded, there are residual loads left in the component. This is what causes the microwave utensil lids to not fit in after an extended period of usage.

COSMOS or SolidWorks Simulation can help you account for all possible design scenarios. The idea is to empower you to think more about your designs rather than the design process.

Rajat Trehan

Product Manager - Design Validation

Computer Aided Technology Inc.