Designing Enging Isolators
Paul Fuhrman of the Lord Corporation (founded by Hugh Lord in 1924) gave us a simplified explanation of what is involved in designing a device that will effectively vibrationally isolate the airframe and engine of an airplane. Step one is ground vibration testing of the airframe to find its natural vibrational frequency. Every object has a natural resonant frequency-think of a tuning fork. All engine isolation systems are designed to prevent the suspended mass-the engine and propeller-from exciting the resonant frequency of the airframe. Doing so will cause everything from discomfort to the occupants through damage to the airframe and components.