How are damaging modes determined in gear resonance analysis?
Modes should be evaluated and characterized by their impact on amplifying gear tooth root bending stresses. If not addressed, damaging modes could magnify fatigue bending stresses and cause tooth bending failures of the gear. Once determined, damaging modes can be shifted or gear damping techniques applied to the design.
How are gear resonance tests used in helicopters?
In main power drive applications for helicopters as well as aircraft mounted accessory drives, gear resonance response tests, known as rap tests, are conducted to determine by test, the frequencies and shapes of gear resonance modes.
How is FEA used to determine gear resonance?
Once determined, damaging modes can be shifted or gear damping techniques applied to the design. Finite Element Analysis (FEA) is used to determine gear resonance frequencies, which are compared to the usage of the aerospace gear. Figure 1: Gear/gearshaft development for resonance.
What is the meaning of gear resonance excitation?
Gear resonance excitation is a phenomenon where natural frequencies of the gear and shaft are excited by operating speeds. Depending upon the mode shape of the natural frequency, tooth root bending stresses can be amplified beyond intended design limits.
What are the resonance modes of aerospace gears?
Natural resonance responses of the gear head and shaft change in frequency and amplitude as weight is reduced for aerospace gears. Care should be taken to understand the gear resonance modes and compare the modes with operating speeds.
In main power drive applications for helicopters as well as aircraft mounted accessory drives, gear resonance response tests, known as rap tests, are conducted to determine by test, the frequencies and shapes of gear resonance modes.
Once determined, damaging modes can be shifted or gear damping techniques applied to the design. Finite Element Analysis (FEA) is used to determine gear resonance frequencies, which are compared to the usage of the aerospace gear. Figure 1: Gear/gearshaft development for resonance.
Gear resonance excitation is a phenomenon where natural frequencies of the gear and shaft are excited by operating speeds. Depending upon the mode shape of the natural frequency, tooth root bending stresses can be amplified beyond intended design limits.