Radicaldude1234
Well-Known Member
After a bout of procrastination, I'm currently transitioning my design from aerodynamics to designing the actual structures. To that end, I'm trying to come up with a comprehensive list of loads to design to. Coming to wing loads, I realized that I perhaps have a gap of knowledge as to what forces, and therefore structural loading, limits the top speed of the aircraft.
Just wanted to see from my brief research if I was on the right path? The wing loads would presumably apply equally to tail surfaces.
Static Loading Parameters:
Vertical Wing Loading: Maybe? The vertical component of at maximum load factor should be the same at Va or Vne/Vd.
Drag Loads: Induced drag should be more or less the same since the necessary Coefficient of Lift decreases with higher speed, but the parasitic drag would rise with velocity. Max speed would be where the aerodynamic forces tear the wings off towards the rear of the aircraft.
Torsional divergence: The aerodynamic moment of the wing overcomes the structure and twists it off the aircraft.
Aileron Reversal: The increase moment of applying ailerons twists the wing so that the opposite control input is observed.
Dynamic Loading Parameters:
Flutter: The speed at which the structural damping goes to zero (undamped), or negative (increasing oscillation)
Methodology:
For Static Parameters: Find the equations and solve for required value.
For Dynamic stuff:
1. Solve for torsional stiffness required at flutter speed (at safe margin above Vne)
2. Develop simplified mathematic model of wing and verify.
3. Create FEA model to verify.
So am I on the right track? Are there forces that I've missed?
Thanks in advance!
Just wanted to see from my brief research if I was on the right path? The wing loads would presumably apply equally to tail surfaces.
Static Loading Parameters:
Vertical Wing Loading: Maybe? The vertical component of at maximum load factor should be the same at Va or Vne/Vd.
Drag Loads: Induced drag should be more or less the same since the necessary Coefficient of Lift decreases with higher speed, but the parasitic drag would rise with velocity. Max speed would be where the aerodynamic forces tear the wings off towards the rear of the aircraft.
Torsional divergence: The aerodynamic moment of the wing overcomes the structure and twists it off the aircraft.
Aileron Reversal: The increase moment of applying ailerons twists the wing so that the opposite control input is observed.
Dynamic Loading Parameters:
Flutter: The speed at which the structural damping goes to zero (undamped), or negative (increasing oscillation)
Methodology:
For Static Parameters: Find the equations and solve for required value.
For Dynamic stuff:
1. Solve for torsional stiffness required at flutter speed (at safe margin above Vne)
2. Develop simplified mathematic model of wing and verify.
3. Create FEA model to verify.
So am I on the right track? Are there forces that I've missed?
Thanks in advance!
