Hi,

I would like to analyze the structure of the UAV that I have for different loading conditions. It is a simple quad-copter with co-axial motors at each motor arm (I have 2 motors at each arm, so 8 motors in total). I have a global FEA model where I have all of the structure meshed with proper properties assigned to the elements and also ensuring element quality and connectivity. I have difficulties in choosing the right boundary conditions.

I ran a few test cases to understand the behaviour of the FEA model (basically, checking the reaction loads at constraint points). Among these test cases, the boundary condition which fit right was where I constrained the 3 translational degrees of freedom at the motor-points and applied mass elements for the motor, payload (5 kg), and the battery and ran 'gravity load analysis'. The reaction forces at the constraint points were equal to the thrust I would require to hover.

Now, I would like to understand how will the structure behave for the one-motor-failed condition. What boundary condition can I go for this case? Say, if what I have so far is incorrect and I need to assign loads at the motor points, where do I constrain my model?

Any help is highly appreciated. Thanks in advance!

Regards,

Shahid

Seems like a cool study! What FEA solver are you using for this? I would just assume that the easiest way to do what you are asking would be to apply your thrust load to each mass nodes where each motor is and then remove the load from the failed motor? I know that's overly-simplistic but that's all I got with the information here. Different solvers will have different techniques of accomplishing this.