Understanding the results of a dynamic simulation

Project Support
1

Hello everyone, in this simulation I’m trying to see how solicited is the undercarriage of our model aircraft when landing with a vertical speed of 4 m/s. The impact happens at 0.002-0.003 s, but the biggest von Misses stress supported by the landing gear is at 0.004 s. On the following iterations, the von Misses stress increases, but affecting other parts of the aircraft.
Now, I find it difficult to interpret this results. Are the results still reliable 3-4 iterations after the impact? Where should I read the main stress of the landing gear? Should I be worried of how the other pieces of the aircraft are solicited or should I only focus on the main piece I wanted to simulate (the undercarriage)? I’m relatively new to SimScale so I’d appreciate a little guidance.
Link to the project: https://www.simscale.com/workbench/?pid=5666843395578550340&mi=spec%3Ada993482-498b-4401-8eb5-fd4117a0653e%2Cservice%3ASIMULATION%2Cstrategy%3A10

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Hi Dani!

I had a look at your simulation, and I have to say congratulations because you are on the correct path.

Still, there are a few aspects to improve in order to have better results. Please review these:

  1. To reduce the penetration between the wheels and the floor, you should increase the contact stiffness in the physical contact definition. Currently you have ‘low’, please try with ‘medium’ or ‘high’.

  2. If you want to have reliable stress results, you need to improve your mesh. By having a look at your geometry, I think you will benefit a lot from an structured mesh, created using sweep meshing and thin wall refinements. Also, region refinements must be added in areas such as the wheel shafts to properly capture the curvatures.

  3. Your time step is currently a little high to properly capture the stress history, and also you could extend the end time to capture all the impact event.

3

Thank you for the advice, I refined the mesh of the wheels and undercarriage and the results were pretty different. I also set the contact stiffness at high and halved the time step. All in all, it was very helpful and I am very grateful for your help!
Thank you again and Happy Easter if you are celebrating tomorrow!

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