Projectile Collision

mogmog
I'm attempting to model how a panel deforms over time due to the impact of a projectile, this is a simple version of what I'll eventually be modelling but I figured I'd start off with an less complex model. To be more specific I'm trying to simulate a bulletproof shield. The final model will use a much smaller projectile and a panel made up of many thin layers, (not too sure how this would impact the elements I should use, potentially by layering shell elements? For now I've just used Automesh 3D on a thin-ish cuboid). The goal is to model the point of failure and then simulate again using lower energy impacts.

Values for material properties and forces will be changed, just stuck some numbers in for now whilst I'm trying to get things started.

I've been fiddling round with it and going through tutorials from the manual but I can't seem to get the two objects to interact. I've used ABAQUS in uni before and have a basic understanding of FEA software but I'm a bit rusty so it might just be a simple solution that I'm overlooking.

I'm also using the free version, so I only have 1000 nodes to play around with right now, however if I can get something working then I'll definitely be wanting to upgrade so I can properly refine the mesh and get some better results. Just gotta convince my boss that it will be a worthwhile purchase.

Any pointers in the right direction would be much appreciated :)

Comments

  • kennethfugatekennethfugate
    Search for "Explicit Analysis" or "Bouncing Sphere" in the forum for some impact examples.
  • VictorVictor
    Contact stiffness is so low that it looks like they aren't interacting. Units are Pa/m but should probably be GPa/m.

    You can set the entire surface of the plate as contact face instead of a patch in the middle.
  • JohnMJohnM
    I think I've posted this before, but couldn't find it, so here it is (again I think):

    Think small - small models, small time steps. Model sizes can grow after things start making sense.

    Very stiff models are hard to run/converge. Run a modal analysis on your system to determine the time step requirements. For example, if your first mode is 1000Hz, you probably want a time step of 1/(10x1000).
    The first mode in your test model is about 4000Hz, pretty "stiff", and requires very small time steps to characterize anything but the very first responses.

    Use gravity.

    Use an initial velocity through custom model definition, this can be the impact velocity and the model can be moved a small distance from impact.

    Lately the PASTIX solver works great, but if there is an issue always check by using PARDISO.

    Learn how to use Ralyeigh Damping


    Attached is a drop test test model that should give you some guidance.

    Video of drop test:

    https://drive.google.com/file/d/1YoOZL2CkIpOp4VWZYrkHO1ogdi1oV8IQ/view?usp=sharing
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