Impact Setup

[austen.williamson]

I have been trying to figure out how to run the drop test analysis for some time now and have watched several tutorials but they do not show how to make the impact surface. They all start with the surface created like in the picture. I assume you don't create and actual sketch and extrude it but don't understand how it's supposed to be made. 

[shigeaki.k]

Hello @austen.williamson,

the model shown in the screenshot shows the shell surface. You can either,

• make a thin 3D part in the CAD software package, use the mid-shell capability in Nastran In-CAD, and then apply the shell idealization to the mid-surface (see figure below).
• make a surface part in the CAD software package and apply the shell idealization to the imported surface in Nastran In-CAD.
• Use the offset function on a surface of a 3D part in Nastran In-CAD (see figure below).

You may already know but just in case you don't, the "Drop Test your Design in Autodesk Nastran In-CAD" in the Autodesk Simulation Youtube Channel may also be of interest to you. 

Regards,

Shigeaki K.

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[John_Holtz]

Hi @austen.williamson

To expand on Shigeaki's reply, you DO create a part or assembly for the thing that is being impacted. If you are impacting a ball into a car, you create a model of the car. If you are impacting a bracket onto the floor (like in the video), you create a model of the floor.

In the case of the video and what Shigeaki's reply was related to, the floor can be modeled as a solid (a part that has thickness) or as a surface (a part that has not thickness, and the analysis uses shell elements which are assigned a thickness). The video used a surface, so a sketch was created, and then the Patch command was used to create a surface from the sketch.

All of this modeling is done in the modeling environment before entering into the In-CAD environment.

Hope this helps.

[shigeaki.k]

Hello @austen.williamson,

let us know if we were able answer your question. If so, could you hit the "accept as solution" button to John or my posting? This will allow others to find solutions to questions on the forum.

Regards,

Shigeaki K.