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Help with modeling hammer impact to simulate pyro-shock

Re: Help with modeling hammer impact to simulate pyro-shock

Thank you Denis for the pdf. Given a proper modal anaylsis caputuring all the modal responses it seems I can get valid results with simulate.

I exported the results of the normal reaction force on my 3D contact surface to excel. I deleted the data to include only the data where their was a non-zero impact force. I then numbered each data set with 0.001 increments (as 0.001 is the time incriment I used in the mechanism analysis) I then saved this and imported the results for the time dependance in a dynamic time analysis in simulate. However I get an error measure trying to click of, it says no measures valid for the dynamic analysis have been defined for your model.

I have a load with a magnitude -1 in the Z direction since I figured it will multiply by the imported time dependent loading I have in the dynamic time analysis.

Re: Help with modeling hammer impact to simulate pyro-shock

Ok so I see that I did not have my measure defined in simulate. So I defined a measure to measure the acceleration of my impact plate, but when trying to run the dynamic time analysis it still is giving me a fatal error.

Ok so I suppressed the hammer swing mechanism so the model would just contain the frame and the dynamic analysis ran. I graphed the measure of the acceleration response of the impact plate fixture and the results look somewhat valid at a peak of 31g's. Now im guessing as was said earlier that im getting some modal truncation since my peak response was only a small 31 g's and that I need to capture some higher modes since my modal analysis was only done with 6 modes.

Im going to try as Shaun suggested and look at the frequency analysis and the displacement to make sure I have enough modes, but I might try to just run another modal analysis to caputure all the modes in the 3000-10000Hz range which is the range of mid field pyroshock.

Im still confused on how to define the loads for dynamic time analysis. Right now I just have a base load applyed over a very small impact region with the magnitude of 1 I defined on the impact plate from looking at the contact region in mechanism. I also have the load I imported from excel for the impact load over time. I assume since the magnitude of the load is one it will just multiply that by the imported load from the table?