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elastic wave propagation

Posted Aug 8, 2017, 9:58 p.m. EDT Structural Mechanics Version 5.3 2 Replies

Mohammad Mohammadi
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I am trying to simulate wave propagation in an elastic half space medium due to a vertical load.
I have defined a 100Hz sin pulse with one period duration as the vertical force.
And I like to observe displacement at several points.
But the result is not as I suppose to see. the displacement vs time plots are jagged and I cannot see the passing wave. I have changed mesh quality and time steps but it does not work.
Please help.

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2 Replies Last Post Aug 9, 2017, 10:45 a.m. EDT
Dave Greve
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Posted: 7 years ago Aug 8, 2017, 10:26 p.m. EDT
Updated: 7 years ago Aug 8, 2017, 10:31 p.m. EDT
1. Your mesh is very odd, you need several elements per wavelength but not an extremely large density near the edges.

2. The most common reason wave propagation doesn't work is allowing the solver to take free steps. Go to Study>Solver configurations>Solution>Time Dependent Solver and choose Strict for Steps Taken by Solver. Again, you need several steps per period but not hundreds or thousands.

D.W. Greve
DWGreve Consulting
1. Your mesh is very odd, you need several elements per wavelength but not an extremely large density near the edges. 2. The most common reason wave propagation doesn't work is allowing the solver to take free steps. Go to Study>Solver configurations>Solution>Time Dependent Solver and choose Strict for Steps Taken by Solver. Again, you need several steps per period but not hundreds or thousands. D.W. Greve DWGreve Consulting
Mohammad Mohammadi
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Posted: 7 years ago Aug 9, 2017, 10:45 a.m. EDT
Thanks for your consideration.
I have changed free to strict and the result is completely different.
Do you know where I can learn more about this option?
Thanks for your consideration. I have changed free to strict and the result is completely different. Do you know where I can learn more about this option?

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