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How do I input different load conditions for different time step for time dependent simulation
Posted 2012年2月13日 GMT-5 17:23 MEMS & Nanotechnology, MEMS & Piezoelectric Devices, Structural Mechanics Version 4.2 4 Replies
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I am trying to run a time dependent simulation for a piezo-electric beam. I will like to add a force at 0s and another at 0.5s on the edge of the beam. The simulation should run for 1s to determine the transient behavior for the whole duration of 0 to 1s. I am not sure how to specify the individual forces at the 2 times there seem to be no option for the timing under (rigid boundary->applied force) or other boundary loads. Also, how do I combine all these different load when setting the study options. Thank you very much.
Lionel
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what if you define a time series function with the laod value, and call it with an argument of "t"
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Good luck
Ivar
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Hi
what if you define a time series function with the laod value, and call it with an argument of "t"
--
Good luck
Ivar
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Hi Ivar,
So does that mean there is no other more direct way to define time dependent loads? Thanks.
Rgds,
Lionel
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I find it very direct to write out an equation or call a function in the field for the boundary load:
if you write (with a transient solver defined) totla BC force = 4[N]*(t<5)+10[N]*(t>=5)*(t<10) ...
you will get steps but such a function is discontinuous, and the solver will have problems tackling the steps.
It is then better to use a predefined "step()" function(s) as these have a smooth rise time (you may change its value) and then call BC force = 4[N]*step(t[1/s]) + (10-4)*1[N]*step(t[1/s]-5) ..
or even define an analytical function "ana1()" by calling the step functions as above, as then you can easily plot the function to check the shape
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Good luck
Ivar
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I want to give a input load which is varying slowly from to 0 to 1000 in 4 seconds ( linearly) , any suggestion how can i do that ?
Am very new here, sorry :(