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Re: simulation, padaptive, aadaptive
Seckin Uslu Dec 28, 2014 4:34 PM (in response to 1 1)These are mathematical methods for convergence.
Summary
H adaptive about mesh.
Padaptive about energy.
With these method you will see how your works convergence.
However if you sure your works , you don't need to use these methods.

Re: simulation, padaptive, aadaptive
Mike Pogue Dec 29, 2014 11:43 AM (in response to 1 1) H adaptive means to solve the problem at one element size, then solve again at a smaller element size and compare the solutions.
 P adaptive means to solve at one element order (linear, quadratic, cubic, quartic ...) then the next and compare the solutions
 A loop is solution.
 The program will refine the mesh in areas of high stress gradient in order to converge. Converge means to find a solution that does not change with respect to mesh size/order.
 RMS is root mean squared. It is a measure of the average change in element stress, but corrects the problem that if some go down and some go up, the average could be zero, even though there were big changes. You calculate it by subtracting the stress in each region on this loop from the stress in the same region on the last loop and squaring it. Now do the same for all the regions. Now add them up. Now take the square root. It is identical to the standard deviation assuming the mean is zero.
 Strain energy is the volume integral of Hooke's law. It's how much energy is stored in your system from the internal spring forces resisting your loads. As a convergence parameter, it has the advantage that it will converge even though there may be singularities in your model, as infinite stresses become concentrated in infinitesimal elements.
 Target accuracy is how much change in these parameters you are willing to tolerate between loops before calling it good enough. If you run enough loops at high enough order or small enough elements, the change should approach zero in theory. This is the single most important fundamental fact underlying Finite Element Analysis.
 Accuracy bias, if I remember correctly, is whether you'd rather cheat towards accuracy in local, high stress gradient regions, or total (global) accuracy. As the program refines the mesh.

Re: simulation, padaptive, aadaptive
1 1 Dec 31, 2014 6:45 PM (in response to Mike Pogue)Thank you very much. Excellent help.

Re: simulation, padaptive, aadaptive
Jared Conway Jan 2, 2015 12:38 PM (in response to 1 1)mike's got everything covered here
padaptive, and hadaptive are both great tools for finalizing a solution if you don't want to go through the manual convergence proces
