Regarding ABAQUS ?

[Susmita Ghimire]

How can we increase the number of cycles in periodic amplitude in ABAQUS as it is giving only 3cycle for every frequency range. I want to plot up to 3 sec for every frequency starting from 2pi to 20pi .

 

[FEA way]

Periodic amplitude definitions are quite complicated, there are several inputs that you can adjust. Abaqus has a feature to plot the amplitude once it's created. However, it might be more convenient to be able to plot it right after making modifications, without having to switch to the Amplitude Plotter plug-in. For this purpose, you could write a code to plot the piecewise function (involving Fourier series) that defines the periodic amplitude (you can find the formula in Abaqus documentation). Then just change the inputs and recompile. If you want, I can share such a code written for wxMaxima (open-source counterpart of Mathematica).

 

[Susmita Ghimire]

Thank you very much for your response but I am not able to open ABAQUS documentation to search these codes. You mean I should write the codes in input file of ABAQUS by myself?

 

[FEA way]

No, it's not necessary. What I suggested is just a convenient way of preparing inputs for the periodic amplitude so that it matches your expectations. However, it would be good if you had access to Abaqus documentation (you just need Dassault Systemes account for that) since the formulas provided there explain the theory behind this type of amplitude and will let you understand how it works.

 

[Susmita Ghimire]

Thank you very much. As you said you can share the code written for wxMaxima, can I please see it. I was also thinking to create a table in excel and then import in the form of tabular data.

 

[FEA way]

Sure, here's the code for wxMaxima:

a_1(t):=A[0]+sum(A[n]*cos(n*ω*(t-t_0))+B[n]*sin(n*ω*(t-t_0)), n, 1, N);
a_2(t):=A[0];
a(t):=if t>=t_0 then a_1(t) else a_2(t);
N:2$
ω:31.416$
t_0:-0.1614$
A[0]:0$
A[1]:0.227$
B[1]:0$
A[2]:0.413$
B[2]:0$
wxplot2d([a(t)], [t,0,0.5], [ylabel,"a"])$

It uses inputs from the example in Abaqus documentation but of course you can replace them with your own inputs.

 

[Susmita Ghimire]

Thank you very much