There may be a sign convention inconsistently in the new draw() method. Please submit and issue on github about this.
Thanks, Jason moorepants.info +01 530-601-9791 On Sun, Mar 1, 2020 at 8:48 AM Alejandro Martín Hernán < [email protected]> wrote: > Hi Jashan, > > Thank you for your answer, but then the b.draw() method uses a different > sign criteria since in the sketch provided above if the moment is negative > means counterclockwise which is the desired sense and if we introduce the > moment positive the plot shows the moment in the clockwise direction as it > is shown here: > > [image: Figure_1.png] > > > El domingo, 1 de marzo de 2020, 17:27:46 (UTC+1), Jashan escribió: >> >> Hello Alejandro, >> >> The issue is with the sign convention you used for the moment at x=2m. >> Changing its sign will give you the correct answer: >> >> *>>> b.apply_load(1250, 2, -2)* >> *>>> b.apply_load(4000, 4.3, -1)* >> *>>> b.apply_load(3000, 6.3, 0, 8.3)* >> *>>> b.solve_for_reaction_loads(R_0, R_8)* >> *>>> b.reaction_loads* >> *{R₀: -2801.20481927711, R_8.30000000000000: -7198.7951807229}* >> >> >> >> On Sunday, March 1, 2020 at 8:35:24 PM UTC+5:30, Alejandro Martín Hernán >> wrote: >>> >>> Hi everyone! >>> >>> I has been testing the continuum mechanics module in order to understand >>> how it works for the gsoc2020, but I found a problem. >>> I was trying to calculate the reaction forces of the following beam to >>> validate the module, knowing that the reactions are R_0 = -2801.2 N and >>> R_8.3 = -7198.8 N. >>> >>> [image: Screenshot from 2020-03-01 14-16-39.png] >>> However, the results obtained are: {R_0: -2500.00000000000, >>> R_8.30000000000000: -7500.00000000000}. This is not correct since if we >>> calculate the equilibrium of moments about a point it is not zero because >>> the beam must be in equilibrium. The code used was: >>> >>> >>>from __future__ import print_function, division >>> >>>from sympy import * >>> >>>from sympy.external import import_module >>> >>>numpy = import_module('numpy', import_kwargs={'fromlist':['arange']}) >>> >>>from sympy.physics.continuum_mechanics.beam import Beam >>> >>>from sympy import symbols, Piecewise >>> >>>init_printing(use_unicode=True, wrap_line=False) >>> >>>E, I = symbols('E, I') >>> >>>R_0, R_8 = symbols('R_0, R_8.30000000000000') >>> >>>b = Beam(8.3, E, I) >>> >>>b.apply_support(0,'pin') >>> >>>b.apply_support(8.3, 'roller') >>> >>>b.apply_load(-1250, 2, -2) >>> >>>b.apply_load(4000, 4.3, -1) >>> >>>b.apply_load(3000, 6.3, 0, 8.3) >>> >>>b.solve_for_reaction_loads(R_0, R_8) >>> >>>b.reaction_loads >>> >>>b.draw().show() >>> >>> [image: Figure_1.png] >>> The sketch looks well. I do not know if I am making someting wrong, but >>> I will try to solve the problem. >>> >>> >>> -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/6f661e46-10f0-4bbe-a43e-b6b4c43aba78%40googlegroups.com > <https://groups.google.com/d/msgid/sympy/6f661e46-10f0-4bbe-a43e-b6b4c43aba78%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAP7f1AgdH_tLo6d0a-AkwSkRx1zkAob0S%3DUqJcg%2Bsrsdz69asA%40mail.gmail.com.
