No it doesen't work.
hm:http://www.file-upload.net/download-8536879/Fl--gel.hm.html
nas:http://www.file-upload.net/download-8536890/Fl--gel.nas.html
I meshed it witch this settings. (Sorry it's the first time i use HyperMesh)
http://www.pic-upload.de/view-22012014/mesh.png.html
Can you upload your hm and nas file? Then i can try yours. Maybe its a software problem.
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Re: Report problem VWT
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Re: executive files are empty when installing Hw 12
thank you.
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Re: facing error regarding element quality
Warpage of up to five degrees is generally acceptable.
where have you attached the file? see http://www.altairuniversity.com/support-forum/?mingleforumaction=viewtopic&t=124
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Re: facing error regarding element quality
sorry sir i am attaching the file now
![Image]()
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Re: facing error regarding element quality
sagarsrm,
- I suggest you repair these elements, and also remesh perhaps using trias only in the problem regions,
you can change the warpage check value to 15% and focus only on high warpage elements, unfortunately you have elements with 95% warpage, these have to be corrected.
You could actually do some mesh editing in certain regions with high warpage,
Go through 8.2 General Element Quality Checks in the student guide, you can use the table there to judge for yourself.
See http://altair-2.wistia.com/medias/odgq77jx0a to learn about general mesh quality and editing
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Re: facing error regarding element quality
thanks sir i will try to remove warpages with very high value
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Odd SPC force output at topologie optimization analysis
Hi,
I wanted to check the SPC forces in my model and found something strange. In different iterations with nearly the same mass and the same load case (GRAV card) there were different SPC forces.
My load case looks like: (20g in X and Y / 25g in Z; Unit: mm/s^2)
$HMNAME LOADCOL 3"LC_+X+Y+Z"$HWCOLOR LOADCOL 3 5$$ GRAV 3 01.0 196200.0196200.0245250.0The *.out file (just a part) looks like:
Design Parameters Summary :
---------------------------
Total # of topology design elements : 258636
Total # of topology cards : 1
Total Volume of Design Material : 3.8620E+06
Total Mass of Design Material : 1.1586E-02
Volume of Non-Design Material : 1.5629E+04
Mass of Non-Design Material : 8.2989E-04
ITERATION 0
Residual energy ratio for static load case 2 = -4.201099E-09
--------------------------------------------------------------------------
Label x-force y-force z-force x-moment y-moment z-moment
--------------------------------------------------------------------------
Sum-App. 4.264E+02 4.264E+02 5.330E+02 -2.312E+05 9.687E+04 1.075E+05
Sum-SPCF -4.264E+02 -4.264E+02 -5.330E+02 2.312E+05 -9.687E+04 -1.075E+05
--------------------------------------------------------------------------
Objective Function (Minimize WCOMP) = 5.03774E+03
Maximum Constraint Violation % = 0.31156E+02
Design Volume Fraction = 3.57023E-01 Mass = 4.96639E-03
ITERATION 1
Residual energy ratio for static load case 2 = -2.439880E-09
--------------------------------------------------------------------------
Label x-force y-force z-force x-moment y-moment z-moment
--------------------------------------------------------------------------
Sum-App. 5.995E+02 5.995E+02 7.494E+02 -2.361E+05 9.898E+04 1.097E+05
Sum-SPCF -5.995E+02 -5.995E+02 -7.494E+02 2.361E+05 -9.898E+04 -1.097E+05
--------------------------------------------------------------------------
Objective Function (Minimize WCOMP) = 4.29319E+03 % change = -14.78
Maximum Constraint Violation % = 0.41841E+02
Design Volume Fraction = 3.57024E-01 Mass = 4.96640E-03
And if i calculate the SPC force for iteration 1 (F=m*a) i get 974 N instead of 599.5 N.
Can anybody explain this?
Thanks
Linus
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how to create vector graphics in hyperview
Hi,
is there a possibility to export screenshots of e.g. stress contour plots of my FEA results as vector graphics such as .eps files?
Best regards
David
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Re: how to create vector graphics in hyperview
Hi David,
You can capture images with JPEG, BMP, tiff, PNG file format extension. .eps file is not currently supported.
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Re: Odd SPC force output at topologie optimization analysis
Hi linus,
Have you calculated the reaction forces using total mass (deisgn and non-design mass)?. I see you have design and non-design components for optimization.
could you please share the solver deck? please use the following dropbox to share your model:
https://ftin.india.altair.com:8443/filedrop/~BDR1DN
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Re: how to solve the ZERO OR NEGATIVE VOLUME problem when using very soft material?
I have sent all the files. Hope they help you understand.. The engine file inputs I am using are : /parith ON, /print -1000, /rfile 5000, /tfile 8e-5, /Anim/DT freq 5e-5, Tstop 2e-2
Thanks.. :-)
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Re: how to solve the ZERO OR NEGATIVE VOLUME problem when using very soft material?
Also how to get the results for strain energy of components and Impact force Vs time and impact force vs deformation curve?
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Re: how to solve the ZERO OR NEGATIVE VOLUME problem when using very soft material?
Hi,
in TYPE7 card, change the Istiff to 4 and run the analysis. you can also specify a stiffness factor (STFAC)
Istiff 4 takes the minimum stiffness of master and slave.
hope this helps :)
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Re: Optistruct with fabric prepreg
Hi,
can you confirm this, E1 and E2 values you have are the young's modulus values in warp and weft direction?
can you define the "LAMINATE" of your model?
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Re: how to create vector graphics in hyperview
Hi David,
You can do this easily with freeware, see the attached video that uses a free ware called pdf creator. (rename the video attached as jpg below to wmv)
The video is only for demonstration, please check with pdf creator about its licensing and use. we cannot be responsible for external software and its effects. http://www.pdfforge.org/pdfcreator
If you make the pdfcreator for example the default printer, then you can use the keyboard shortcut of ctrl + f3 or ctrl + f1 to print from HyperView.
![Image]()
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Re: Odd SPC force output at topologie optimization analysis
Hey,
I uploaded my *.fem file.
For calculating the reaction force i took the mass (4.966E-03) from the *.out file. I assume that this is the total mass. At least the equation
Total Mass of Design Material * Design Volume Fraction + Mass of Non-Design Material = Massis okay.
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Re: Print Postscript
You can do this easily with freeware, see the attached video that uses a free ware called pdf creator. (rename the video attached as jpg below to wmv)
The video is only for demonstration, please check with pdf creator about its licensing and use. we cannot be responsible for external software and its effects. http://www.pdfforge.org/pdfcreator
If you make the pdfcreator for example the default printer, then you can use the keyboard shortcut of ctrl + f3 or ctrl + f1 to print from HyperView.
![Image]()
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Re: Print Postscript
Note while saving you can choose the file format type to .eps, not doing so will save in the default pdf format.
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Re: how to create vector graphics in hyperview
Note while saving you can choose the file format type to .eps, not doing so will save in the default pdf format.
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Linear and Non linear analysis, iteration, increment, step etc explanation
The equation of motion for a static analysis is as below:
[K] {X} = {F} ------------------------------------------ (1)
[K] --> Global Stiffness Matrix
{X} --> Unknown Displacement
{F} ---> External Force Applied.
For the body to be in static equilibrium, the net force acting at every node must be zero. Therefore, the basic statement of static equilibrium is that the internal forces, I, and the external forces, F, must balance each other:
[K] {X} is nothing but internal force 'I'
Equation (1) now becomes,
==> I = F or I - F = 0 -----------------------------------(2)
In Dynamic Analysis, the imbalance between the external and internal forces results in an acceleration:
F - I = M a.
F --> External Forces
I ---> Internal Force
M*a --> Inertial Forces (mass times acceleration)
In linear static analysis the stiffness matrix is constant and shall not change/update throughout the analysis. There are many check need to be performed once you have linear static results for well conditioned problems.
The equation (1) is decomposed one time to find the unknown displacement.
[K] {X} ={F}
After decomposition, a singularity may lead to an incorrect solution. In static analysis to obtain {X} (displacements). Using these displacements, One can calculate a “residual” loading vector as follows:
[K] {X} -{F} =δ F
This residual vector should theoretically be null (equation 2) but may not be null due to numeric roundoff.
In Nonlinear static analysis, The stiffness matrix changes in each and every iteration since the stiffness matrix is dependent on the external load. The external load in Nonlinear static analysis is applied in increments and time here has no physical meaning.
Time is just a convenient way to apply full load in nonlinear static analysis. In Optistruct the incremental load is controlled by 'NINC' field in the NLPARM card for NLSTAT load steps, this is a fixed load increment method.
If you add the PARAM,EXPERTNL,YES to the deck, the time increment method becomes automatic in which case, the increment (load) is increased or cut back based on the convergence rate.
NLGEOM loadstep has automatic time step by default. In NLGEOM loadstep the RAMP load curve can be defined using TABLED1 card and then refer this in NLOAD1 card.
In nonlinear static analysis, OptiStruct uses the Newton-Raphson method to obtain solutions for nonlinear problems to maintain the residuals close to zero (equation 2)
In a nonlinear analysis the solution usually cannot be calculated by solving a single system of equations, as would be done in a linear problem. Instead, the solution is found by applying the specified loads gradually and incrementally working toward the final solution. Therefore, OptiStruct breaks the simulation into a number of load increments (NINC) and finds the approximate equilibrium configuration at the end of each load increment.
It is important that you clearly understand the difference between an analysis step (NLSTAT / NLGEOM), a load increment (NINC of NLPARM card), and an iteration (MAXITER of NLPARM card)
The load history for a simulation consists of one or more steps. Within a step you will have many no of increments (NINC), within increment there can be many no. of iteration (MAXITER). OptiStruct checks the equilibrium equation ( equation 2) for each and every iteration. If the solution from an iteration is not converged, OptiStruct performs another iteration to try to bring the internal and external forces into balance.
An increment is part of a step. An iteration is an attempt at finding an equilibrium solution in an increment when solving with an implicit method. If the model is not in equilibrium at the end of the iteration, OptiStruct tries another iteration. With every iteration the solution OptiStruct obtains should be closer to equilibrium; sometimes OptiStruct may need many iterations to obtain an equilibrium solution. When an equilibrium solution has been obtained, the increment is complete.
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