XANSYS Message: 38567 [Go back to message list] [bookmark on del.icio.us]
No rating yet Subject: Re: Optimizing section capacity Author: Yaser Jaradat Date: 2002-06-06 14:22:00I understand that logic. but this is the problem, I have a section of composite layers and I want optimize it for maximum capacity through fiber oriention....So what should be my objective function if it is not P ?
Also I thought of an other OBJ function other than P and related to P, like deformation or stress! Just I wanted to know if it works with P as an objective function, but it seems not.
Yaser Jaradat Dept. of Civil Engineering University of Maryland College Park, MD 20742 Phone: 301-405-1952
shenyeh_chen wrote:
> I don't think it will work.......
> P is an objective function, which means it has to be evaluated in the > process. In your input, the only action to evaluate > P is
> "P=10"
> So P will be 10 forever. A Constant. How can you > minimize/maximize a constant ?
> You will have to understand your problem more. The capacity should > be a function of the load you apply, among other things (like > fiber orientation, ply thichness, etc) not the load itself. > Defining the load you are alreafy applying as a value to optimize is > not making any sense. You probably want to optimize some response > caused by the load (???).
> --- In xansys@y..., Yaser Jaradat wrote: > > Shen-Yeh,
> > Don't worry about me, I will not get heart burned, I have a lot of > water to cool it ....:) ...Its just a matter > > of misscommunication.
> > Regarding my problem, when I said didn't work I meant that when I > assigned the applied nodal load as an > > objective function it didn't work ...what I wanted to know is if > ansys can accept an input parameter as an > > objective function for optimization or not. Or it has to be a > variable to be calculated within the process like, > > Volume, Area, Stress, buckling load....etc.
> > P=10 initial applied load
> > Nsel, nodes on which load applied > > F,all,FY, P/(selected nodes)
> > Solve
> > /opt
> > opvar,theta,dv
> > opvar, stress,sv
> > opvar,OBJ, P. ?? will this work ?
> > Yaser Jaradat > > Dept. of Civil Engineering > > University of Maryland > > College Park, MD 20742 > > Phone: 301-405-1952
> > shenyeh_chen wrote:
> > > Yaser,
> > > Don't get heart burn because of this. If you are posting on > > > fea-optimization or LS-DYNA group, you will be asked to identity > > > yourself too (or you will be totally ignored). I even got kicked > out > > > of this group few weeks back because my eamil address looks like a > > > free one. So I had to change my email to my company address.
> > > Capacity of composite can be tricky, and you have to define what > > > you mean by "capacity" first. It can be the compliance, can be > > > the stiffness, or it can be the damage level.
> > > There are a lot of situation that we can catagorized as "not > > > working" in optimizaiton. Either it doesn't reach a feasible > solution, > > > or it doesn't give an optimum solution, or it gives a wrong > solution, > > > or it escapes from your desired design space, or it never > converges > > > and iterates forever. Which one is your situation ?
> > > remember that optimization is not only a nonlinear problem, it is > > > an "inequality" problem too. So the way you formulate it will be > > > very important.
> > > --- In xansys@y..., "Bohlen, Dan (GEAE)" wrote: > > > > Sorry, nationality does count. Ansys is not available in > certain > > > countries > > > > therefore people who post from those countries cannot have a > > > legitimate copy of > > > > the program. We don't like to help those with cracked copies of > > > Ansys.
> > > > On a less legal angle, it's just polite to know who you are > talking > > > to.
> > > > You should have asked me this question long time ago because I > am > > > writing to the > > > > group almost everyday and I am > > > > getting responses most of time. Regarding who am I and where > from, I > > > think all > > > > of us are using this group to > > > > share knowledge and information doen't matter the race or > > > nationality. The > > > > response should not based on such > > > > thing. Also I am attaching a signature with my information in > all > > > my emails.
> > > > Yaser Jaradat > > > > Dept. of Civil Engineering > > > > University of Maryland > > > > College Park, MD 20742 > > > > Phone: 301-405-1952
> > > > shenyeh_chen wrote:
> > > > > If you tell us who you are, and where your are from, you will > > > probably > > > > > get more response.
> > > > > Optimizing the composite fiber orientation is an old topic in > > > > > optimization. You should do a paper search.
> > > > > If you are doing research on this field, you should probably > try > > > to > > > > > figure out the formulation by yourself.
> > > > > > I asked this quetion yesterday about maximizing the load > > > capacity > > > > > for a built up section by using the load > > > > > > which is an input parameter as and OBJ variable.....I tired > it > > > but > > > > > didn' work !
> > > > > > Any comments on that ?
> > > > > > Yaser
> > > > > > Nanjudareddy wrote:
> > > > > > > Hi
> > > > > > > Please cross check your material properties and and units. > > > > > > > we have run the model with different material properties > and > > > found > > > > > the > > > > > > > conduction through out the length.
> > > > > > > At 06:57 AM 06/06/2002 -0000, you wrote: > > > > > > > >Dear Xansys Users: > > > > > > > >First: In reply to some suspicius xansys users I must say > > > that: > > > > > > > >This is not homework. I'm writing a manual to teach > Thermal > > > > > Analysis > > > > > > > >with Ansys for Engineering, Masters and PhD Students. > > > > > > > >Should you not belive this you can visit > > > > > > > >http://usuarios.lycos.es/el1max/Proyec_Sec/ > > > > > > > >where I keep a buckup of some of my files. (In spanish) > > > > > > > >I please ask you not to spread those files for they are > my > > > work. > > > > > > > >It's my project and I have to read it by July and so I > need > > > help. > > > > > > > >If still you are not a beliver you can bother to contact > my > > > > > thesis > > > > > > > >director Pedro Di‚guez, Dean of the Engineering School at > the > > > > > > > >Universidad Publica de Navarra. Pamplona. Navarra. Spain. > > > > > > > >http://www.unavarra.es/organiza/etsiit/
> > > > > > > >Thus said I'm sorry for not having followed the nettique > > > about > > > > > > > >signing the mail. At least I said what the topic was on > the > > > > > subject. > > > > > > > >Now I repost my question. > > > > > > > >Thank you for your help.
> > > > > > > >Hello: > > > > > > > >I'm trying to make a transint thermal analysis of a pipe. > > > > > > > >The pipe is a the begining at -20C and the a fluid flows > in > > > the > > > > > > > >inside with h=500 and t Fluid=60. > > > > > > > >The outside of the pipe is insulated > > > > > > > >The model is 3D using solid 90. > > > > > > > >For some reason the head is not conducted from 1 element > to > > > the > > > > > next. > > > > > > > >ANy idea why?? > > > > > > > >Thank you very much: > > > > > > > >Here is the log: