Re: need your help
- To: mathgroup at smc.vnet.net
- Subject: [mg118410] Re: need your help
- From: Oliver Ruebenkoenig <ruebenko at wolfram.com>
- Date: Wed, 27 Apr 2011 05:38:25 -0400 (EDT)
On Sun, 24 Apr 2011, Arezoo Sadrinezhad wrote: > Hello Mathematica Friends, > > I am stuck with this problem, where I use NDSolve[] to solve a partial > differential equation. > > The error is: NDSolve::ndnum: Encountered non-numerical value for a > derivative at t==0! > > The sample code is below. > > Please suggest me ways to solve this problem. Thank > you. > > > -- > Best regards, > > Arezoo Sadrinezhad > Ph.D. Student > Department of Civil Engineering > University of Akron > Akron, Ohio 44325-3905 > Email: as144 at zips.uakron.edu <mailto:as144 at zips.uakron.edu> > > This is my code: > > AC11=10; > > AC22=5; > > DC1111=25; > > DC2222=6.25; > > LB=-0.06; > > RB=0.1; > > > > StressIC[s11_,s22_]:=Limit[(1/((2Pi)*c*c))*Exp[-(1/2)*(((s11-0)/c)^2+((s22-0)/c)^2)],c->0.001]; > > Plot3D[StressIC[s11,s22],{s11,-0.1,0.1},{s22,-0.1,0.1},AxesLabel->{"sigma11","sigma22","P[s11,s22,0]"}] > > > > YieldStressDistribution=NormalDistribution[0.05,0.5*0.05]; > > CDF[YieldStressDistribution,h] > > Plot[CDF[YieldStressDistribution,h],{h,-0.2,0.2}] > > YF[s11_,s22_]=Abs[s11-s22]; > > cumuldist[s11_,s22_]=0.5*(1+Erf[28.2843*(-0.05+YF[s11,s22])]) > > Plot3D[cumuldist[s11,s22],{s11,-0.4,0.4},{s22,-0.25,0.25},PlotRange->All] > > > > AC11p[s11_,s22_]=AC11*(1-cumuldist[s11,s22]) > > AC22p[s11_,s22_]=AC22*(1-cumuldist[s11,s22]) > > DC1111p[s11_,s22_]=DC1111*(1-cumuldist[s11,s22]) > > DC2222p[s11_,s22_]=DC2222*(1-cumuldist[s11,s22]) > > > > ElasticPlasticEq={D[AC11p[s11,s22]*P[s11,s22,t],s11]+2*D[AC22p[s11,s22]*P[s11,s22,t],s22]+D[P[s11,s22,t],t]-D[DC1111p[s11,s22]*P[s11,s22,t]*t,{s11,2}]-2*D[DC2222p[s11,s22]*P[s11,s22,t]*t,{s22,2}]==0,P[s11,s22,0]==StressIC[s11,s22], > > AC11p[LB,s22]*P[LB,s22,t]-(D[DC1111p[s11,s22]*P[s11,s22,t]*t,s11]/. > s11->LB)==0, > > AC11p[RB,s22]*P[RB,s22,t]-(D[DC1111p[s11,s22]*P[s11,s22,t]*t,s11]/. > s11->RB)==0, > > 2*AC22p[s11,LB]*P[s11,LB,t]-2*(D[DC2222p[s11,s22]*P[s11,s22,t]*t,s22]/. > s22->LB)==0, > > 2*AC22p[s11,RB]*P[s11,RB,t]-2*(D[DC2222p[s11,s22]*P[s11,s22,t]*t,s22]/. > s22->RB)==0} > > Off[General::stop]; > > > > t=.; > > ElasticPlasticSol=NDSolve[ElasticPlasticEq,P[s11,s22,t],{s11,LB,RB},{s22,LB,RB},{t,0,0.03}, > StepMonitor:>Print[t],SolveDelayed->True] > > > > I would be really grateful if you could help me! I really get stuck. > >> >> On 04/23/11 18:01, Arezoo Sadrinezhad wrote: >> >>> Hello Mathematica Friends, >>> >>> I am stuck with this problem, where I use NDSolve[] to solve a partial >>> differential equation. >>> >>> The error is: NDSolve::ndnum: Encountered non-numerical value for a >>> derivative at t==0! >>> >>> The sample code is attached to this email. >>> >>> Please suggest me ways to solve this problem. Thank >>> you. >>> >>> >>> -- >>> Best regards, >>> >>> Arezoo Sadrinezhad >>> Ph.D. Student >>> Department of Civil Engineering >>> University of Akron >>> Akron, Ohio 44325-3905 >>> Email: as144 at zips.uakron.edu <mailto:as144 at zips.uakron.edu> >>> >> > > > Hello, I can not reproduce the error message: I get the following NDSolve::delpde: Delay partial differential equations are not currently supported by NDSolve Oliver