krata.m

% rozwiazanie MES
% przy uzyciu pakietu CALFEM 
%
% opracowal: Piotr Pluciński
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
% dane
E=1e6;
A=1e-2;
ep = [E A]
 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
% dyskretyzacja
LE=3; LW=3; LSSW=2; 
LSSU=LW*LSSW;
K=zeros(LSSU);
F=zeros(LSSU,1);
 
%wspolrzedne
Coord=[0 0; 3 0 ; 0 4];
 
% topologia 
% (przynaleznosc stopni swobody do ES)
% numery st.sw. dla wezlow
Dof=reshape((1:LSSU),LSSW,length(Coord))';
 
% macierz topologii
Etop=[1 2; 2 3; 1 3];
 
% definicja macierzy stopni swobody dla elementów
for i=1:LE
   Edof(i,:)=[i,Dof(Etop(i,1),:),Dof(Etop(i,2),:)];
end
 
[Ex,Ey]=coordxtr(Edof, Coord, Dof, 2);
 
% rysunek siatki ES
elnum=Edof(:,1);
eldraw2(Ex,Ey,[1,3,1],elnum);
 
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% obciazenie:
% siły węzłowe
F(6)=-10;
 
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% macierze i wektory ES
% agregacja
 
for i=1:LE
    Ke=bar2e(Ex(i,:),Ey(i,:),ep);
    K=assem(Edof(i,:),K,Ke);
end %for 
 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
% warunki brzegowe
bc=[1 0; 2 0; 4 -0.001; 5 0];
 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
%rozwiazanie
[Q,R]=solveq(K,F,bc)
 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
% postprocessing
% powrot do ES
% przemieszczenia w poszczegolnych ES
Qe=extract_ed(Edof,Q);
% rysunek zdeformowanej siatki ES
figure(1)
[sfac]=scalfact2(Ex,Ey,Qe,0.2);
eldisp2(Ex,Ey,Qe,[2,1,1],sfac);
 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
% obliczenie sił przywezłowych
for i=1:LE
  fe(i,:)=bar2s(Ex(i,:),Ey(i,:),ep,Qe(i,:));
end
fe
plotpar=[2 1];
 
% Siły podłuzne
figure(2)
[fmax,nmax]=max(fe);
scal=scalfact2(Ex(nmax,:),Ey(nmax,:),fe(nmax),0.1);
for i=1:LE
eldia2(Ex(i,:),Ey(i,:),ones(10,1)*fe(i,:),plotpar,scal);
end
%axis([-2 4 -1 5]);
title('sily podluzne')