for loop to draw while loop ()

%now P =700 ct number but I want to get same result for different P (600,700,900) in the same graph to make comparaision ,how can I plot it ?

clear all

close all

a=15;

b=60;

c=18.4;

Sy=1070;

P=700;

Py=501;

r=[a:0.01:b];

n=1;

%stress after loading

%plastic

while(r(n)<c)

%plastic region(ri<r<rp)

Sr(n)=-(Sy/2)*((P/Py)*(1-(a^2/r(n)^2))-log(r(n)^2/a^2));

So(n)=-(Sy/2)*((P/Py)*(1+(a^2/r(n)^2))-(2+log(r(n)^2/a^2)));

n=n+1;

end

%elastic

while (r(n)>=c)

%elastic region(rp<r<rp)

Sr(n)=-(Sy/2)*(((c^2/a^2)-(P/Py))*((a^2/r(n)^2)-(a^2/b^2)));

So(n)=(Sy/2)*(((c^2/a^2)-(P/Py))*((a^2/r(n)^2)+(a^2/b^2)));

n=n+1;

if n>length(r)

break

end

end

figure(1)

plot(r,Sr,'r',r,So,'b')

grid on

grid minor

[David Hill]

a=15;
b=60;
c=18.4;
Sy=1070;
P=[600,700,900];
Py=501;
r=[a:0.01:b];
%stress after loading 
%plastic
for k=1:3
    n=1;
    while(r(n)<c)
    %plastic region(ri<r<rp)
    Sr(n,k)=-(Sy/2)*((P(k)/Py)*(1-(a^2/r(n)^2))-log(r(n)^2/a^2));
    So(n,k)=-(Sy/2)*((P(k)/Py)*(1+(a^2/r(n)^2))-(2+log(r(n)^2/a^2)));
    n=n+1;
    end
    %elastic
    while (r(n)>=c)
    %elastic region(rp<r<rp)
    Sr(n,k)=-(Sy/2)*(((c^2/a^2)-(P(k)/Py))*((a^2/r(n)^2)-(a^2/b^2)));
    So(n,k)=(Sy/2)*(((c^2/a^2)-(P(k)/Py))*((a^2/r(n)^2)+(a^2/b^2)));
    n=n+1;
    if n>length(r)
        break
    end
    end
end
 
figure(1)
plot(r,Sr(:,1),r,Sr(:,2),r,Sr(:,3),r,So);%whatever colors ...
grid on
grid minor

[Mohamad Mourad]

Hello David fistly thanks you for your answers I have just a last question if c=[18.35,20.35,22.72]; like p

this mean for each p we have different c

Sr(n,k)=(-Sy/sqrt(3))*((c(k)^2/a^2)-(P(k)/Py))*((a^2/r(n)^2)-(a^2/b^2));

So(n,k)=(Sy/sqrt(3))*((c(k)^2/a^2)-(P(k)/Py))*((a^2/r(n)^2)+(a^2/b^2));

i tried to write it like that but this make error in matrix

should i make new counter for c also ?

[David Hill]

Works for me.

a=15;
b=60;
c=[18.35,20.35,22.72];
Sy=1070;
P=[600,700,900];
Py=501;
r=[a:0.01:b];
%stress after loading 
%plastic
for k=1:3
    n=1;
    while(r(n)<c(k))
    %plastic region(ri<r<rp)
    Sr(n,k)=-(Sy/2)*((P(k)/Py)*(1-(a^2/r(n)^2))-log(r(n)^2/a^2));
    So(n,k)=-(Sy/2)*((P(k)/Py)*(1+(a^2/r(n)^2))-(2+log(r(n)^2/a^2)));
    n=n+1;
    end
    %elastic
    while (r(n)>=c(k))
    %elastic region(rp<r<rp)
    Sr(n,k)=-(Sy/2)*(((c(k)^2/a^2)-(P(k)/Py))*((a^2/r(n)^2)-(a^2/b^2)));
    So(n,k)=(Sy/2)*(((c(k)^2/a^2)-(P(k)/Py))*((a^2/r(n)^2)+(a^2/b^2)));
    n=n+1;
    if n>length(r)
        break
    end
    end
end
 
figure(1)
plot(r,Sr(:,1),r,Sr(:,2),r,Sr(:,3),r,So);%whatever colors ...
grid on
grid minor