Multiple iterations for plotting

Hello dear,

I would like to request for your assistance to set a clear command for executing the iterations to plot the structural parameters in the code below. The code is not executing the needed iterations. The output is turning out only one value. I am hoping a single line of command will resolve the issue.

h= 0.5;

b = 0.5;

d1= 0.474;

d2= 0.035;

As= 2512*10^-6;

Asc= 2512*10^-6;

fy= 400*10^6;

Es= 200*10^9;

fc= 30*10^6;

fcd= 0.85*fc/1.5;

ecu= 0.0035;

ey= fy/Es;

for z= -1:0.3:2

es1= z*ey;

c= ecu * d1/(ecu - es1);

es2= ecu * (c - d2)/c;

fs1= es1 * Es;

fs2= es2 * Es;

end

if fs1> fy && fs1< -1*fy

fs1= fy;

%else fs1= fs1;

end

if fs2> fy && fs2< -1*fy

fs2= fy;

%else fs2= fy;

end

if fc<= 30

beta= 0.85;

else

beta= max (0.85 - 0.05*(fc-30)/7, 0.65);

end

% if c> h

% c = h;

% end

a= beta*c;

if a> h

a = h;

end

cb= d1 * (ecu/(ecu + ey));

Fcc= 0.85*fcd*a*b;

Fs= fs1 * As;

Fsc = fs2 * Asc;

if c >= cb

phi= 0.7;

elseif c < cb

phi= 0.9;

end

Nsd= phi*(0.85*fcd*a*b - fs1*As + fs2*Asc);

Msd= phi*(Fcc*(h/2-a/2) + Fsc*(h/2-d2) + Fs*(d1-h/2));

plot (Msd, Nsd);

xlabel ('Msd, kNm');

ylabel ('Nsd, kN');

title ('interaction diagram');

Answer 1

[Torsten]

Maybe you mean

h= 0.5;
b = 0.5;
d1= 0.474;
d2= 0.035;

As= 2512*10^-6;
Asc= 2512*10^-6;
fy= 400*10^6;
Es= 200*10^9;
fc= 30*10^6; 
fcd= 0.85*fc/1.5;
ecu= 0.0035;
ey= fy/Es;
i = 0;
for z= -1:0.3:2
    i=i+1;
    es1= z*ey;
    c= ecu * d1/(ecu - es1);
    es2= ecu * (c - d2)/c;
    fs1= es1 * Es;
    fs2= es2 * Es;
%end
if fs1> fy && fs1< -1*fy
    fs1= fy;
    %else fs1= fs1;
end

if fs2> fy && fs2< -1*fy
    fs2= fy;
    %else fs2= fy;
end

if fc<= 30 
    beta= 0.85;
else
    beta= max (0.85 - 0.05*(fc-30)/7, 0.65);
end

% if c> h
%     c = h;
% end

a= beta*c;
if a> h
    a = h;
end

cb= d1 * (ecu/(ecu + ey));

Fcc= 0.85*fcd*a*b;
Fs= fs1 * As;
Fsc = fs2 * Asc;

if c >= cb
    phi= 0.7;
elseif c < cb 
    phi= 0.9;
end

Nsd(i)= phi*(0.85*fcd*a*b - fs1*As + fs2*Asc);
Msd(i)= phi*(Fcc*(h/2-a/2) + Fsc*(h/2-d2) + Fs*(d1-h/2));
end
plot (Msd, Nsd);
xlabel ('Msd, kNm');
ylabel ('Nsd, kN');
title ('interaction diagram');

But what about these if-statements ?

if fs1> fy && fs1< -1*fy
    fs1= fy;
    %else fs1= fs1;
end

if fs2> fy && fs2< -1*fy
    fs2= fy;
    %else fs2= fy;
end

How can a number be > 400*10^6 and at the same time be < -400*10^6 ?

[Sam]

Dear Torsten,

Your first comment above has helped me iterate Nsd. Thank you very much. Now only Msd remains to be iterated. Any insight?

[Sam]

Dear Torsten,

By dropping the semicolon after the formulas for Msd and Nsd, now the iterations for both values are coming up. But the plot is not showing the expected graph.