Error in solving an equation

Hi everyone,

i would like to solve an equallity of two equations that the varaible is "c".

equation 1 - compression

equation 2 - tension

i would like to solve: tension=compression and find out "c"

Thank You

b=300;  %mm
d=400;  %mm
fc=40;  %Mpa
Ecm=22*(fc/10)^0.3*10^3;  %Mpa
Es=200000;  %Mpa
epsc1=min(2.8/1000,0.7*fc^0.31/1000);
epscu=3.5/1000;
k=1.05*Ecm*epsc1/fc;

epscm=1.5/1000;
funC=@(epsc) (k*epsc/epsc1-(epsc/epsc1).^2)./(1+(k-2)*epsc/epsc1);
compression=@(c) b*fc*c/epscm*integral(funC,0,epscm)/1000;
tension=@(c) min(Es*(d-c)/c*epscm,fy);
solx=@(c) compression-tension;
x=solve(solx==0,c)

Answer 1

[Priyanshu Mishra]

Hi Shimon,

For solving the function handles, I would suggest you use fsolve. Following is the code with few changes which might help you:

b=300; %mm

d=400; %mm

fc=40; %Mpa

Ecm=22*(fc/10)^0.3*10^3; %Mpa

Es=200000; %Mpa

epsc1=min(2.8/1000,0.7*fc^0.31/1000);

epscu=3.5/1000;

k=1.05*Ecm*epsc1/fc;

fy = 1;

epscm=1.5/1000;

funC=@(epsc) (k*epsc/epsc1-(epsc/epsc1).^2)./(1+(k-2)*epsc/epsc1);

compression=@(c) b*fc*c/epscm*integral(funC,0,epscm)/1000;

tension=@(c) min(Es*(d-c)/c*epscm,fy);

solx=@(c) b*fc*c/epscm*integral(funC,0,epscm)/1000 - min(Es*(d-c)/c*epscm,fy);

x=fsolve(solx,0)