function[ufc,lb,ab,hb,st] = opt(m,mt,smax,lmax,wmax)
%optimise blade design from available thicknesses of steel and stress, length and width
%given stage and total load
g = 9.81; %gravitational acceleration
alpha = 1.38; %shape factor  ?????????????????
ye    = 186e9; %Young's elastic modulus for Marval steel blades
mtb = mt;%total load on one blade
mb  = m;%uncoupled mass on one blade
lb = lmax; %always best
for index = 1:12

    %NOTE CHANGE !!!! 0.0005 to 0.0001!!!!!!!!!!
    
   h = 0.0005 + index*0.0001;   %changed as possibility can get material to 0.1mm and not 0.5mm
   
   for jndex = 1:18
      a = 0.02+(wmax-0.02)/18*jndex;  
      s = 6.*mtb.*g.*lb./(a.*h.^2);%max stress at equilibrium
      d = 4.*mtb.*g.*lb.^2.*alpha./(ye.*a.*h.^3); %deflection unloaded /l
      if s < smax & d < pi/2
         f(index,jndex) = sqrt(ye.*a.*h.^3./(4.*mb.*lb.^3.*alpha))./2./pi; %mode freq.
         stress(index,jndex) = s;
      else 
         f(index,jndex) = NaN;%invalidate 
         stress(index,jndex) = s;
      end
   end
end
[fmin1,index1] = min(f);
[fmin2,index2] = min(fmin1);
ufc = fmin2;
aindex = index2;
ab     = 0.02+(wmax-0.02)/18*aindex;  
hindex = index1(aindex);

%NOTE CHANGE !!!! 0.0005 to 0.0001!!!!!!!!!!
hb = 0.0005 + hindex*0.0001; 

st = stress(hindex,aindex);