A.2. THE R-F METHOD FOR EXAMPLE 3.13 243
disp(ddp)
xlswrite('example3.11',ddp)
A.2 THE R-F METHOD FOR EXAMPLE 3.13
% The R-F method for example 3.13
% The Limit State function: g(T, d, Ssy)=Ssy*pi/10*d^3-T
% Input the distribution parameters dp1 and dp2
clear
mx=[34, 2.125, 31]; %The mean or the first distribution
%parameter
sx=[3,0.002,2.4]; %The standard deviation or the second
% distribution
%parameter
% Calculate the mean of T (Weibull) and the initial
% point x0(i)
x0(1)=mx(1)*gamma(1/sx(1)+1);
x0(2)=mx(2);
% The value of the last variable is determined by the
% limit state function
x0(3)=16*x0(1)/pi/x0(2)^3; % Equation (3.71) or (d)
beta=0; %set the beta =0
% Iterative process starting
for j=1:1000
% Calculate the equivalent mean and standard deviation
zteq=norminv(wblcdf(x0(1),mx(1),sx(1)));
steq=normpdf(zteq)/wblpdf(x0(1),mx(1),sx(1));
mteq=x0(1)-zteq*steq;
% Mean and standard deviation matrix
meq(1)=mteq;
seq(1)=steq;
for i=2:3
meq(i)=mx(i);
seq(i)=sx(i);
end
% Calculate z0(i)in the standrad normal distribution space
for i=1:3
z0(i)=(x0(i)-meq(i))/seq(i);
end