%% Function name
%       straingloballaminate

%% Revised:
%       3 February 2014

%% Author
%       Kevin R. Johnson, Trey Moore, & Autar Kaw
%       Section: All
%       Semester: Fall 2013

%% Purpose
%       Given the mid-plane strains and curvatures as well as the thickness of
%       each ply, output the global strains at the top, middle, and bottom of
%       each laminate

%% Usage 
%       function [strainglobalplies] = straingloballaminate(eps0,kappa,nplies,tplies)
% Input variables
%       eps0=midplane strains 
%       kap=midplane curvatures
%       nplies=number of plies
%       tplies=thickness of each ply
% Output variables 
%       strainglobalplies=global strains at top, middle, and bottom of each laminate
% Keyword
%       strain-displacement equations
%       global strains
%       midplane strains and curvatures

%% License Agreement
%       http://www.eng.usf.edu/~kaw/OCW/composites/license/limiteduse.pdf

%% Code 
function [strainglobalplies]=straingloballaminate(eps0,kappa,nplies,tplies)
% Total thickness of lamina
t=sum(tplies);
% Top of first ply
z(1)=-t/2;
% Middle and Bottom of plies
for k = 1:nplies
    z(2)=z(1)+tplies(k)/2;
    z(3)=z(1)+tplies(k);
% Midplane strains and curvatures
    for j=1:3
       for i=1:3
          %strain-displacement equation
          strainglobalplies(i,j,k) = eps0(j) + z(i) * kappa(j); 
       end
    end
% Top of next ply
    z(1)=z(3);
end