%% Function name
%       stresslocallaminate

%% Revised
%       3 February 2014

%% Authors
%       Prashanth Sridharan, Trey Moore, & Autar Kaw 
%       Section: All
%       Semester: Fall 2013

%% Purpose 
%       Given the number of angle plies, the angle of each ply, and the
%       global stress of each of the plies, output the global stresses for each ply  

%% Usage
%       function [stresslocalplies] = stresslocallaminate(stressglobalplies,angleplies,nplies)
% Input variables
%       stressglobalplies=global stress at top, middle, and bottom of each laminate
%       nplies=number of plies
%       angleplies=angle of each ply
% Output variables
%       stresslocalplies=local stress at top, middle, and bottom of each laminate
% Keyword
%       global strain
%       global stress

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

%% Code     
function [stresslocalplies] = stresslocallaminate(stressglobalplies,angleplies,nplies)
% TREY: Move all comments to separate lines

for k=1:nplies  %loop to calculate for ply k
    % Angle of ply
    angle= angleplies(1,k);
    % Calculating the sine of the desired angle
    s=sind(angle);
    % Calculating the cosine of the desired angle
    c=cosd(angle);
    for i=1:3
        % Global stress in each direction
        sigx=stressglobalplies(i,1,k);
        sigy=stressglobalplies(i,2,k);
        sigxy=stressglobalplies(i,3,k);
        % Local stress in each direction
        stresslocalplies(i,1,k) = (c^2)*sigx + (s^2)*sigy + 2*s*c*sigxy;
        stresslocalplies(i,2,k) = (s^2)*sigx + (c^2)*sigy + (-2)*s*c*sigxy;
        stresslocalplies(i,3,k) = (-1)*s*c*sigx + s*c*sigy + (c*c - s*s)*sigxy;    
    end
end
end