%% Function name
%       beta_gtol
    
%% Revised
%       15 January 2014

%% Author
%       Younes Benkabbou, Trey Moore, & Autar Kaw
%       Section: All
%       Semester: Fall 2012

%% Purpose
%       Given the longitudinal and transverse coefficients of moisture 
%       expansion of a unidirectional lamina, and the angle of the ply, 
%       this function outputs the coefficients of moisture expansion for 
%       an angle lamina.

%% Usage 
%       function [betaxy] = beta_gtol(beta12, angle)
% Input variables
%       beta12=vector of moisture expansion of unidirectional lamina 
%               in 1,2 direction 
%       [beta12]=[beta1;beta2;zero]
%       beta1=longitudinal coefficient of moisture expansion.
%       beta2=transverse coefficient of moisture expansion.
%       beta12=in-plane coefficient of moisture expansion.
%       angle=angle of ply given in degrees.
% Output variables
%       betaxy=vector of coefficients of moisture expansion for angle
%               in x,y direction
%       [betax,betay,betaxy]

% Keyword
%       coefficient of moisture expansion
%       angle ply

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

%% Testing Code
clc
clear all
%% Inputs
% Material:  Glass/Epoxy
beta1=0;
beta2=0.6;
[beta12]=[beta1;beta2;0];
fprintf('\nLongitudinal Coeff. of Moisture Expansion: %g ',beta1)
fprintf('\nTransverse Coeff. of Moisture Expansion: %g ',beta2)
%% Test 1
% Testing for individual angle
% Input desired angle in degrees
angle=60;
% Call function: beta_gtol
[betaxy] = beta_gtol(beta12,angle);
% Results for a particular angle
fprintf('\n\nAngle of Lamina: %G\n\n',angle)
disp('   Lamina Coefficient of Moisture Expansion')
disp('________________________________________________')
fprintf('\n betax   | %G\n betay   | %G\n betaxy  | %G\n\n\n\n',...
    betaxy(1),betaxy(2),betaxy(3))
%% Test 2
% Table of Moisture Expansion Coefficients of an Angle Lamina
% as a Function of Fiber Angle
for i=1:5:91
    angle(i)=i-1;
    [betaxy] = beta_gtol(beta12,angle(i));
    betax(i)=betaxy(1);
    betay(i)=betaxy(2);
    beta_xy(i)=betaxy(3);
end
disp('          Lamina Coefficient of Moisture Expansion')
disp('_________________________________________________________________')
disp('  angle          betax              betay           betaxy  ')
for i=1:5:91
   fprintf('\t%2.0f |\t  %E |\t %E |\t %E \n', angle(i),betax(i),betay(i),beta_xy(i))
end
%% Test 3
% Graph of Moisture Expansion Coefficients of an Angle Lamina
% as a Function of Fiber Angle
for i=1:1:91
    angle(i)=i-1;
    [betaxy] = beta_gtol(beta12,angle(i));
    betax(i)=betaxy(1);
    betay(i)=betaxy(2);
    beta_xy(i)=betaxy(3);
end
hold on
plot(angle,betax,'b','LineWidth',2)
plot(angle,betay,'r','LineWidth',2)
plot(angle,beta_xy,'m','LineWidth',2)
grid
legend('betax','betay','betaxy')
title('Coefficient of Moisture Expansion vs. Fiber Angle')
xlabel('Angle (degrees)')
ylabel('Coefficient of Moisture Expansion')
hold off