%% Function name
%       midplane

%% Revised:
%       28 January 2014

%% Author
%       Swamy Rakesh Adapa, Trey Moore, & Autar Kaw
%       Section: All
%       Semester: Fall 2013

%% Purpose
%       Given the midplane extensional, coupling and bending stiffness 
%       matrices of the laminate, mechanical and fictitious hygrothermal 
%       force & moment vectors, output the midplene 
%       strains and curvatures

%% Usage
%       function [eps0,kappa] = midplane(A,B,D,NM,MM,NT,MT,NC,MC)
% Input variables
%       A=extensional stiffness matrix 
%       B=coupling stiffness matrix
%       D=bending stiffness matrix
%       NM=vector of mechanical forces
%       MM=vector of mechanical moments
%       NT=vector of fictitious thermal forces
%       MT=vector of fictitious thermal moments
%       NC=vector of fictitious moisture forces
%       MC=vector of fictitious moisture moments
% Output variables
%       eps0=midplane strains
%       kappa=midplane curvatures 
% Keyword
%       stiffness matrix
%       mechanical load
%       hygrothermal load
%       midplane strains
%       midplane curvatures

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

%% Testing code
clc
clear all
%% Inputs
% Lamina: 30/45/60
% Material: Graphite/Epoxy
[A]=[2.371E7 1.341E7 1.464E7;1.341E7 2.371E7  1.464E7;1.464E7  1.464E7 1.501E7];
[B]=[-1.340E3 1.705E-13 -5.334E2;1.705E-13 1.340E3 5.334E2;-5.334E2 5.334E2 2.274E-13];
[D]=[2.907E-1 1.443E-1 1.641E-1;1.443E-1 2.907E-1 1.641E-1;1.641E-1 1.641E-1 1.630E-1];
NM=[4;5;1.5E1];
MM=[7;8;1.1E1];
NT=[6.787E3;6.787E3;-3.361E3];
MT=[1.538E-1;-1.538E-1;-2.220E-16];
NC=[1.490E7;1.490E7;-7.632E6];
MC=[3.492E2;-3.492E2;-9.095E-13];
disp('Extensional Stiffness Matrix:')
disp('______________________________________________')
disp(A)
disp('Coupling Stiffness Matrix:')
disp('______________________________________________')
disp(B)
disp('Bending Stiffness Matrix:')
disp('______________________________________________')
disp(D)
disp('Mechanical Forces:')
disp('______________________')
disp(NM)
disp('Mechanical Moments:')
disp('______________________')
disp(MM)
disp('Fictitious Thermal Forces:')
disp('______________________________')
disp(NT)
disp('Fictitious Thermal Moments:')
disp('______________________________')
disp(MT)
disp('Fictitious Moisture Forces:')
disp('______________________________')
disp(NC)
disp('Fictitious Moisture Moments:')
disp('______________________________')
disp(MC)
%% Test
% Call function: midplane
[eps0,kappa] = midplane(A,B,D,NM,MM,NT,MT,NC,MC);
% Midplane strains
disp('Extensional Stiffness Matrix:')
disp('__________________________________')
disp(eps0)
% Midplane curvatures
disp('Coupling Stiffness Matrix:')
disp('___________________________________')
disp(kappa)