Error with array bounds

Dear Community,

I am creating a function and unfortunately I dont know why I am getting this error "Index in position 1 exceeds array bounds." Can you please help me?

function [ABD_dome_2] = mt_laminate(Nsection,neutral_axis,Nplies)
%% Input Material Data
%% Laminate - Aluminum 2219 T6 alloy
%Nplies = 1; %Number of plies
E = 73800; % Young's Modulus in [N/mm^2]
t2 = 4.8; % Half Thickness of the thickest segment of the tank in [mm]
t1 = 1.5; % Thickness of the thinnest segment of the tank in [mm]
t = [1.5,4.8,2];
%% Temperature Gradients - Tank + Reinforcement Cylindrical Shell
deltaT = 0;
nu = 0.33; % Poisson's ratio
Coefficient = E/(1-nu^2);
% C matrix (material coordinates)- reduced stiffness matrix
Q = Coefficient * [1,nu,0;nu,1,0;0,0,(1-nu^2)/(2*(1+nu))];

%% Classical laminar theory
T = 25; % Temperature in [°C]
a = 1;
% m = 3; To use it in case I need HIBEF
Ai = zeros(3,3);
% A = cell(Nsection,1);
% B = cell(Nsection,1);
% D = cell(Nsection,1);
Bi = zeros(3,3);
Di = zeros(3,3);
NTi = zeros(3,1);
MTi = zeros(3,1);
Qbari = zeros(3,3);
NT_plot =[];
nt_plot = zeros(3,1);
ABD = cell(Nsection,1);
for n = 1:Nsection
    
    for m = 1:Nplies
        
        if (t(n)/2 - neutral_axis ==0)
            zbar(n) = 0 ;
            A{n,:} =  Ai + Q*t(n);
            B{n,:} = Bi + Q * t(n) * zbar(n);
            D{n,:} = Di + Q * (t(n) * zbar(n)^2  + t(n)^3 / 12);
            
            ABD1 = {A{n,:},B{n,:};B{n,:},D{n,:}};
            ABD11 = cell2mat(ABD1);
            %ABD{1,:}= {A,B;B,D};
            ABD{1,:} = ABD11;
        else
            zbar_up(n,:) = (t(n) - neutral_axis)/2;
            t_up(n,:) = (t(n) - neutral_axis);
            zbar_down(n,:) = (neutral_axis)/2;
            t_down(n,:) = neutral_axis;
            
            A_up{n,:} = Ai + Q * t_up(n,:);
            B_up{n,:} = Bi + Q * t_up(n,:) * zbar_up(n,:);
            D_up{n,:} = Di + Q * (t_up(n,:) * zbar_up(n,:)^2  + t_up(n,:)^3 / 12);
            
            A_down{n,:} = Ai + Q * t_down(n,:);
            B_down{n,:} = Bi + Q * t_down(n,:) * zbar_down(n);
            D_down{n,:} = Di + Q * (t_down(n,:) * zbar_down(n,:)^2  + t_down(n,:)^3 / 12);
            
            ABD_up{n,:} = {A_up{n,:},B_up{n,:};B_up{n,:},D_up{n,:}};
            ABD_up_Matrix = cell2mat(ABD_up{n,:});
            ABD_down{n,:} = {A_down{n,:},B_down{n,:};B_down{n,:},D_down{n,:}};
            ABD_down_Matrix = cell2mat(ABD_down{n,:});
            ABD{n,:} = ABD_up_Matrix - ABD_down_Matrix;
            
        end
        
    end
    
    %% Differential System Matrix
    
    ABD_cyl_15 = ABD{1,:};
    ABD_cyl_48 = ABD{2,:};
    ABD_dome_2 = ABD{3,:};
    
    %% 1.5 mm cylindrical Segment
    
    r_cyl = 550;
    
    
    A_cyl_15 = [0, 1/r_cyl - ABD_cyl_15(1,2)/(ABD_cyl_15(1,1) *r_cyl),0,1/(ABD_cyl_15(1,1)*r_cyl),0,0,0;
        1/r_cyl,0,1,0,0,0,0;
        0,0,0,0,0,1/(ABD_cyl_15(4,4)*r_cyl),0;
        0 , 0 , 0 , 0 , 1/r_cyl ,0,0;
        0 , ABD_cyl_15(2,2)/r_cyl - ABD_cyl_15(1,2)*ABD_cyl_15(2,1)/(ABD_cyl_15(1,1)*r_cyl), 0,- (1/r_cyl) + ABD_cyl_15(2,1)/(ABD_cyl_15(1,1)*r_cyl),0,0,0.36;
        0 , 0, 0, 0, -1, 0 ,0;
        0,0,0,0,0,0,0];
    
    for m = 1:90
        
        A_15_cell{m,:} =  A_cyl_15;
        
    end
    %% 4.8 mm cylindrical Segment
    
    rho = 1100;
    r_cyl = 550;
    A_48_cell = cell(60,1);
    A_48_cell{1,:} = zeros(7,7);
    % A_cyl_48(1,1) = - ABD_cyl_48(2,1) * ABD_cyl_48(4,4) + ABD_cyl_48(2,4) * ABD_cyl_48(1,4);
    %t2_a31 = - ABD_cyl_48(1,2)* ABD_cyl_48(1,4) + ABD_cyl_48(2,4)* ABD_cyl_48(1,1);
    %
    % t2_a41 = - ABD_cyl_48(2,1)*ABD_cyl_48(4,4)*ABD_cyl_48(1,2) + ABD_cyl_48(2,1)*ABD_cyl_48(1,4)*ABD_cyl_48(1,5) + ABD_cyl_48(2,4)*ABD_cyl_48(1,4)*ABD_cyl_48(1,2) - ABD_cyl_48(2,4)*ABD_cyl_48(1,5)*ABD_cyl_48(1,1);
    % t2_a46 = - ABD_cyl_48(2,1)* ABD_cyl_48(1,4) + ABD_cyl_48(2,4)*ABD_cyl_48(1,1);
    %
    % det_t2 = - ABD_cyl_48(1,1)* ABD_cyl_48(4,4) + ABD_cyl_48(1,4)^2;
    % A_cyl_48 =  [0, 1/r_cyl - ABD_cyl_48(1,2)/(ABD_cyl_48(1,1)*r_cyl),0,1/(ABD_cyl_48(1,1)*r_cyl),0,-ABD_cyl_48(1,4)/(det_t2*r_cyl),0;
    %         1/r_cyl,0,1,0,0,0,0;
    %         0,-(t2_a31)/(r_cyl*det_t2),0,-ABD_cyl_48(1,4)/(r_cyl*det_t2),0,-ABD_cyl_48(1,1)/(r_cyl*det_t2),0;
    %         0 , 0 , 0 , 0 , 1/r_cyl ,0,0;
    %         0 , (ABD_cyl_48(2,2)/r_cyl - 1/(r_cyl*det_t2)*(t2_a41)), 0,- 1/rho + (1* t2_a11)/(r_cyl*det_t2) ,0,-((1*t2_a46)/(r_cyl*det_t2)),0.36;
    %         0 , 0,  0 , 0, -1, 0,0;
    %         0,0,0,0,0,0,0];
    
    %
    %
    for i = 1:60
        
        A_48_cell{i,:} =[0,1/r_cyl - ABD_cyl_48(1,2)/(ABD_cyl_48(1,1) *r_cyl),0,1/(ABD_cyl_48(1,1)*r_cyl),0,0,0;1/r_cyl,0,1,0,0,0,0;0,0,0,0,0,1/(ABD_cyl_48(4,4)*r_cyl),0;0 , 0 , 0 , 0 , 1/r_cyl ,0,0;0 , ABD_cyl_48(2,2)/r_cyl - ABD_cyl_48(1,2)*ABD_cyl_48(2,1)/(ABD_cyl_48(1,1)*r_cyl), 0,- (1/r_cyl) + ABD_cyl_48(2,1)/(ABD_cyl_48(1,1)*r_cyl),0,0,0.36;0 , 0, 0, 0, -1, 0 ,0;0,0,0,0,0,0,0];
        
    end
    
end

Answer 1

[Robert Mende]

Would you please send the whole error message? It's problematic for anyone trying to help you find an error that might occur in any line that contains an array.

[Robert Mende]

How large are your arguments? Is Nsection>3 in any possible case? This will give you the error you posted about in the line " if (t(n)/2 - neutral_axis ==0)" as t has lenght 3.

[Marcelo Boldt]

>> mt_laminate(3,0.75,1)
Index in position 1 exceeds array bounds.

Error in mt_laminate (line 114)
 A_cyl_48 = [0, 1/r_cyl - ABD_cyl_48(1,2)/(ABD_cyl_48(1,1)
 *r_cyl),0,1/(ABD_cyl_48(1,1)*r_cyl),0,0,0;1/r_cyl,0,1,0,0,0,0;0,0,0,0,0,1/(ABD_cyl_48(4,4)*r_cyl),0;0 , 0 , 0 , 0 , 1/r_cyl ,0,0;0 ,
 ABD_cyl_48(2,2)/r_cyl - ABD_cyl_48(1,2)*ABD_cyl_48(2,1)/(ABD_cyl_48(1,1)*r_cyl), 0,- (1/r_cyl) +
 ABD_cyl_48(2,1)/(ABD_cyl_48(1,1)*r_cyl),0,0,0.36;0 , 0, 0, 0, -1, 0 ,0;0,0,0,0,0,0,0];

[Robert Mende]

So your error appears within a part of the code that you commented out. Do you still need this part?