Why am I receiving this error?
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
% Input data
EL = 38.60e9; % Longitudinal modulus (Pa)
ET = 8.27e9; % Transverse modulus (Pa)
GLT = 4.14e9; % Shear modulus (Pa)
nuLT = 0.26; % Poisson's ratio
thickness = 0.002; % Thickness of each layer (m)
layer_angles = [45, -45, -45, 45]; % Fiber orientations of each layer (degrees)
mid_plane_strains = [0.05, 0.00, 0.00]; % Mid-plane strains (epsilon_x, epsilon_y, gamma_xy)
curvatures = [0.05, 0.020, 0.0250; 0, 0.010, 0.0125]; % Curvatures (kappa_x, kappa_y, kappa_xy)
% Number of layers
num_layers = length(layer_angles);
% Initialize arrays to store stresses
sigma_x_top = zeros(num_layers, 1);
sigma_y_top = zeros(num_layers, 1);
tau_xy_top = zeros(num_layers, 1);
sigma_x_bottom = zeros(num_layers, 1);
sigma_y_bottom = zeros(num_layers, 1);
tau_xy_bottom = zeros(num_layers, 1);
% Compute stresses for each layer
for i = 1:num_layers
theta = deg2rad(layer_angles(i));
% Transformation matrix
T = [cos(theta)^2, sin(theta)^2, 2*sin(theta)*cos(theta);
sin(theta)^2, cos(theta)^2, -2*sin(theta)*cos(theta);
-sin(theta)*cos(theta), sin(theta)*cos(theta), cos(theta)^2-sin(theta)^2];
% Reduced stiffness matrix
Q11 = EL / (1 - nuLT^2);
Q12 = nuLT * EL / (1 - nuLT^2);
Q22 = ET / (1 - nuLT^2);
Q66 = GLT;
Q = [Q11, Q12, 0;
Q12, Q22, 0;
0, 0, Q66];
% Transform stiffness matrix to layer coordinates
Q_bar = (T) / Q * T';
% Strain matrix
strain = [mid_plane_strains(1); mid_plane_strains(2); mid_plane_strains(3)];
curvature = [curvatures(1, i); curvatures(2, i); 0]; % Assume no curvature in z direction
% Stress resultants
stress_resultants = Q_bar * strain + curvature;
% Stresses at top and bottom of the layer
sigma_x_top(i) = stress_resultants(1) + mid_plane_strains(1) * thickness / 2;
sigma_y_top(i) = stress_resultants(2) + mid_plane_strains(2) * thickness / 2;
tau_xy_top(i) = stress_resultants(3);
sigma_x_bottom(i) = stress_resultants(1) - mid_plane_strains(1) * thickness / 2;
sigma_y_bottom(i) = stress_resultants(2) - mid_plane_strains(2) * thickness / 2;
tau_xy_bottom(i) = stress_resultants(3);
end
% Display results
fprintf('Layer\tSigma_x_top (Pa)\tSigma_y_top (Pa)\tTau_xy_top (Pa)\tSigma_x_bottom (Pa)\tSigma_y_bottom (Pa)\tTau_xy_bottom (Pa)\n');
for i = 1:num_layers
fprintf('%d\t%.2f\t%.2f\t%.2f\t%.2f\t%.2f\t%.2f\n', i, sigma_x_top(i), sigma_y_top(i), tau_xy_top(i), sigma_x_bottom(i), sigma_y_bottom(i), tau_xy_bottom(i));
end
% Plot stress variation through thickness
layer_depths = linspace(-thickness/2, thickness/2, num_layers);
figure;
hold on;
plot(sigma_x_top, layer_depths, 'r', 'LineWidth', 1.5);
plot(sigma_y_top, layer_depths, 'g', 'LineWidth', 1.5);
plot(tau_xy_top, layer_depths, 'b', 'LineWidth', 1.5);
plot(sigma_x_bottom, layer_depths, 'r--', 'LineWidth', 1.5);
plot(sigma_y_bottom, layer_depths, 'g--', 'LineWidth', 1.5);
plot(tau_xy_bottom, layer_depths, 'b--', 'LineWidth', 1.5);
title('Stress Variation Through Laminate Thickness');
xlabel('Stress (Pa)');
ylabel('Depth (m)');
legend('\sigma_x', '\sigma_y', '\tau_{xy}', 'Location', 'best');
grid on;
hold off;
ERROR:
Index in position 2 exceeds array bounds. Index must not exceed 3.
Error in Project_1_new (line 45)
curvature = [curvatures(1, i); curvatures(2, i); 0]; % Assume no curvature in z direction
0 commentaires
Réponses (2)
Alan Stevens
le 19 Avr 2024
You have 4 layers
layer_angles = [45, -45, -45, 45];
but data for only three
mid_plane_strains = [0.05, 0.00, 0.00]; % Mid-plane strains (epsilon_x, epsilon_y, gamma_xy)
curvatures = [0.05, 0.020, 0.0250; 0, 0.010, 0.0125]; % Curvatures (kappa_x, kappa_y, kappa_xy)
0 commentaires
Voss
le 19 Avr 2024
curvatures is of size 2-by-3:
curvatures = [0.05, 0.020, 0.0250; 0, 0.010, 0.0125] % Curvatures (kappa_x, kappa_y, kappa_xy)
layer_angles is of size 1-by-4:
layer_angles = [45, -45, -45, 45] % Fiber orientations of each layer (degrees)
The loop iterates from i = 1 to i = 4:
num_layers = length(layer_angles);
% ...
for i = 1:num_layers
Therefore, on the 4th iteration, when this line tries to access elements from column 4 of curvatures:
curvature = [curvatures(1, i); curvatures(2, i); 0]; % Assume no curvature in z direction
the error is thrown because curvatures only has 3 columns.
0 commentaires
Voir également
Catégories
En savoir plus sur Stress and Strain dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!