% 计算每个网格点的主应力 S = [S1(:), S2(:), S3(:)]; [~, D] = eig(S); sigma1 = D(:, 3); sigma2 = D(:, 2); sigma3 = D(:, 1); % 计算每个网格点的 Mises 应力和 Tresca 应力 seq = sqrt((sigma1 - sigma2).^2 + (sigma2 - sigma3).^2 + (sigma3 - sigma1).^2) / sqrt(2); taumax = max(abs(sigma1 - sigma2), abs(sigma2 - sigma3), abs(sigma3 - sigma1)); % 绘制 Mises 应力和 Tresca 应力在 pi 平面上的投影 figure; scatter(seq, taumax, 10, 'filled'); xlabel('Equivalent Stress \sigma_{eq}'); ylabel('Maximum Shear Stress \tau_{max}'); title('Mises and Tresca in Principal Stress Space'); grid on; % 绘制主应力坐标轴 hold on; plot([0 1], [0 0], '-k', 'LineWidth', 1); plot([0 0], [0 1], '-k', 'LineWidth', 1);这段代码尤问题 改下

可能是因为代码中使用了中文注释，容易造成编码错误。同时，代码中的变量名可能也存在一些问题，建议改为英文。

以下是修改后的代码：

% Calculate the principal stresses at each grid point, S = [S1(:), S2(:), S3(:)]
[~, D] = eig(S);
sigma1 = D(:, 3);
sigma2 = D(:, 2);
sigma3 = D(:, 1);

% Calculate the Mises stress and Tresca stress at each grid point
seq = sqrt((sigma1 - sigma2).^2 + (sigma2 - sigma3).^2 + (sigma3 - sigma1).^2) / sqrt(2);
taumax = max([abs(sigma1 - sigma2), abs(sigma2 - sigma3), abs(sigma3 - sigma1)], [], 2);

% Plot the Mises stress and Tresca stress in the principal stress space
figure;
scatter(seq, taumax, 10, 'filled');
xlabel('Equivalent Stress \sigma_{eq}');
ylabel('Maximum Shear Stress \tau_{max}');
title('Mises and Tresca in Principal Stress Space');
grid on;

% Plot the principal stress coordinate axes
hold on;
plot([0 1], [0 0], '-k', 'LineWidth', 1);
plot([0 0], [0 1], '-k', 'LineWidth', 1);