我试着取（从x到B/2的积分pz（zeta）d（zeta）），这是升力产生的剪力，和-（从x到b/2的积分（zeta-x）*pz（zeta）d（zeta）），这是升力产生的力矩

% Create a spanwise distance vector
x = linspace(0, b/2, 100);
% Calculate lift distribution pz(x)
pz = p0 * sqrt(1 - (x / (b/2)).^2);
% Preallocate arrays for shear force and moment distributions
Vz_lift = zeros(size(x));
My_lift = zeros(size(x));
% Calculate shear force and moment distributions
for i = 1:length(x)
    Vz_lift(i) = trapz(x(i:end), pz(i:end), 2);
    My_lift(i) = -trapz(x(i:end), (x(i:end) - x(i)) .* pz(i:end),2);
end`
% Plot shear force distribution
subplot(3,1,2)
plot(x, Vz_lift);
xlabel('Spanwise Distance (x)');
ylabel('Shear Force Distribution (N)');
title('Shear Force Distribution due to Lift over Half Span');
% Plot moment distribution
subplot(3,1,3)
plot(x, My_lift);
xlabel('Spanwise Distance (x)');
ylabel('Moment Distribution (N*m)');
title('Moment Distribution due to Lift over Half Span');

由此产生的力矩和剪力图在我看来不对。我做的积分对吗？