计算含有偏微分的二重积分积不出来答案是为什么，百度也没找到解决办法，求大佬帮忙看看！

Question

acxataw 2023-5-22

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1969789-

回答： cpxnwm 2023-5-22

b=0.0175;h=0.114;h0=0.01;N=4;r0=0.0325;d1=(h-(N+1)*h0)/N;

syms x y n;

U=x*y+symsum(32*b^2*(-1)^((n+1)/2)*sin(n*pi*x/(2*b))*sinh(n*pi*y/(2*b))/(n^3*pi^3*cosh(n*pi*d1*sqrt(d1^2+pi*(2*(r0+b)+b)^2)/(2*b))),n,1,inf);

A=int(int(x^2+y^2+x*diff(U,y)-y*diff(U,x),x,0,sqrt(d1^2+pi*(2*(r0+b)+b)^2)),y,-h0/2,h0/2);

A=vpa(A,10)

结果是：

A =

numeric::int(numeric::int(x^2 + y^2 + x*(x + (1724034232352768*symsum(((-1)^(n/2 + 1/2)*((exp(-(n*x*pi*200i)/7)*1i)/2 - (exp((n*x*pi*200i)/7)*1i)/2)*((100*n*pi*exp(-(200*n*y*pi)/7))/7 + (100*n*pi*exp((200*n*y*pi)/7))/7))/(n^3*(exp(-(7525588108204847*n*pi)/78812993478983680)/2 + exp((7525588108204847*n*pi)/78812993478983680)/2)), n, 1, Inf))/5454681879044716875) - y*(y - (1724034232352768*symsum(((-1)^(n/2 + 1/2)*(exp(-(200*n*y*pi)/7)/2 - exp((200*n*y*pi)/7)/2)*((100*n*pi*exp(-(n*x*pi*200i)/7))/7 + (100*n*pi*exp((n*x*pi*200i)/7))/7))/(n^3*(exp(-(7525588108204847*n*pi)/78812993478983680)/2 + exp((7525588108204847*n*pi)/78812993478983680)/2)), n, 1, Inf))/5454681879044716875), x == 0..7525588108204847/36028797018963968), y == -1/200..1/200)

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