What is wrong with my code

Question

Daniel Sode 2020-7-20

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/567927-what-is-wrong-with-my-code

回答： Dinesh Yadav 2020-7-23

N = 16;
E = 200e9; % Young Modulus (Pa)
b = 0.1; % Top width (m^2)
a = 0.025; % Bottom width (m^2)
L = 1.0; % Length (m)
rho = 77e3; % Force density (N/m^3)
Le = L./N;
ff = 0;
for i = 1:N
    w(i)=(((i-0.5).*Le)*((b-a)./L))+a;  %Calculates avg width (m)
    A(i)=w(i).^2;                       %Calculates element area (m^2)
    k(i) = A(i)*E/Le;                   %Local Stiffness Matrix constact
    f(i) = ff*A(i)*le*rho/2;            %Local Force Matrix constant
end  
KG = zeros(N+1,N+1)
FG = zeros(N+1,N+1)
for ii = 1:N
    KG(ii:ii+1,ii:ii+1)=KG(ii:ii+1)+k(i);
    FG(ii:ii+1,ii:ii+1)=FG(ii:ii+1)+f(i);
end
Displacement = inv(KG)*FG;
plot(N,Displacement,'b');
hold on
plot(N,Displacement,'*','color','r')
ylabel('end deflection in mm');
xlabel('no of element')
    

5 个评论
显示 3更早的评论隐藏 3更早的评论

Daniel Sode 2020-7-20

I redid the code and am getiing this error

Unable to perform assignment because the left and right sides have a different number of elements.

Error in Termproject (line 10)

w(i)=(((i-0.5).*Le)*((b-a)./L))+a; %Calculates avg width (m)

Daniel Sode 2020-7-20

在 MATLAB Online 中打开

N  = linspace(1,16,100);
E = 200e9; % Young Modulus (Pa)
b = 0.1; % Top width (m^2)
a = 0.025; % Bottom width (m^2)
L = 1.0; % Length (m)
rho = 77e3; % Force density (N/m^3)
Le = L./N;
ff = 0;
for i = 1:N
    w(i)=(((i-0.5).*Le)*((b-a)./L))+a;  %Calculates avg width (m)
    A(i)=w(i).^2;                       %Calculates element area (m^2)
    k(i) = (A(i)*E/Le);%*[1 -1;-1 1];       %Local Stiffness Matrix constact
    f(i) = (ff*A(i)*Le*rho/2);%*[1;1];      %Local Force Matrix constant
end  
KG = zeros(N+1,N+1);
FG = zeros(N+1,N+1);
for i = 1:N
    KG(i,i) = KG(i,i) + k(i);
    KG(i,i+1) = KG(i,i+1) - k(i);
    KG(i+1,i) = KG(i+1,i) - k(i);
    KG(i+1,i+1) = KG(i+1,i+1) + k(i);
    FG(i,1) = FG(i,1) + f(i);
    FG(i+1,1) = FG(i+1,1) +f(i)
end
Displacement = inv(KG)*FG;
plot(N,Displacement,'b');
hold on
plot(N,Displacement,'*','color','r')
ylabel('end deflection in mm');
xlabel('no of element')
    

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Dinesh Yadav 2020-7-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/567927-what-is-wrong-with-my-code#answer_469638

在 MATLAB Online 中打开

Change to the following code

len = length(N)              %N is 1x100 you want i to go from 1 to 100 therefore change to length(N) instean of N
for i = 1:len
    w(i)=(((i-0.5)*Le(i))*((b-a)/L))+a;  % Le is also 1x100 you want to take one elsment at a time use Le(i)
    A(i)=w(i).^2;                       %
    k(i) = (A(i)*E/Le(i));%*[1 -1;-1 1];       %
    f(i) = (ff*A(i)*Le(i)*rho/2);%*[1;1];      %
end  
KG = zeros(len+1,len+1);
FG = zeros(len+1,len+1);
for i = 1:len