MATLAB Answers

Range of matrices?

조회 수: 1(최근 30일)
Steven P.
Steven P. 2021년 5월 2일
댓글: Steven Lord 2021년 5월 2일
I am having trouble with getting a range of Qbar matrix values for my different orientation angles below. I input the number of plies (n) and the orientation for each ply (theta). Now, I am trying to calculate a Qbar matrix for each ply based on its orientation but I keep getting an error. So i defined k=1:n and that u=theta(k)*pi/180 to convert it to radians. I do not know if I am even applying the orientation angle right for each ply. Does anyone know what I am doing wrong?
Thank you.
% Number of plies and orientation of each ply
prompt2 = {'Number of plies'};
dlgtitle2 = 'Number of plies definition';
dims2 = [1 100];
definput2 = {'4'}; % Default input
answer2 = inputdlg(prompt2,dlgtitle2,dims2,definput2);
n = str2num(answer2{1});
theta = zeros(1,n);
for i = 1:length(theta)
prompt3 = {sprintf('Enter orientation angle (in degrees) for ply #%d',i)};
dlgtitle3 = 'Laminate stacking sequence definition';
dims3 = [1 100];
definput3 = {'0'}; % Default input
answer3 = inputdlg(prompt3,dlgtitle3,dims3,definput3);
theta(i) = str2num(answer3{1});
end
%
% define an array h that stores the location of ply interfaces here ...
% the array should be the length of the theta array plus one (i.e., there
% are n+1 interfaces for a n ply laminate)
% be careful to take account of the cases of even and odd number of plies
% when there are an odd number of plies, interfaces are located at 1.5t, 2.5t, etc.
%%
% Compute Qbar for each ply
for k=1:n
u = theta(k)*pi/180;
c = cos(u);
s = sin(u);
Tsigma(k)= [c^2 s^2 2*c*s;...
s^2 c^2 -2*c*s;...
-c*s c*s c^2-s^2];
Tepsilon(k)= [c^2 s^2 c*s;...
s^2 c^2 -c*s;...
-2*c*s 2*c*s c^2-s^2]
Teps = inv(Tepsilon)
Sbar(k) = Teps*S*Tsigma
Qbar(k) = inv(Sbar);
end

채택된 답변

Steven Lord
Steven Lord 2021년 5월 2일
Tsigma(k)= [c^2 s^2 2*c*s;...
s^2 c^2 -2*c*s;...
-c*s c*s c^2-s^2];
What's on the right side of the equals sign is probably a 3-by-3 matrix since c and s are likely 1-by-1 matrices.
What's on the left side of the equals sign is a 1-by-1 matrix.
If you were buying groceries, how would you stuff 9 eggs into 1 cup of an egg carton without scrambling them? You wouldn't. MATLAB doesn't know how to stuff 9 elements into 1 element of a matrix either.
If you need to store the matrices for later use, store them in a cell array. If you don't, eliminate the (k) part of the left side of the equals sign.
  댓글 수: 2
Steven Lord
Steven Lord 2021년 5월 2일
Search the documentation for "cell array".

댓글을 달려면 로그인하십시오.

추가 답변(0개)

태그

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by