help with plotting function of time

random1072

2020 4 29

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EXAM2_2.mlx

" Plot on the same graph the motion of x4(t) in the original domain as well as the eigenspace {x4}B (t)." Really confused on how to even do this. Please help. Shown is my code.

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Geoff Hayes 2020-4-29

Please include (via attachment or by copying and pasting) your code to this question rather than including screen shots of the code.

random1072 2020-4-29

编辑：Geoff Hayes 2020-4-29

在 MATLAB Online 中打开

M = [11 0 0 0 0 0 0;
     0 18 0 0 0 0 0;
     0 0 17 0 0 0 0;
     0 0 0 17 0 0 0;
     0 0 0 0 13 0 0;
     0 0 0 0 0 10 0;
     0 0 0 0 0 0 12]
 
K = 108; % altering stiffness so system will become stable
% K value that makes system stable = 108 N/M
% initialize the end masses as pushing outward (i.e. x1 @ t=0 = −1 unit and x7 @ t=0 = +1 unit) and track 
% the behavior of the middle mass x4 as a function of increasing time
 
K_Matrix_New = [(-K-K) K 0 0 0 0 0; % new K matrix where x1 and x7 are pushed out
            K (-K-K) K 0 0 0 0;
            0 K (-K-K) K 0 0 0;
            0 0 -K 0 K 0 0;
            0 0 0 -K (K+K) -K 0;
            0 0 0 0 -K (K+K) -K;
            0 0 0 0 0 -K (K+K) ]
        
K_tilde_New = M^(-1/2)*K_Matrix_New*M^(-1/2)
e = eig(K_tilde_New) % gives my eigenvalues where none are imaginary
w_new = sqrt(e) % gives the value of the frequencies +/-