What is wrong in line 101?

Calculate internal stresses for maximum and minimum bending moments and plot their distribution on the cross section.

%%Q1f
clc; clear; close all
disp('Simply Supported Beam'); 

% Data input section 
disp(' ');
L    = input('Length of beam in meter =  '); 
disp(' ');disp('Type 1 for point load, Type 2 for udl')
Type = input('Load case = '); 

if Type == 1
    disp(' ');
    W = input('Load applied in kN = ');
    disp(' ');
    a = input('Location of Load from left end of the beam in meter = ');
    c  = L-a;
    
    R1 = W*(L-a)/L;             % Left Support Reaction. 
    R2 = W*a/L;                 % Right Support Reaction.
    
else
    disp(' ');
    W  = input('Uniformly distributed load in kN/m = ');
    disp(' ');
    b  = input('Length of udl in meter = ');
    disp(' ');
    cg = input('C.G of udl from left end of the beam in meter = ');
    a  = (cg-b/2);
    c  = L-a-b;
    
    R1 = W*b*(b+2*c)/(2*L); % Left Support Reaction. 
    R2 = W*b*(b+2*a)/(2*L);                 % Right Support Reaction.
end

% Discretization of x axis.
n = 1000;                   % Number of discretization of x axis.
delta_x = L/n;              % Increment for discretization of x axis.
x = (0:delta_x:L)';         % Generate column array for x-axis.  

V = zeros(size(x, 1), 1);   % Shear force function of x. 
M = zeros(size(x, 1), 1);   % Bending moment function of x. 


% Data processing section
if Type == 1
    for ii = 1:n+1
        % First portion of the beam, 0 < x < b
        V(ii) = R1;
        M(ii) = R1*x(ii);
        
        % Second portion of the beam, b < x < L
        if x(ii) >= a
            V(ii) = R1-W;
            M(ii) = R1*x(ii)-W*(x(ii)-a);
        end
    end
    x1   = a;
    Mmax = W*a*(L-a)/L;
else
    for ii = 1:n+1
        % First portion of the beam, 0 < x < a
        if x(ii) < a
            V(ii) = R1;
            M(ii) = R1*x(ii);
        elseif a <= x(ii) && x(ii)< a+b
            % Second portion of the beam, a < x < a+b
            V(ii) = R1-W*(x(ii)-a);
            M(ii) = R1*x(ii)-W*((x(ii)-a)^2)/2;
        elseif x(ii) >= (a+b)
            % Second portion of the beam, a+b < x < L
            V(ii) = -R2;
            M(ii) = R2*(L-x(ii));
        end
    end 
    x1 = a+b*(b+2*c)/(2*L);
    Mmax = W*b*(b+2*c)*(4*a*L+2*b*c+b^2)/(8*L^2);
end

disp(' ');disp (['Left support Reaction'  '  = ' num2str(R1) ' ' 'kN'])
disp(' ');disp (['Left support Reaction'  '  = ' num2str(R2) ' ' 'kN'])
disp(' ');disp (['Maximum bending moment'  ' = ' num2str(Mmax) ' ' 'kNm'])

figure
subplot(2,1,1);
plot(x, V, 'r','linewidth',1.5);
grid
line([x(1) x(end)],[0 0],'Color','k');
line([0 0],[0 V(1)],'Color','r','linewidth',1.5);
line([x(end) x(end)],[0 V(end)],'Color','r','linewidth',1.5);
title('Shear Force Diagram','fontsize',16)
text(a/2,V(1),num2str(V(1)),'HorizontalAlignment','center','FontWeight','bold','fontsize',16)
text((L-c/2),V(end),num2str(V(end)),'HorizontalAlignment','center','FontWeight','bold','fontsize',16)
axis off

subplot(2,1,2);
plot(x, M, 'r','linewidth',1.5);
grid
line([x(1) x(end)],[0 0],'Color','k');
line([x1 x1],[0 Mmax],'LineStyle','--','Color','b');
title('Bending Moment Diagram','fontsize',16)
text(x1+1/L,Mmax/2,num2str(roundn(Mmax,-2)),'HorizontalAlignment','center','FontWeight','bold','fontsize',16)
text(x1,0,[num2str(roundn(x1,-2)) ' m'],'HorizontalAlignment','center','FontWeight','bold','fontsize',16)
axis off

[Ankit]

what error you are getting? it is working without any error for me.

[Rik]

Have a read here and here. It will greatly improve your chances of getting an answer.

You're making it difficult for people to help you. We can't run your code, because we're missing plausible values to enter. We also don't know which line should be resulting in an error. We don't know which lines are essential for you, or which lines may be removed for testing.

1. Cut down your code to the smallest unit that will trigger the error
2. Describe what behavior you wanted/expected instead

The best way is to make sure you can use the 'run code' tool. That way we don't have to guess the location of the error and you can make sure all data is there to ensure the error can be reproduced.

You might also want to accept an answer if it helped solve your issue. Did you get a solution here or here?

[MR JUSTIN ACHARJEE Sumanta]

text(x1+1/L,Mmax/2,num2str(roundn(Mmax,-2)),'HorizontalAlignment','center','FontWeight','bold','fontsize',16)

I am having error in this line.

[Steven Lord]

Please show us the the full and exact text of the error and/or warning messages (all the text displayed in red and/or orange in the Command Window when you run your code.)

Answer 1

[Yongjian Feng]

Your file has no line 101. Only 94 lines in total.

Tried some sample input data, and it works without error. What inputs are needed to reproduce the error?

[MR JUSTIN ACHARJEE Sumanta]

text(x1+1/L,Mmax/2,num2str(roundn(Mmax,-2)),'HorizontalAlignment','center','FontWeight','bold','fontsize',16)

This line is showing error.

[Yongjian Feng]

It must be related to the inputs you gave. Tried some random inputs and it works.

1. Give us the inputs you use to reproduce the error.
2. Paste the error here.