Hi Rajni
I understand that you would like to implement the moving load using the Heaviside function in your differential equation.
Ensure the function name inside the ode45 call matches the actual function definition. In your original code, you called Lin inside ode45, but your function was defined as Linear12. I have corrected this to use Linear12 in both places. Your usage of the Heaviside function to model the moving load in in the correct direction. The expression heaviside(L/V - t) effectively turns on the force as the load starts affecting the system, based on the velocity of the load and the length of the system it's moving over.
Here it the code for your reference:
clc;
clear all;
% Time span
tspan = [0:0.1:10];
y0 = [0; 0];
% Parameters
F0 = 9.8; % Magnitude of moving load
L = 4; % Length
V = 0.1; % Velocity
m = 28.152;
C = 500;
% Solve the ODE
[t,y] = ode45(@(t,y) Linear12(t,y,C,F0,m,L,V), tspan, y0);
% Plot the solution
plot(t, y(:,1));
xlabel('Time');
ylabel('Displacement');
title('Displacement over Time');
function [f] = Linear12(t,y,C,F0,m,L,V)
% Moving load
p1 = F0 * sqrt(2/(m*L)) * sin((pi*V*t)/L) .* heaviside(L/V - t);
% Initialize the derivative vector
f = zeros(2,1);
% Differential equations for the system
f(1) = y(2);
f(2) = -50^2 * y(1) - C * y(2) + p1;
end
Hope it helps!
