Euler-Bernoulli Point Load Problem

I have been struggling to model an Euler-Bernoulli beam with a sinusoidal point load. This is in fact a question in the Rao Mechanical Vibrations textbook Example 8.8. I believe the issue is surrounding the load, as the modeshapes seem correct, but when the force acts the deflection is very suprising. I have uploaded the question and solution I am following from the text book and bellow is the code I am running.

%Euler-Bernoulli Fixed-Pinned Beam
clc
clear all
close all
% syms B a1 a2 a3 a4;

% Material Properties of Structural Steel
p = 8050; % Density [kg/m^3]
E = 200*10^9; % Young's Modulus [N/m^2]

% Dimensions
l = 100; % length [m]
w = 0.5; % width [m]
h = 0.5; % height [m]

% Structural properties
A = w*h; % Area [m^2]
I = (w*h^3)/12; % Second moment of area [m^4]

z = [0:100]; % Points along the beam
% t = linspace(0,10); % Time under displacement

P_a = 10000; % Magnitude of the point load [N]

a = 3; % Location of point load [m]
W = 15; % Frequency of vibration [rad/sec]

for r=1:5 % loop for each modeshape
    
    Wn_r = (r*pi/l)*(E*I/p*A)^0.5; % Natural frequency of each modeshape
    test = (1/(Wn_r^2-W^2));
    
    for x=0:100 % Position on the beam
        
        mshape_a = sin((r*pi*a)/l);

        M_shape = test*sin((r*pi*x)/l)*mshape_a; % Modeshape function

        vec(:,x+1) = M_shape;
        
    end
    
    figure(1)
    subplot(1,5,r)
    plot(z,vec)

    mat(r,:) = vec; %Stores modeshapes in matrix
end

totm = sum(mat) %sum of modeshapes

figure(2)
plot(z,totm)

for t=0:100
    
    forcefunction = sin(W*t)*P_a; % Sinusoidal point load
    
    w_x_t = ((2)/(p*A*l))*totm*forcefunction;

    test2(t+1,:) = w_x_t;
    
    figure(3)
    plot(z,w_x_t)
    
title('Time')
xlabel('Position [m]')
ylabel('Displacement [m]')
pause(0.05)

end

[darova]

Maybe the problem is in scale? Also argument of sin() changes rapidly because of t

Try:

forcefunction = sin(W*t/50)*P_a; % Sinusoidal point load
%
%
figure(3)
plot(z,w_x_t*1E4)                % scaling deformation 10 000 times
axis equal