Page 109 - Singiresu S. Rao-Mechanical Vibrations in SI Units, Global Edition-Pearson (2017)

106 Chapter 1 Fundamentals oF Vibration
x(t) A*t/tau One term Two terms
1 1.5 1

0.8 0.8
1
0.6 0.6
x(t) 0.5
0.4 0.4
0
0.2 0.2
0 0.5 0
0 1 2 0 1 2 0 1 2
t t t
Three terms Four terms
1 1

0.8 0.8
0.6 0.6
x(t)
0.4 0.4
0.2 0.2

0 0
0 1 2 0 1 2
t t
Equations (E.1) and (E.2) with different numbers of terms.

Solution: A MATLAB program is written to plot Eqs. (E.1) and (E.2) with different numbers of
terms as shown below.

%ex1_21.m
%plot the function x(t) = A * t / tau
A = 1;
w = pi;
tau = 2;
for i = 1: 101
t(i) = tau * (i-1)/100;
x(i) = A * t(i) / tau;
end
subplot(231);
plot(t,x);
ylabel('x(t)');
xlabel('t');
title('x(t) = A*t/tau');
for i = 1: 101
x1(i) = A / 2;
end
subplot(232);
plot(t,x1);
xlabel('t');
title('One term');