With this expression by Dan Ebberts, you can loop a shake animation for a given duration.

freq = 1; // Frequency
amp = 110; // Amplitude
loopTime = 3; // Cycle time (in seconds)
t = time % loopTime;
wiggle1 = wiggle(freq, amp, 1, 0.5, t);
wiggle2 = wiggle(freq, amp, 1, 0.5, t - loopTime);
linear(t, 0, loopTime, wiggle1, wiggle2)