# Overshoot of 15% what is damping ratio

1. Sep 28, 2014

### Dustinsfl

1. The problem statement, all variables and given/known data
A shock absorber is to be designed to limit its overshoot to $15$ percent of its initial displacement when released. Find the damping ratio $\zeta_0$ required.

2. Relevant equations

3. The attempt at a solution

My question is since log decrement, $\delta = \ln\frac{x_1}{x_2} = \frac{2\pi\zeta}{\sqrt{1 - \zeta^2}}$, for a 15% overshoot, do I set $\frac{x_1}{x_2} = 1.15$ and then solve for $\zeta$?

2. Sep 28, 2014

### Staff: Mentor

How is overshoot defined? In the way you use it it looks odd (1000% overshoot would mean a strong damping then).
Also make sure you use the correct amplitudes to compare - after 1/2 of the oscillation or a full oscillation?

3. Sep 28, 2014

yes