# Multiple Preloads

The following equations show the method for computing the bushing output for multiple preloads.

Let:

`n`be the number of preloads in the test data; $i$ be the current load case.- Sort the preloads ${P}_{i}$ and renumber the preloads such that ${P}_{1}<{P}_{2}<\mathrm{...}<{P}_{n}$ .
- ${x}_{i}$ be the filter output corresponding to the ${i}^{th}$ load case.
- $F{0}_{i}$ be the static response of the bushing corresponding to the ${i}^{th}$ load case.
- ${f}_{i}$ be the dynamic response corresponding to the ${i}^{th}$ load case.

Then for each preload, ${P}_{i}$ , defines weights ${W}_{i}$ :

And the total force is calculated as:

as you see detailed in the following figure: