Polynomial chaos can also be used to represent random functions, but for that purpose something called a Karhunen-Lòeve expansion is also needed.
Elsewhere in FEAsphere: failure modes, and how and why they are indeed uncertain. Plus stochastics in buckling, and some collaboration in the making.
For analysing uncertain systems, something called polynomial chaos can be used. Despite the horrible name, it is actually quite simple. Read to learn!