Four methods of interval finite element for static analysis are proposed.
Using the second-order and third-order Taylor expansion , interval finite element for
static analysis is addressed. Neumann expansion of interval finite element for static
analysis is formulated. Interval finite element using Sherman -Morrison-Woodbury
expansion is presented. A new iterative method (NIM) is used for interval finite
element calculation. Four methods can calculate the upper and lower bounds of node
displacement and element stress.