Interval variables have an effect on linear vibration. The linear vibration is
transformed into a static problem by Newmark method. The perturbation method,
Neumann expansion method, Taylor expansion method, Sherman Morrison
Woodbury expansion method and a new iterative method of interval finite element
for linear vibration are proposed. The detailed derivation processes are explored.
Keywords: Linear vibration, Perturbation, Neumann expansion, Taylor expansion, Sherman Morrison Woodbury expansion, A new iterative method.