In this paper, we use the Variational Iteration Method (VIM) to find the approximate analytical solution for an initial value problem involving the fuzzy Duffing ordinary differential equation. VIM allows for the solution of the differential equation to be calculated in the form of an infinite series in which the components can be easily computed. Numerical examples were solved to illustrate the capability of VIM in this regard.
Definition 2.4. A mappingfor some interval is called a fuzzy function process [14] and we denote the r-level set by:The r-level sets of a fuzzy number are much more effective as representation forms of fuzzy set. Fuzzy sets can be defined by the families of their r-level sets based on the resolution, identity theorem [12,33].Definition 2.5. The fuzzy integral of fuzzy process [31], ̃( ) ∫ ̃( ) for and ,is defined by:of 14 4 Journal of Interpolation and Approximation in Scientific Computing