This paper proposes a new strategy based on the proper generalized decomposition method to solve the forced vibration problem in two-dimensional (2D) layered beams. The approach redefines the problem by approximating the displacement field as a sum of separated functions of x, z, and ω and proposes an iterative algorithm that solves three 1D problems at each iteration. Several numerical tests with different slenderness ratios and boundary conditions are considered to validate the method. The results in terms of modal parameters and frequency response functions are analyzed and compared with exact elasticity solution and finite element simulations with very good agreements.