In this work, we perform three-dimensional finite element simulations of a solid electrically conducting bar with pre-defined material defects moving across static magnetic field lines of a permanent magnet. This study is motivated by the novel non-destructive testing technique called Lorentz force eddy current testing (LET), which is based on the measurement of the Lorentz forces acting on the magnet. In particular, we perform parametric studies to quantify the effect of various parameters on perturbations of the Lorentz force, such as: defect depth, testing speed, electrical conductivity, and magnet position. The analyses provide reference results to understand the feasibility and testing capabilities of LET. The experimental validation of the numerical results is presented as well.