Ultrasonic stress waves, generated during the dynamic impact on structures, were studied. A benchmark for the finite element analysis (FEA) was made to define the optimum geometrical factors, which were represented as, mesh distribution, analysis time, ultrasonic wave properties, element type, and shape to capture the dynamic phenomena compared to the theoretical exact solution. Comparison of three different dimensional finite element models was performed depending on the applied impact forces, the element size, and the structural geometry. A dynamic equivalence for these three different variables was established and found to be of a direct multiplication relation to the solid's density with the Young's modulus. The results demonstrated that the stresses in x, and y-directions, predicted by FEA simulations, matching well for the different materials under normalized time.