Frequency Response Analysis is used to calculate the response of a structure subject to steady state oscillatory excitation. Typical applications are NVH (Noise, Vibration and Harshness) analyses of vehicles, rotating machinery and transmissions. The analysis is to compute the response of the structure, which is actually transient, in a static frequency domain. The loading is sinusoidal. The loads can be forces, displacements, velocity and acceleration. The response occurs at the same frequency and damping would lead to a phase shift. The outputs from a frequency response analysis are displacements, velocities, accelerations, forces, stresses and strains. The responses are usually complex numbers that are either given as magnitude and phase angle or as real and imaginary part.