Xi Engineering Consultants use numerical simulation to help design machinery, improve its performance and assess static and fatigue failure risk. These simulations can also be used to assess the impact on human work in and around machinery, such as through noise and vibration. Xi use COMSOL Multiphysics to construct models of machines and their performance which are solved in using an eigenfrequency solve to produce Campbell diagrams in the frequency domain to determine the effect of frequency matching or in the time domain to analysis temporal loading. Commonly, a multibody dynamics approach is used to model machinery, allowing the efficient simulation of mixed systems of flexible and rigid bodies, where each body may be the subject of large rotational or translational displacements. These models can include the effects of lubrication pressures and thermal effects.