IntroductionAs we become more able to provide stronger structures with less material, a reduction in thickness to seemingly create a more optimal design for the strength limit state can lead to problems in other areas; namely the serviceability limit state for vibration. Structural vibration as a phenomenon has been studied for decades. Although much is now understood about the effects of vibration and cyclical loading, the complexity of the loading patterns and the effects of combining loading patterns have until recently prevented substantial analysis complex structures. Prior to the development of computer software, the completion of the volume of computation required for the analysis of structures subject to complex loading patterns was not practically achievable. Since the development of software, using the Finite Element Method (FEM), it has been possible to calculate the anticipated response of structures under dynamic conditions. ...........................