The electrification of drive trains in current and next generation vehicles require vibration dampers that possess different dynamic properties than its internal combustion engine counterparts. This makes research in automotive vibration damping a hot topic. Research in this field often contains the practice of Frequency Based Substructuring (FBS) in which dynamics of individual components can be used to predict dynamics of an assembly or vice versa. A method to incorporate vibration dampers in FBS is the practice of Full Decoupling but this can be a time consuming and cumbersome exercise so the alternative method of Inverse Substructuring was developed. This approach is quicker and simpler but suffers from shortcomings as underestimating stiffness and neglecting some DoF relations. In this thesis an improvement on this technique is proposed by making use of the geometrical shape of the vibration isolator. This results in better prediction of the dynamics of the vibration isolator in most directions however the dynamicist should make a decision if this simpler method of Improved Inverse Substructuring is more suitable for the application over Full Decoupling.

As a reaction to urban densication, light weight building is an attractive concept for optimally utilizing the capacity of the existing built environment. A common issue paired with light weight construction is the need to engage in vibrational design, in order to minimize hindrance due to human activities such as walking, that cause vibrations in buildings. The Finite Element Method (FEM) is a crucial tool for accurately predicting structural behaviour in such a context. The typical problem with FEM considering large, complex or detailed structures, is that analyses may demand intolerably large computational eort to perform design studies. As a solution, a component-wise approach called Component Mode Synthesis (CMS) is proposed. CMS technique involves separating a construction into substructures, after which Model Order Reduction (MOR) is performed on each substructure individually. With this, the substructures are eciently described by a limited amount of Degrees of Freedom (DoF), after which they are assembled by means of Dynamic Substructuring (DS) techniques. Considering the large amounts of substructure DoF to be coupled to other assembly parts (typically containing 1%-10% of the total amount), an additional measure is required for analyses to be viable: a reliable interface reduction should be performed to deal with the number of unreduced interface DoF that still exist. This research investigates interface reduction by means of Orthogonal Polynomial Series, creating an a priori determined, generic reduction basis which closely resembles the true vibration modes along substructure interfaces. Its performance is investigated with several conceptual case studies, conducting reduced order analysis in Matlab and comparing the results with a full order solution. Alterations are explored, including dierent polynomial bases (Legendre and Fourier), exible couplings and viscoelasticity at either coupled substructure boundaries or bodies. The relevance of complex modes in viscoelastic structures with lightly varying damping and stiness is examined, as well as accuracy of approximations of complex modes, with the prospect of enabling arbitrary frequency dependent material properties to be represented in an ecient manner. This involves approximation of complex modes, obtained by superposition of undamped modes, for which a strategy is developed to optimize considered inclusion of undamped modes. Ultimately, a representative building is modelled in order to relate test results of OPS interface reduction to an applicable context, and to prove the overall eectiveness of the enhanced CMS strategy for large light weight building models. OPS interface reduction using Legendre series has shown to be a reliable and ecient technique depending on the frequency range considered. Its general error trends are mostly insignicant or manageable and exible/ viscoelastic boundary couplings do not de ate this. Disproportional viscoelasticity in substructure bodies, with respect to their mass and stiness matrices, are not necessarily beneted by the use of complex vibration modes when its dynamic modulus varies lightly over frequency. Though the potential which is beyond this scope, yet remains undetermined, the presented approximation technique for complex modes also comes with additional limitations besides the amount of damping. With regards to the applicative value of CMS, the analyses of the light weight building model prove that OPS interface reduction enables signicant improvement of computational eciency, yet yielding accurate results, as a valuable solution for modern-day problems.

An Oldham coupling is a constant velocity rotational transmission between two misaligned but parallel axis. Conventionally, this coupling uses two sliding contact prismatic joints, in which friction, wear, backlash and lubrication is unavoidable. Conversion to a compliant mechanism, in which motion is accomplished by elastic deformation instead, would eliminate all these drawbacks. Within PME, such a coupling is designed already. However, it was observed that it does not perform well for higher velocities and accelerations. Furthermore, it was indicated that little research is available about the dynamic behaviour of compliant mechanisms at all.
In this thesis, the dynamic performance of the family of compliant Oldham couplings is analysed and predicted. A straightforward generic analysis method is proposed, based on multibody dynamics. A case study is performed on the existing compliant design to validate the proposed modelling techniques. Its dynamic performance is evaluated experimentally and its failure mechanisms are indicated. Based on the gained knowledge, design improvements are proposed. Finally, this work now facilitates the design and implementation of compliant Oldham couplings in dynamic applications.