Fluid Based Inerter Designs to Enhance Vibration Suppression Systems

Mitigating unwanted vibration in mechanical structures via effective and reliable approaches is an important and difficult part of the design process. For example, a good balance between ride comfort and handling for passenger vehicles, the need to build taller and more slender buildings while maintaining good dynamic performances under wind and earthquake disturbances, and the trade off between maintaining straight running stability and reducing track wear when curving for railway vehicles, have all attracted much research from both academia and industry. In the current drive for more flexible, lightweight and more efficient structures, enhancing the capability of vibration suppression systems has become even more important.

The introduction of the inerter concept has from theoretical point of view fundamentally enhanced the capability of passive vibration suppression systems. Significant theoretical performance advantages for a wide range of mechanical structures have been identified. However, when working on real applications, we face the obstacle of inadequate knowledge of the dynamic properties of physical inerter realisations. This project will establish accurate fluid based inerter models and demonstrate the potential superiority of such designs for passenger cars, tall buildings and railway vehicles through case studies developed in close collaboration with industrial project partners.

The proposed work will enable the widespread uptake of fluid inerter based vibration suppression design techniques and constitute a major step towards wide spread application in multiple industrial sectors including road and rail transportation, civil engineering as well as aerospace engineering. The resulting improvements in the UK's capability for advanced design will greatly assist the high-end manufacturing industry to maintain its competitive edge.

Short-term impacts of proposed research will be in academic areas related to vibration suppression. The innovative fluid based inerter designs and the network synthesis based design methodology will stimulate new research directions and opportunities.

Medium-term impacts will be the application of inerter combined systems in the automotive, railway and civil engineering industrial sectors. Successful applications will not only benefit the relevant manufacturers, but also contribute to reductions in consumed resources and energy as a society. For example, in the UK, road maintenance and railway infrastructure maintenance cost approximately 1.2 billion pounds and 1 billion pounds, respectively. Proposed approaches have already shown promising theoretical improvement in both areas by effectively reducing the dynamic tyre force and the wheel-rail contact force. In multi-storey building simulations, significantly improved dynamic performance under external disturbances when compared to the commonly used, but heavy, tuned-mass-damper has also been obtained. This will enable taller and more cost-effective building to be built, especially in congested urban environments (e.g. London, Tokyo, New York, etc.) where land use optimisation is essential.

Longer-term effects will be expanded applications of fluid inerters devices in a wider range of industrial sectors. For example, more effective vibration control of airplane wings can enable lighter materials and structures to be used, which will result in better energy efficiency. More road-friendly suspensions for heavy-duty vehicles can significantly reduce the cost of road maintenance in the UK and worldwide. Such step change to the UK's capability for advanced design will assist the UK high-end manufacturing industry to maintain its competitive edge in the face of increasing competition from around the world.

The industrial support for the proposed project from five partners makes the high impact of this project clear. This can also be seen from the statements in the Letters of Support from project partners: " We anticipate this project will help us in developing and designing a fluid-based inerter for automotive suspension application in the future. This will feed into our next generation of suspension with improved ride characteristics" (Jaguar Land Rover); " Through discussions, we believe the approach proposed by Dr Jiang is very promising in terms of improving rolling stock dynamic performance" (SNC-Lavalin Rail & Transit); " The designs you put forward are potentially transformative because it will allow for safer and cost-effective buildings through the enhanced performance of vibration suppression systems to control wind-induced and earthquake oscillations " (RWDI). The strong support from the UK-based damper manufactures, Camloc Motion Control and Quantum Racing Services, also provides evidence of the potential impact of this project.