Efficient design of truss footbridges with stiffness-proportional inerters

Excessive vibrations in footbridges have recently received more attention from researchers and professionals. This has resulted in a surge in popularity for passive energy dissipation systems, such as tuned mass dampers, viscous dampers, and inerters. While design methods with tuned mass dampers and viscous dampers exist, the design of footbridges using inerters is still a challenge. This paper proposes a design procedure for truss-like footbridges incorporating inerters. The concept of the approach is based upon a mathematical derivation of the eigenproblem of a multi-degree-of-freedom structural system, enhanced with stiffness-proportional inertances. This outcome enables tuning the highest natural frequency of the system to a predefined value. The proposed design procedure adjusts all natural frequencies, such that the highest natural frequency of a structural system is set lower than the frequency of the load. As implemented in the article, the procedure can be used for back-of-the-envelope estimations, or for achieving an efficient final design. The designs achieved by the suggested methodology are compared to the current traditional design, optimal design achieved through gradient-based sizing optimization, and designs with various common topologies. The methodology’s high potential and its proximity to optimal for a chosen topology are revealed.</p

BMBF-MOS-Kooperation: Foerderung wassertechnologischer F und E-Vorhaben im Rahmen der deutsch-israelischen Zusammenarbeit auf wissenschaftlich technischem Gebiet Schlussbericht

Available from TIB Hannover: F03B1465+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

THEORY AND APPLICATION TO THE US MILITARY

An ever-growing share of defence R&D expenditures is being dedicated to the development and fielding of integrative technologies that enable separate individual systems to work in a coordinated and synergistic fashion as a single system. This study explores the optimal defence budget allocation to the development and acquisition of weapon systems and to the development of integrative technologies. We develop a suitable optimization framework, and then use it to derive the optimal budget allocation and analyse its properties. Finally, we use US defence budget data to calibrate the parameters of the model and provide a quantitative measure for the apparent US military supremacy.Research and Development, Integrative technologies, Budget allocation,