Dynamics of structures

PART 1 DEALS WITH THE DYNAMIC ASPECTS OF THE SUBJECT: MATHEMATICAL ANALYSIS OF SYSTEMS SUBJECTED TO INDEPENDENT VIBRATIONS BY MEANS OF MATHEMATICAL MODELS. THE ANALYTICAL SYSTEMS USED ARE NON-LINEAR SYSTEMS, HYDRODYNAMICS AND NUMERICAL METHODS. PART 2 EXAMINES SEISMIC MOVEMENTS, THE DYNAMIC BEHAVIOUR OF STRUCTURES AND THE BASIC CONCEPTS OF THE SEISMIC DESIGN OF STRUCTURES.

Fundamentals of earthquake engineering

Design strategies of viscous dampers for seismic protection of building structures: A review

In the recent years, increasing attention has been posed towards enhancing the sustainability of manufacturing processes by reducing the consumption of resources and key materials, the energy consumption and the environmental footprint, while also increasing companies’ competitiveness in global market contexts. De- and remanufacturing includes the set of technologies/systems, tools and knowledge-based methods to recover and reuse functions and materials from industrial waste and post-consumer products, under a Circular Economy perspective. This new paradigm can potentially support the sustainability challenges in strategic manufacturing sectors, such as aeronautics, automotive, electronics, consumer goods, and mechatronics. A new generation of smart de- and remanufacturing systems showing higher levels of automation, flexibility and adaptability to changing material mixtures and values is emerging and there is a need for systematizing the existing approaches to support their operations. Such innovative de- and remanufacturing system design, management and control approaches as well as advanced technological enablers have a key role to support the Circular Economy paradigm. This paper revises system level problems, methods and tools to support this paradigm and highlights the main challenges and opportunities towards a new generation of advanced de- and remanufacturing systems.

Design, management and control of demanufacturing and remanufacturing systems

Seismic response mitigation of a wind turbine tower using a tuned parallel inerter mass system

This study improves upon the traditional polynomial detrending method in order to correct the vibration acceleration signals with inconsistent initial velocity and displacement more rationally and efficiently. When numerical integration of recorded acceleration signals using assumed initial velocity and displacement values (which are generally inconsistent with real values) is performed, baseline shift or drift phenomenon can arise in velocity and displacement curves obtained. Baseline correction must be performed if an inconsistent acceleration signal is to be used in dynamic analyses. Polynomial detrending is generally used to remove unreasonable trends in time series, but the consistency among acceleration, velocity, and displacement has not received sufficient attention. The traditional polynomial detrending method is improved by purposefully removing the shifted trends in velocity and displacement. Two inconsistent vibration signals are selected to be corrected using both the traditional method and t...

https://journals.sagepub.com/doi/pdf/10.1177/1687814016675534

Baseline correction of vibration acceleration signals with inconsistent initial velocity and displacement

Summary
In this study, a demand-based optimal design method is proposed for an oscillator (a single-degree-of-freedom system) with a parallel-layout viscous inerter damper (PVID) The proposed design method overcomes some deficiencies of the existing method, which is based on the fixed-point theory and is mainly suitable for tuned mass dampers Moreover, for the fixed-point method, the inherent damping of the primary structure is neglected, and the global optimal solution cannot be obtained The proposed method can obtain a more rational and practical design for the actual design by minimizing both the response and the cost The design problem of a PVID-equipped oscillator is transformed into a multi-objective optimization problem that can be solved using the e-constraint approach, which is consistent with the concept of demand-based design The dynamic response of the oscillator and the force of the PVID (ie, the cost factor) are evaluated according to theories of random vibration to reduce the number of calculations required A computer program is developed to perform demand-based parametric design of a PVID-equipped oscillator Several design cases were examined under different excitation conditions using the computer program, and dynamic time history analyses were then conducted to verify the designs obtained The results show that the proposed optimal design method identifies satisfactory designs more effectively than the existing method by obtaining PVID design parameter values that better meet the performance demand and simultaneously minimize the cost

Ruifu Zhang

Papers

Baseline correction of vibration acceleration signals with inconsistent initial velocity and displacement

Seismic response mitigation of a wind turbine tower using a tuned parallel inerter mass system

Demand-based optimal design of oscillator with parallel-layout viscous inerter damper

Design of structure with inerter system based on stochastic response mitigation ratio

Damping enhancement principle of inerter system