This paper presents some of the oral discussion by the author and others at the 2005 Annual Meeting of the Los Angeles Tall Buildings Structural Design Council. It also includes additional opinions added by the author after the annual meeting. These opinions address the development of a new building code for tall buildings and where the non-structural engineering decision makers can and must make contributions. It also addresses the very important topic of quality control. Copyright © 2005 John Wiley & Sons, Ltd.

The structural design of tall and special buildings

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 work studies the advantageous features of the fluid inerter device for optimised structural control of buildings. Experimental data are first presented to characterise the fluid inerter dynamics, and validate the simplified analytical formulations. Building on these observations, the device is modelled as an inerter in parallel with a nonlinear dashpot representing a power law damping term. The latter dissipative effects are mainly induced by the pressure drops occurring in helical channels due to the fluid viscosity and density. Then, novel passive vibration control schemes are implemented for the earthquake protection of base-isolated buildings by combining the fluid inerter with a tuned mass damper system. To account for the uncertain nature of the earthquake input, the base acceleration is modelled as a Kanai–Tajimi filtered stationary random process. The optimal fluid inerter parameters, namely inertance and damping, are identified numerically by minimising stochastic performance indices relevant to displacement, acceleration, and energy-based measures of the structural response. The nonlinear damping behaviour of the fluid inerter is fully incorporated in the optimal design procedure via the statistical linearisation technique. Nonlinear response history analysis under an ensemble of 44 natural earthquake ground motions is carried out to assess the seismic performance of the system. Since inertance and damping are coupled characteristics in a real fluid inerter, design guidelines are finally outlined to determine the actual geometrical and mechanical properties of the device to achieve targeted parameters resulting from the optimisation procedure.

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Novel fluid inerter based tuned mass dampers for optimised structural control of base-isolated buildings

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

Chao Pan

Papers

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

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

A tuned liquid inerter system for vibration control