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

Abstract

SummaryIn 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 ε-constraint approach, which is consistent with the concept of demand-based design. The dynamic response of the oscillator and the force of the PVID (i.e., 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. | INTRODUCTIONStructural vibrations induced by earthquake or wind loads can be attenuated by various means, including modifying the stiffness, masses, damping, or shape of the structure, and by providing passive or active counter forces.[1] Among numerous available methods, passive mitigation measures are the most widely used in building and bridge engineering. Passive vibration mitigation involves providing a structure with additional damping by installing dampers, and the effectiveness of damping has been confirmed by extensive scientific studies and practical applications. Many types of dampers are used in the passive vibration mitigation of building structures all over the world, such as metalyield dampers, friction dampers, viscoelastic dampers, viscous fluid dampers, tuned mass dampers, and tuned liquid dampers. The concept of tuned mass dampers dates back to the 1900s, when Frahm [2] introduced a tuned mass damper (TMD) to absorb the energy of vibrations, thereby reducing the amplitudes of motions. Den Hartog [3] modified the original TMD concept in the

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

“…Therefore, the selection of a rational parameter set for the design of SPIS‐II based on only the displacement response is difficult. The control cost, which can be represented by the force response of the inerter system, should be considered in the case of SPIS‐II, as determined in a previous study . Hence, the variation patterns of the force response for SPIS‐II (in the form of the dimensionless root‐mean‐square response ) were also obtained in the present study, as shown in Figure , in which.…”

“…(b) A comparison of the M1 and M3 results reveals that M1 produces higher displacement and force responses for a given inerter‐mass ratio μ . (c) A comparison of the M1 and M4 results indicates that the demand‐based numerical optimization method is equivalent to the presently proposed response mitigation method.…”

Demand-Based Optimal Design of Storage Tank with Inerter System

“…According to the actual production capacity and device design requirements, the fluctuation in the sloshing height of the liquid in the storage tank will reach the minimum value at a high control cost within the range of the three variable parameters ( , , and ). In the actual optimization design of the VIS, certain control requirements are necessary to lower the control costs [25]. As mentioned above, and are selected as the objective indicators.…”

“…The disadvantage of the fixed method is that it neglects the inherent damping of the primary structure, and a limitation is introduced because an empirically equivalent mass ratio is used. Pan et al [25] developed a demand-based optimal design for a single-degree-of-freedom structure considering the inherent damping ratio of the primary structure.…”

Direct design method based on seismic capacity redundancy for structures with metal yielding dampers

“…1,2 For passive structural response control, hysteretic dampers-generally made of metals with excellent ductility such as mild steel-are widely used as energy dissipation devices (EDDs) to control structural seismic response. 1,2 For passive structural response control, hysteretic dampers-generally made of metals with excellent ductility such as mild steel-are widely used as energy dissipation devices (EDDs) to control structural seismic response.…”