Real-time hybrid simulations vs shaking table tests: Case study of a fibre-reinforced bearings isolated building under seismic loading

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Summary This paper describes the results of bidirectional shaking‐table tests performed on novel, low‐cost, and eco‐friendly recycled‐rubber fiber‐reinforced bearings (RR‐FRBs). The research aims to demonstrate the adequacy of square bearings made of recycled rubber when it comes to performing a base isolators in low‐rise residential buildings in developing regions of the world. The results of shear tests on RR‐FRBs are described in this paper as well as the response of a base‐isolated prototype building under bidirectional ground‐motion excitation. Compared with the results of a fixed‐base structure, the peak drift ratio, peak base shear, and peak acceleration on the different floors are significantly reduced for the base‐isolation system of the RR‐FRBs. The results of this work confirm the option of adopting RR‐FRBs as base isolators in real structures, with the stability of the devices under major bidirectional excitation requiring further investigation.

Section: Recycled‐rubber Fiber‐reinforced Bearingsmentioning

confidence: 99%

“…The testing apparatus and its capabilities are described in the previous studies. 20,21 The frequency of the imposed displacement was 0.87 Hz and the displacement amplitudes ranged from 10 to 45 mm. Figure 2a shows the time history of the applied displacement and Figure 2b the measured response.…”

Section: Description Of the Tested Rr-frbsmentioning

confidence: 99%

Bidirectional shaking‐table tests of unbonded recycled‐rubber fiber‐reinforced bearings (RR‐FRBs)

Losanno

Spizzuoco

Calabrese

2019

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“…Hybrid simulation (HS) is a dynamic simulation paradigm that allows for investigating the experimental response of large‐ or even full‐scale structural prototypes with reduced costs compared with shake table testing . In detail, HS isolates the physical substructure (PS), which is experimentally tested, because it contains a key region (or component) exhibiting nonlinear behavior, from the remainder of the system, which is numerically simulated, that is, the numerical substructure (NS).…”

Section: Introductionmentioning

confidence: 99%

A computational framework for fast‐time hybrid simulation based on partitioned time integration and state‐space modeling

Abbiati

Lanese

Cazzador

et al. 2019

Summary Hybrid simulation reproduces the experimental response of large‐ or even full‐scale structures subjected to a realistic excitation with reduced costs compared with shake table testing. A real‐time control system emulates the interaction between numerical substructures, which replace subparts having well‐established computational models, and physical substructures tested in the laboratory. In this context, state‐space modeling, which is quite popular in the community of automatic control, offers a computationally cheaper alternative to the finite‐element method for implementing nonlinear numerical substructures for fast‐time hybrid simulation, that is, with testing timescale close to one. This standpoint motivated the development of a computational framework based on partitioned time integration, which is well suited for hard real‐time implementations. Partitioned time integration, which relies on a dual assembly of substructures, enables coupling of state‐space equations discretized with heterogeneous time step sizes. In order to avoid actuators stopping at each simulation step, the physical substructure response is integrated with the same rate of control system, whereas a larger time step size is allowed on the numerical substructure compatibly with available computational resources. Fast‐time hybrid simulations of a two‐pier reinforced concrete bridge tested at the EUCENTRE Experimental Laboratory of Pavia, Italy, are presented as verification example.

“…Hybrid simulation (HS) represents an effective method to investigating the dynamic behavior of structures with large or even full‐scale test prototypes in an inexpensive way . In particular, HS isolates the physical substructures (PSs), which is experimentally tested because it contains a key region (or component) exhibiting nonlinear behavior, from the remainder of the system, which is numerically simulated, that is, the numerical substructures (NSs).…”

Section: Introductionmentioning

confidence: 99%

“…KEYWORDS concrete constitutive law, hybrid simulation, online model updating, OpenSEES, unscented Kalman filter 1 | INTRODUCTIONHybrid simulation (HS) represents an effective method to investigating the dynamic behavior of structures with large or even full-scale test prototypes in an inexpensive way. [1][2][3][4] In particular, HS isolates the physical substructures (PSs), which is experimentally tested because it contains a key region (or component) exhibiting nonlinear behavior, from the remainder of the system, which is numerically simulated, that is, the numerical substructures (NSs). As a result, no explicit dynamic model of the PS is required, and the evaluation of any internal nonlinear dynamic behavior can be experimentally examined by including the PS in the real-time-or close to real-time-substructuring loop.…”

mentioning

confidence: 99%

Hybrid simulation of structural systems with online updating of concrete constitutive law parameters by unscented Kalman filter

Mei

Bursi

et al. 2017

Summary Online model updating in hybrid simulation (HS) can represent an effective technique to reduce modeling errors of parts numerically simulated, that is, numerical substructures, especially when only a few critical components of a large system can be tested, that is, physical substructures. As a result, in an enhanced HS with online model updating, parameters of constitutive relationship can be identified based on experimental data provided by physical substructures and updated in numerical substructures. This paper proposes a novel method to identify constitutive parameters of concrete laws with unscented Kalman filter (UKF). In order to implement UKF, parts of the source codes of the OpenSEES software were modified to compute estimated measurements. Prior to experimental HS, a parametric study of UKF constitutive law parameters was conducted. As a result, the effectiveness of the UKF combined with OpenSEES was validated through numerical simulations, a monotonic loading test on a concrete column and real‐time HSs of a reinforced concrete frame run with both standard and model‐updating techniques based on UKF.