scholarly journals Research on Optimal Placement of Actuators of High-Rise Buildings Considering the Influence of Seismic Excitation on Structural Modes

Buildings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 8
Author(s):  
Jiarui Zhang ◽  
Yaoyang Zhu ◽  
Zhao Li ◽  
Jianwei Tu

Presently, most of the common placement methods of actuators are based on the structural response and system energy to select the optimal locations. In these methods, the contribution of controllability and the energy of seismic excitations to each mode of the structure are not considered, and a large number of cases need to be calculated. To solve this problem, the Clough–Penzien spectral model is combined with the Luenberger observable normal form of the system to calculate the energy of each state. The modal disturbance degree, considering modal energy and controllability, is defined by using the controllability gramian matrix and PBH system controllability index, and the modes are divided into the main disturbance modes (MDMs) and the secondary disturbance modes (SDMs). A novel optimal placement method of actuators based on modal controllability degree is proposed, which uses MDMs as the main control modes. The optimal placement of actuators and the vibration control simulation of a 20-story building model are carried out. The results show that the vibration reduction effect of the proposed placement method is significantly better than that of the method of uniformly distributed actuators (Uniform method) and the classical placement method of actuators based on the system controllability gramian matrix (Classical method).

Author(s):  
Zorigt Tumurbaatar ◽  
Haruyuki Yamamoto

This study is related to decreasing size of stiffness matrix of high-rise building by using floor diaphragm constraints. The combined actions of horizontal structural members such as slab and beams produce structural response that is much stiffer than vertical elements such as columns. In structural analysis of high-rise building model, absolute rigid slab and vertical structure are working together for lumped mass method. Each lumped mass node has 6 degree of freedoms which is very suitable for high-rise building calculation. The lumped mass is consisted of slab and beams, on the other hand the system’s stiffness matrix is only assembly of columns and braces. High-rise building lumped mass model’s stiffness matrix size is n=6 x m (n; total size of stiffness matrix, m; total floor number). In the step by step calculation, total unknown number is decrease enough which means we can easily calculate high-rise building structures for dynamic analysis also nonlinear step by step calculation using simple personal computer. If building model has large span and short height, in this case rigid slab theory will not satisfied. This idea is more suitable for high-rise building calculation.


2021 ◽  
Vol 11 (8) ◽  
pp. 3315
Author(s):  
Fabio Rizzo

Experimental wind tunnel test results are affected by acquisition times because extreme pressure peak statistics depend on the length of acquisition records. This is also true for dynamic tests on aeroelastic models where the structural response of the scale model is affected by aerodynamic damping and by random vortex shedding. This paper investigates the acquisition time dependence of linear transformation through singular value decomposition (SVD) and its correlation with floor accelerometric signals acquired during wind tunnel aeroelastic testing of a scale model high-rise building. Particular attention was given to the variability of eigenvectors, singular values and the correlation coefficient for two wind angles and thirteen different wind velocities. The cumulative distribution function of empirical magnitudes was fitted with numerical cumulative density function (CDF). Kolmogorov–Smirnov test results are also discussed.


2018 ◽  
Vol 192 ◽  
pp. 02002 ◽  
Author(s):  
Yanuar Haryanto ◽  
Buntara Sthenly Gan ◽  
Nanang Gunawan Wariyatno ◽  
Eva Wahyu Indriyati

We evaluated the performance of a high-rise residential building model in Purwokerto, Indonesia due to the seismic load. The evaluation was performed based on seismic loads given in the 2002 and 2012 Indonesian National Standard (SNI) using linear static analysis, dynamic response analysis and pushover analysis. Based on the linear static analysis, the drift ratio decreased by an average of 34.42 and 32.61% for the X and Y directions respectively. Meanwhile, based on the dynamic response analysis, the drift ratio also decreased by an average of 30.74 and 27.33% for the X and Y directions respectively. In addition, the pushover analysis indicates that the performance of this high-rise residential building model is still at Immediate Occupancy (IO) level. The post-earthquake damage state in which the building remains safe to occupy, essentially retaining the pre-earthquake design strength and stiffness of the structure. The risk of life-threatening injury as a result of structural damage is very low. Although some minor structural repairs may be appropriate, these would generally not be required prior to re-occupancy.


Author(s):  
S. J. Dyke ◽  
B. F. Spencer ◽  
M. K. Sain ◽  
J. D. Carlson

Abstract In this paper, the efficacy of magnetorheological (MR) dampers for seismic protection of structures is investigated through a series of experiments in which an MR damper is used to control a three story test structure subjected to a one-dimensional earthquake motion. Because of the intrinsic nonlinearity of the MR damper, several earthquake amplitudes are considered to investigate the performance, in terms of both peak and rms responses, of this control systems over a range of loading conditions. The results indicate that the MR damper is quite effective for structural response reduction over a wide class of seismic excitations.


Author(s):  
Fabio Rizzo ◽  
Alessandro Pagliaroli ◽  
Giuseppe Maddaloni ◽  
Antonio Occhiuzzi ◽  
Andrea Prota

<p>The paper discusses results of shaking table tests on an in-scale high-rise building model. The purpose was to calibrate a dynamic numerical model for multi-hazard analyses to investigate the effects of floor acceleration. Accelerations, because of vibration of non-structural elements, affect both the comfort and safety of people. The research investigates the acceleration effects of both seismic and wind forces on an aeroelastic in-scale model of a multi-story building. The paper discusses the first phase of experiments and gives results of floor accelerations induced by several different base seismic impulses. Structural analyses were first performed on the full-scale prototype to take soil-structure interaction into account. Subsequently the scale model was designed through aeroelastic scale laws. Shaking table experiments were then carried out under different base accelerations. The response of the model and, in particular, amplification of effects from base to top are discussed.</p>


2018 ◽  
Vol 65 ◽  
pp. 08008
Author(s):  
Syed Muhammad Bilal Haider ◽  
Zafarullah Nizamani ◽  
Chun Chieh Yip

The reinforced concrete structures, not designed for seismic conditions, amid the past earthquakes have shown us the significance of assessment of the seismic limit state of the current structures. During seismic vibrations, every structure encountered seismic loads. Seismic vibrations in high rise building structure subjects horizontal and torsional deflections which consequently develop extensive reactions in the buildings. Subsequently, horizontal stiffness can produce firmness in the high rise structures and it resists all the horizontal and torsional movements of the building. Therefore, bracing and shear wall are the mainstream strategies for reinforcing the structures against their poor seismic behaviours. It is seen before that shear wall gives higher horizontal firmness to the structure when coupled with bracing however it will be another finding that in building model, which location is most suitable for shear wall and bracing to get better horizontal stability. In this study, a 15 story residential reinforced concrete building is assessed and analyzed using building code ACI 318-14 for bracing and shear wall placed at several different locations of the building model. The technique used for analysis is Equivalent Static Method by utilizing a design tool, finite element software named ETABS. The significant parameters examined are lateral displacement, base shear, story drift, and overturning moment.


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