Study on Time History Method of Structure with Energy-Dissipation Devices Based on Complex Mode

2011 ◽  
Vol 94-96 ◽  
pp. 1192-1195
Author(s):  
Zhi Qiang Bai ◽  
Wen Feng Liu

Differential equation of motion of energy-dissipation structure is established in the paper. In order to decouple the equation ,the equation is be reduced based on complex mode theory.Take a 10-storey shearing frame for an example ,selecting elcentro and taft wave as seismic motions ,structural roof displacements and relative storey displacements are be calculated and the effect of energy-dissipation dampers is evaluated.

2012 ◽  
Vol 204-208 ◽  
pp. 1150-1153
Author(s):  
Min Chen ◽  
Guo Jing He ◽  
Chang Liu

Energy dissipation structure is favored by designers because the earthquake energy can be dissipated by the dampers, which can avoid or reduce the damage caused by earthquake. However, the energy dissipation structure design is complex and the most domestic designers can not master it easily. In this paper, a simple and practicable design method for viscous damper dissipation structure by using the PKPM design software is proposed based on a 7-storey frame structure in highly seismic region. Firstly, lower half or one degree for the design intensity to design out an uncontrolled structure. Secondly, determine the supplemental damping ratio required for the fortification intensity via modal analysis method of PKPM software, and identify the numbers of the required dampers as well as their corresponding installation positions in line with the methods in the seismic code of China. Finally, the ETABS program is adopted to conduct the time-history analysis of the designed dissipation structure, showing that the proposed method in this paper can produce a satisfied result.


2021 ◽  
Vol 1203 (3) ◽  
pp. 032045
Author(s):  
Chenhao Wu

Abstract Precast concrete frames (PCFs) with "dry" connections and self-centering capacity have been proposed as a new kind of seismic protective structural system with characteristics of damage controllable mechanism, easy-assemblage and rapid repair speed. The damage mechanism of PCFs are concentrated at the panel zones under earthquake excitations, so as to avoid damage to beam and column components. Through reasonable design for the PCFs, not only the structural and life safeties can be guaranteed, but also the seismic loss and social impact can be minimized. This paper conducts a comparative study between PCFs with "dry" connections and conventional cast-in-situ concrete frame. A generalized beam-column connection analytical model is utilized to predict the seismic behaviour of PCFs with energy dissipation devices, with an emphasis on the opening behaviour at beam-column interfaces, the self-centering capacity provided by prestressed tendons and the hysteresis behaviour provided by energy dissipation devices. Prototype PCFs or cast in situ frame structures are designed to achieve similar deformation capacities in Chinese highly seismic fortification zone. Probabilistic seismic capacity analyses (PSCA) are conducted based on the results of probabilistic pushover analyses and Latin Hypercube Sampling. Incremental dynamic analysis method combined with nonlinear time history analyses are utilized to conduct probabilistic seismic demand analyses (PSDA). Fragility functions of different structural systems are derived based on the convolution of PSCA and PSDA. Finally, the seismic risk is evaluated based on the fragility functions and the developed Chinese seismic code compliant hazard functions. The results indicate that PCFs with energy dissipation devices can have lower seismic risk than conventional cast-in-site frames.


2021 ◽  
Vol 1203 (2) ◽  
pp. 022075
Author(s):  
Fangqian He ◽  
Ting Zhang

Abstract In practical application, the design of energy dissipation usually adopts the concept design, that is, to estimate damper quantity by repeating calculation. However, few studies have quantitatively analyzed the energy dissipation structure. This paper proposed two analysis methods to analysis the damper quantity of energy dissipation structure, the multiple-yield-strength method, and the damping-performance-curve method. Both of them can calculate the optimal damping quantity of the structure by adding metal dampers. The multiple-yield-strength method refers to that the yield strength of the metal damper is set by the multiple of the yield strength of the original structure. The optimal damper quantity of metal dampers can be analyzed by time history analysis. The damping-performance-curve method refers to that the target story displacement of the original structure is set. According to the relationship between the target displacement and the shear force in the damping-performance-curve, the stiffness of the original structure to achieve the target story displacement angle is derived, the stiffness is taken as the optimal damping of the metal damper. The optimal damping quantity is added to the original structure for comparative study which is calculated by the two methods. Both of them have reference value, and it could be beneficial for the promotion of energy dissipation.


2014 ◽  
Vol 580-583 ◽  
pp. 1591-1594
Author(s):  
Yun Chen ◽  
Nai Long Zhu ◽  
Shuai Gao

This paper proposes an energy dissipation device based on shape memory alloys (SMA) for frame structures. By setting anchorage device below and near the inflection point of the first storey columns, a set of force cable and energy dissipation cable using SMA are installed symmetrically in the anchorage device and the bottom of them fixed in the ground. Analytical study including the push-over and time-history analysis were investigated by ANSYS finite element program to a new CFST frame and an ordinary CFST frame. Studies have shown that the device can effectively control the structural displacement response and acceleration response, dissipating large amounts of earthquake energy. Therefore, the energy dissipation devices had a better value and prospects in engineering.


2018 ◽  
Vol 763 ◽  
pp. 867-874
Author(s):  
Yu Shu Liu ◽  
Ke Peng Chen ◽  
Guo Qiang Li ◽  
Fei Fei Sun

Buckling Restrained Braces (BRBs) are effective energy dissipation devices. The key advantages of BRB are its comparable tensile and compressive behavior and stable energy dissipation capacity. In this paper, low-cycle fatigue performance of domestic BRBs is obtained based on collected experimental data under constant and variable amplitude loadings. The results show that the relationship between fatigue life and strain amplitude satisfies the Mason-Coffin equation. By adopting theory of structural reliability, this paper presents several allowable fatigue life curves with different confidential levels. Besides, Palmgren-Miner method was used for calculating BRB cumulative damages. An allowable damage factor with 95% confidential level is put forward for assessing damage under variable amplitude fatigue. In addition, this paper presents an empirical criterion with rain flow algorithm, which may be used to predict the fracture of BRBs under severe earthquakes and provide theory and method for their engineering application. Finally, the conclusions of the paper were vilified through precise yet conservative prediction of the fatigue failure of BRB.


Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 631-641
Author(s):  
Shujuan Yang

AbstractIn view of the problem of large earthquake displacement in the use of the original concrete engineering shear wall reinforcement method, the energy dissipation and damping structure is used to design the energy dissipation and damping structure reinforcement method in the concrete engineering shear wall. According to the design process of the set method, the anti-vibration coefficient of the concrete shear wall is tested. The energy dissipation structure is used to construct a shear damping wall, and the damper is added to the original shear wall. The concrete shear wall is strengthened by sticking steel technology. So far, the design of shear wall reinforcement method based on the energy dissipation structure has been completed. Compared with the original method, the displacement distance of this method is lower than that of the original method. In conclusion, the effect of shear wall reinforcement method based on the energy dissipation structure is better than that of the original method.


Author(s):  
Ben Carmichael ◽  
Gary Frey ◽  
S. Nima Mahmoodi

Mechanical characterization of thin samples is now routine due to the prominence of the Atomic Force Microscope. Advances in amplitude modulation techniques have allowed for accurate measurement of a sample’s elastic properties by interpreting the changes in the vibration of a cantilevered beam in intermittent contact. However, the nonlinearities associated with contact complicate attempts to find an accurate time-history for the beam. Furthermore, the inclusion of viscous effects, common to soft samples, puts an explicit solution even farther from reach. A numerical method is proposed that analyzes the time-history and frequency response of a microcantilever beam with a viscoelastic end-condition. The mathematics can be simplified by incorporating the viscoelastic end-condition into the equation of motion directly by modeling it as a distributed load. A forcing function can then be derived from the Standard Linear Solid model of viscoelasticity and implemented in the non-conservative work term of Hamilton’s principle. The Galerkin method can separate the resulting nonlinear equation of motion into time and space components. Performing a numerical analysis of the time factor equation provide the beam’s response over time. The results demonstrate the distinctive effects of viscoelasticity and periodic contact on the beam’s motion and provide the framework for the determination of viscous properties using dynamic techniques.


2012 ◽  
Vol 594-597 ◽  
pp. 886-890 ◽  
Author(s):  
Gan Hong ◽  
Mei Li ◽  
Yi Zhen Yang

Abstract. In the paper, take full account of energy dissipation operating characteristics. Interlayer shear-frame structure for the analysis of the Wilson-Θmethod ELASTOPLASTIC schedule, the design of a nonlinear dynamic time history analysis procedure. On this basis, taking into account the restoring force characteristics of the energy dissipation system, the inflection point in the restoring force model treatment, to avoid a result of the calculation results of distortion due to the iterative error. A frame structure seismic response time history analysis results show that: the framework of the energy dissipation significantly lower than the seismic response of the common framework, and its role in the earthquake when more significant.


2014 ◽  
Vol 1030-1032 ◽  
pp. 223-227
Author(s):  
Lin Fan ◽  
Song Rong Qian ◽  
Teng Fei Ma

In order to analysis the force situation of the material which is discontinuity,we can used the new theory called peridynamics to slove it.Peridynamics theory is a new method of molecular dynamics that develops very quickly.Peridynamics theory used the volume integral equation to constructed the model,used the volume integral equation to calculated the PD force in the horizon.So It doesn’t need to assumed the material’s continuity which must assumed that use partial differential equation to formulates the equation of motion. Destruction and the expend of crack which have been included in the peridynamics’ equation of motion.Do not need other additional conditions.In this paper,we introduce the peridynamics theory modeling method and introduce the relations between peridynamics and classic theory of mechanics.We also introduce the numerical integration method of peridynamics.Finally implementation the numerical integration in prototype microelastic brittle material.Through these work to show the advantage of peridynamics to analysis the force situation of the material.


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