Stability of the yield displacement

Author(s):  
Mark Aschheim ◽  
Enrique Hernández ◽  
Dimitrios Vamvatsikos
Keyword(s):  
2020 ◽  
Vol 20 (05) ◽  
pp. 2050062
Author(s):  
Huiying Hu ◽  
Lincong Chen

As a new type of seismic resisting device, the self-centering system is attractive due to its excellent re-centering capability, but research on such a system under random seismic loadings is quite limited. In this paper, the stochastic response of a single-degree-of-freedom (SDOF) self-centering system driven by a white noise process is investigated. For this purpose, the original self-centering system is first approximated by an auxiliary nonlinear system, in which the equivalent damping and stiffness coefficients related to the amplitude envelope of the response are determined by a harmonic balance procedure. Subsequently, by the method of stochastic averaging, the amplitude envelope of the response of the equivalent nonlinear stochastic system is approximated by a Markovian process. The associated Fokker–Plank–Kolmogorov (FPK) equation is used to derive the stationary probability density function (PDF) of the amplitude envelope in a closed form. The effects of energy dissipation coefficient and yield displacement on the response of system are examined using the stationary PDF solution. Moreover, Monte Carlo simulations (MCS) are used for ascertaining the accuracy of the analytical solutions.


2010 ◽  
Vol 168-170 ◽  
pp. 2434-2438 ◽  
Author(s):  
Yan Hong Xu ◽  
Ai Qun Li ◽  
Xing De Zhou ◽  
Peng Sun

This paper presented a new mild steel slit damper(SSD). The new shape was parabolic according to all the cross section having the same maximal stress, and the elastic stiffness and yield displacement formula were derived. Finite element analysis showed that the parabolic shaped damper had a more reasonable load - displacement curve compared with the previously proposed shape. The theoretical stiffness and yield displacement were consistent with the results by finite element method (FEM), and that indicated the presented design method was simple and feasible.


Author(s):  
SL Cheng ◽  
SY Du ◽  
XS Yan ◽  
Q Guo ◽  
YJ Xin

Two types of clapboard-type lead dampers were designed based on plastic energy absorption of lead metal. The hysteretic curves and energy dissipation properties were studied through low cyclic loading test. Also, the typical restoring load model was extracted. The finite-element numerical model of type-A damper was build according to the characteristics and principle of clapboard-type lead dampers. And the damping effect of high-structural Benchmark model installed with type-A damper was analyzed. The results show that the structure of clapboard-type lead dampers is simple, hysteretic curves are plump, hysteretic properties are steady and yield displacement is small, and thus its energy dissipation ability is excellent. The models of finite element and restoring load of dampers are in good agreement with the results of tests, so they have good applicability. The seismic system installed with type-A dampers has an excellent vibration reduction effect. The top-floor acceleration and displacement control effects are 26.7% and 37.4%, respectively.


2014 ◽  
Vol 541-542 ◽  
pp. 857-860
Author(s):  
Wei Zhou ◽  
Xiao Xu ◽  
Wen Xiu Hao

Friction energy dissipating bracing is the kind of efficient system in reducing seismic of buildings. The main parameters are bracing stiffness and yielding displacement of friction energy dissipating devices in this system, which are important to the design of reducing seismic systems. Five-story steel frame building model with friction energy dissipating bracing in each floor is established, whose dynamic response of structure is studied when the value of main parameters is changed. The results show that the displacement of structure are decreased obviously and the acceleration of structure is first decreased and then increased when the bracing stiffness and yield displacement of friction energy dissipating devices are increased. In addition, the rational range of parameters is suggested for the design of friction energy dissipation systems.


2013 ◽  
Vol 07 (02) ◽  
pp. 1350007 ◽  
Author(s):  
LINING DING ◽  
GANG WU ◽  
SHENYIN YANG ◽  
ZHISHEN WU

Basalt fiber reinforced polymer (BFRP) composites are regarded as promising structural strengthening material due to their environmental friendly and superior mechanical and chemical properties. In order to enhance the overall seismic performance of RC columns, a strengthening system is developed by applying BFRP composites with both near surface mounted (NSM) and confinement approaches. The variables taken into account consisted of the diameters and anchorage lengths of BFRP bars, as well as the confinement amounts of BFRP sheets. A total of eight column specimens including one control were tested subjected to simultaneous axial compression and cyclic bend. The structural performance such as load capacity, displacement, ductility, stiffness degradation, energy dissipation capacity, curvature and post-yield stiffness were investigated. The test results indicate that the combination of NSM and confinement techniques contributes to the comprehensive performance enhancement of RC columns, which lies in (1) constantly enlarging diameters of BFRP bars increases the yield and peak loads, the ultimate displacement, the initial and post-yield stiffness as well as the ductility, whereas it has no obvious influence on the yield displacement; (2) longer bonding length results in higher seismic performances although it makes no changes to the yield displacement, the post-yield stiffness, and the degradation of strength and stiffness as well; (3) the adoption of BFRP confinement significantly improves the ductility and the strength degradation performance; (4) the largest post-yield stiffness can be achieved by enlarging diameter to 12 mm, whereas the ductility and the strength degradation characteristics deteriorate due to the weakness of interfacial bonding between BFRP bars and concrete.


2011 ◽  
Vol 374-377 ◽  
pp. 2471-2479
Author(s):  
Rong Tang ◽  
Yun Zhou ◽  
Xue Song Deng ◽  
Shao Ming Lin

According to the philosophy of “partially weaken the core element of the BRB to protect the other part”, 12 specimens of the Triple Square Steel Tube Buckling-Restrained Brace (TSST-BRB) were designed with which the core element had notched. ABAQUS finite element method was used to investigate the performance of TSST-BRB with different notched kinds, number, length and depth of the core element. The analysis results indicated that the core element with annular notch was conducive to reduce the stress concentration of ends, and dissipate energy under tiny displacement. Two notches of the core element were better to reduce the peak stress of the notched segment and the stress concentration of ends. The length of notch should be controlled on 13.3%~20.0% of the length of core element. The energy dissipation capacity, yield displacement and yield capacity of the TSST-BRB were significantly influenced by the depth of notched core element. The depth of the notch should be controlled on 10%~23.3% of the thickness of core element.


2014 ◽  
Vol 937 ◽  
pp. 531-536
Author(s):  
Chao Xu ◽  
Yong Feng Niu ◽  
Yong Xie Zhao

To the H-shaped Mild steel damper which has been applied to the market, this paper proposes the opening box dampers were made in material Q235 steel. Studied the influence of the angular size between Webs and vertical direction to the box-shaped Mild steel damper by FEM ABAQUS. The results indicated that under the same rate in the web openings, box dampers has the same yield displacement and hysteresis curves were fuller than H-shaped dampers. With the increase of web and vertical angles, the initial stiffness of the damper box steel and yield strength and yield stiffness of the damper would reduced, but all of these are larger than H-shaped steel dampers; Meanwhile, moment of inertia of box dampers’ two webs to Y-axis is larger , which greatly enhancing the stability of the outside plane to the damper, the larger Web angles, the stronger yield strength and the stability of the outside plane.


2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Hang Lin ◽  
Youyan Zhu ◽  
Jianyu Yang ◽  
Zhijie Wen

Bolts are widely used in rock mass engineering, wherein the bolt support improves the safety and stability of the rock mass. To reveal the mechanical behavior of the bolt and failure mechanism of the bolted joint in the shearing process, a direct shear test was conducted by changing the state of grouting, number of bolt, and inclination angle of the bolt. The change in the axial force of the anchor in the shearing process was evaluated by conducting a strain gauge test, and the mechanical behavior of the bolt under the external force was studied. The results showed that under the same normal stress, the yield displacement of the bolt decreased and the stiffness of the joint gradually increased with increased number of bolts. At the same number of bolts, their yield displacement increased with increased normal stress. Analysis further revealed that grouting on the joint improved the force condition of the bolt, increased the yield displacement of the bolt, and coordinated the deformation of the grouting body and bolt, thereby improving the shear strength of the joint. Lastly, when the anchor angles differed, the axial pulling resistance of the anchor changed, and the yield displacement of the anchor with 45° inclination was <90°. The yield displacement of the bolt showed that the supporting effect of the bolt with a 45° inclination was better than that of the bolt with a 90° inclination.


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