Cyclic Behavior and Simplified Design Method of Hybrid Rocking Columns with External Energy-Dissipators

2020 ◽  
Vol 14 (06) ◽  
pp. 2050026
Author(s):  
Yongxing Li ◽  
Jianzhong Li ◽  
Yu Shen ◽  
Wenjing Xu

In recent years, hybrid rocking columns incorporating post-tensioned (PT) tendons and energy dissipation devices become prevalent on account of the superior self-centering capacity. In this paper, the simplified analysis method based on interface section analysis is employed to conduct parametric analyses on the hybrid rocking columns with external buckling-restrained devices, which are adopted as the external energy-dissipators. The effects of four parameters including the aspect ratio, the initial PT force, the area of PT tendons and the area of energy-dissipators are investigated. Furthermore, a simplified design method for hybrid rocking columns with external energy-dissipators is proposed using the parametric analysis results. In the design procedure, the performance index [Formula: see text] is employed considering the requirement of residual drift. The efficiency of the design method is verified by a numerical design example to show the application. The results show that the design objectives of lateral force and residual drift can be achieved through a small number of iterations.

2012 ◽  
Vol 446-449 ◽  
pp. 1036-1041 ◽  
Author(s):  
Jia Guo ◽  
Ke Gui Xin ◽  
Wei Ping Wu ◽  
Ming Hua He

A self-centring bridge pier is a combination of elastic recovery devices and internal or external energy dissipaters. During the cyclic loading test, it is proved that the self-centring system can minimize the residual drift of the pier whereas holding sufficient energy dissipate capacity as well as bearing capacity. It is worth noting that a simplified analytical model is proposed based on the experimental response regarding flexural deformation, unbounded length of mild steels and strain penetration. Comparison between the analytical model and test results has indicated that a reasonable envelope of the cyclic behavior of the system can be achieved by the model presented.


2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.


2007 ◽  
Vol 31 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Zhang Ying ◽  
Yao Yan-An ◽  
Cha Jian-Zhong

This paper proposed a novel concept of active balancer for dynamic balancing of planar mechanisms. Somewhat similar to a vibration absorber, the active balancer is designed as an independent device, which is placed outside of the mechanism to be balanced and can be installed easily. It consists of a two degree-of-freedom (DOF) linkage with two input shafts, one of which is connected to the output shaft of the mechanism to be balanced by a joint coupling, and the other one is driven by a controllable motor. Flexible dynamic balancing adapted to different working conditions can be achieved by varying speed trajectories of the control motor actively. A design method is developed for selecting suitable speed trajectories and link parameters of the two DOF linkage of the balancer to meet various design requirements and constraints. Numerical examples are given to demonstrate the design procedure and to verify the feasibility of the proposed concept.


ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Suyong Wu ◽  
Xingwu Long ◽  
Kaiyong Yang

We present a novel fast robust design method of multilayer optical coatings. The sensitivity of optical films to production errors is controlled in the whole optimization design procedure. We derive an analytical calculation model for fast robust design of multilayer optical coatings. We demonstrate its effectiveness by successful application of the robust design method to a neutral beam splitter. It is showed that the novel robust design method owns an inherent fast computation characteristic and the designed film is insensitive to the monitoring thickness errors in deposition process. This method is especially of practical significance to improve the mass production yields and repetitive production of high-quality optical coatings.


ce/papers ◽  
2021 ◽  
Vol 4 (2-4) ◽  
pp. 2207-2214
Author(s):  
Antoine Glorieux ◽  
Louis‐Guy Cajot ◽  
François Hanus

Author(s):  
Tsunehiro Wakasugi ◽  
Toru Watanabe ◽  
Kazuto Seto

This paper deals with a new system design method for motion and vibration control of a three-dimensional flexible shaking table. An integrated modeling and controller design procedure for flexible shaking table system is presented. An experimental three-dimensional shaking table is built. “Reduced-Order Physical Model” procedure is adopted. A state equation system model is composed and a feedback controller is designed by applying LQI control law to achieve simultaneous motion and vibration control. Adding a feedforward, two-degree-of-freedom control system is designed. Computer simulations and control experiments are carried out and the effectiveness of the presented procedure is investigated. The robustness of the system is also investigated.


1990 ◽  
Author(s):  
A. Kirschner ◽  
H. Stoff

A cascade design-method is presented which complements the meridional through-flow design procedure of turbomachines. Starting from an axisymmetric flow field and the streamline geometry in the meridional plane this simple method produces a solution for the quasi three-dimensional flow field and the blade-element geometry on corresponding stream surfaces. In addition, it provides intra-blade data on loss and turning required for a consistent design and a convenient means of optimizing blade loading. The purpose of this paper is to describe the theoretical basis of the method and to illustrate its application in the design of transonic compressors.


2018 ◽  
Vol 12 (05) ◽  
pp. 1850015 ◽  
Author(s):  
Wei Guo ◽  
Jianzhong Li ◽  
Nailiang Xiang

In this paper, a novel central buckle composed of buckling-restrained braces (BRBs) is developed for long-span suspension bridges, and its preliminary design procedure is presented. Seismic performance of suspension bridges equipped with BRB central buckles is investigated and compared with those with conventional central buckles (e.g. rigid or flexible central buckles). Furthermore, the effect of BRB yield force, as well as the effectiveness of BRB central buckles combined with viscous dampers, is evaluated using parametric analyses. The results indicate that the BRB central buckle is more effective than other central buckles in reducing both the longitudinal girder displacements and force demands on towers during an earthquake. Furthermore, the combination of BRB central buckles and viscous dampers is a superior option for mitigating the seismic response of long-span suspension bridges.


Sign in / Sign up

Export Citation Format

Share Document