scholarly journals Dual – loop force – displacement mixed control strategy and its application on the quasi – static test

2018 ◽  
Vol 38 (3) ◽  
pp. 296-302
Author(s):  
Cong Zeng ◽  
Bin Wu ◽  
Guoshan Xu ◽  
Zhen Wang ◽  
Tianlin Pan
Keyword(s):  
Control Strategy ◽  
Axial Loading ◽  
Steel Tube ◽  
Control Performance ◽  
Structural Components ◽  
Static Test ◽  
Static Testing ◽  
Mixed Control ◽  
Excellent Control ◽  
Force Displacement

The Quasi-static test is a well-known powerful methodology to evaluate the seismic performance of structural components and systems. One of the most important challenges in the Quasi-static testing is to achieve precise boundary conditions, especially for the axial loading of vertical components. The requirement of synchronized displacement loading and target axial force formed a pair of contradiction. A dual-loop force-displacement mixed control strategy is proposed. The presented approach is successfully verified through the quasi-static testing for a full-scale concrete filled steel tube column. The control targets are achieved with an excellent control performance.

Research on seismic behavior of special-shaped CFST column to H-section steel beam joint

2021 ◽  
pp. 136943322110073
Author(s):  
Yu Cheng ◽  
Yuanlong Yang ◽  
Binyang Li ◽  
Jiepeng Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Joint Stiffness ◽  
Load Ratio ◽  
Element Model ◽  
Steel Tube ◽  
Steel Beam ◽  
Static Test

To investigate the seismic behavior of joint between special-shaped concrete-filled steel tubular (CFST) column and H-section steel beam, a pseudo-static test was carried out on five specimens with scale ratio of 1:2. The investigated factors include stiffening types of steel tube (multi-cell and tensile bar) and connection types (exterior diaphragm and vertical rib). The failure modes, hysteresis curves, skeleton curves, stress distribution, and joint shear deformation of specimens were analyzed to investigate the seismic behaviors of joints. The test results showed the connections of exterior diaphragm and vertical rib have good seismic behavior and can be identified as rigid joint in the frames with bracing system according to Eurocode 3. The joint of special-shaped column with tensile bars have better seismic performance by using through vertical rib connection. Furthermore, a finite element model was established and a parametric analysis with the finite element model was conducted to investigate the influences of following parameters on the joint stiffness: width-to-thickness ratio of column steel tube, beam-to-column linear stiffness ratio, vertical rib dimensions, and axial load ratio of column. Lastly, preliminary design suggestions were proposed.

Controlling chemical dosing for sulfide mitigation in sewer networks using a hybrid automata control strategy

2013 ◽  
Vol 68 (12) ◽  
pp. 2584-2590 ◽  
Author(s):  
Yiqi Liu ◽  
Ramon Ganigué ◽  
Keshab Sharma ◽  
Zhiguo Yuan
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Biological Processes ◽  
Control Performance ◽  
Hybrid Automata ◽  
Sewer Pipe ◽  
Physical Chemical ◽  
Iron Salts ◽  
Pumping Stations ◽  
Sewer Networks

Chemicals such as magnesium hydroxide (Mg(OH)2) and iron salts are widely used to control sulfide-induced corrosion in sewer networks composed of interconnected sewer pipe lines and pumping stations. Chemical dosing control is usually non-automatic and based on experience, thus often resulting in sewage reaching the discharge point receiving inadequate or even no chemical dosing. Moreover, intermittent operation of pumping stations makes traditional control theory inadequate. A hybrid automata-based (HA-based) control method is proposed in this paper to coordinate sewage pumping station operations by considering their states, thereby ensuring suitable chemical concentrations in the network discharge. The performance of the proposed control method was validated through a simulation study of a real sewer network using real sewage flow data. The physical, chemical and biological processes were simulated using the well-established SeweX model. The results suggested that the HA-based control strategy significantly improved chemical dosing control performance and sulfide mitigation in sewer networks, compared to the current common practice.

Strain Analysis of Composite Frame Joints with Double Side Penetrated Diaphragms

2012 ◽  
Vol 166-169 ◽  
pp. 3277-3281
Author(s):  
Min Tong
Keyword(s):  
Stress Distribution ◽  
Strain Analysis ◽  
Steel Tube ◽  
Core Region ◽  
Steel Beam ◽  
Static Test ◽  
The Core ◽  
Composite Frame ◽  
Joint Connection ◽  
New Type

Abstract. Connection joint with penetrated diaphragm, which is better for the stressing state of the welding connection, is a new type joint for the beam and column connection. Static test and pseudo-static test are put to 17 crossing joints. The stress distribution of the steel beam and the penetrated diaphragm are discussed. The experiment shows that the penetrated diaphragm transfer most tension force of the steel beam’s upper flange to the core region of the joint, which could effectively decrease the stress and strain gradient within the connection area of the steel beam’s upper flange and steel tube column. As the result, the shear force of the core region is decreased. The front weld is avoided being surfing great tension. The ductility of the joint and the energy dissipation capacity of the structure are then increased. The type and the size of the penetrated diaphragm show great affection to the stress distribution of steel beam and penetrated diaphragm. The study achievement enriches the joint connection type of the composite structure with concrete- filled steel tube.

Constrained dynamic matrix control strategy for a monitoring system for AGC of hot strip mills

2020 ◽  
Vol 117 (3) ◽  
pp. 308
Author(s):  
Yin Fang-chen ◽  
Yu Liu-Qi
Keyword(s):  
Monitoring System ◽  
Control Strategy ◽  
Smith Predictor ◽  
Model Parameters ◽  
Control Performance ◽  
Dynamic Matrix Control ◽  
Dynamic Matrix ◽  
Model Mismatch ◽  
Hot Strip ◽  
Matrix Control

In the hot strip rolling process, the performance of a monitoring system for automatic gauge control (MN-AGC) is influenced greatly by the model mismatch which is caused by the variation of model parameters values. A constrained dynamic matrix control (CDMC) strategy that includes a prediction model, rolling optimization, and feedback correction was used in the MN-AGC. First, the conventional Smith prediction-based control strategy for the MN-AGC was analyzed. Second, the performance index function and optimal control of the CDMC strategy were determined. Finally, simulations and industrial experiments were conducted. The results showed that both control strategies provided good control performance. When model mismatch occurred, the Smith predictor-based MN-AGC resulted in significant overshoot or even oscillations but the control performance of the CDMC-based MN-AGC was not influenced by changes in the model parameters.

Experimental study on circular steel tube-confined reinforced UHPC columns under axial loading

2021 ◽  
Vol 230 ◽  
pp. 111599
Author(s):  
Jiangang Wei ◽  
Zhitao Xie ◽  
Wei Zhang ◽  
Xia Luo ◽  
Yan Yang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Axial Loading ◽  
Steel Tube ◽  
Circular Steel Tube

Control of Vibration Flow at the Joint of an L-Shaped Frame

2007 ◽  
Author(s):  
C. Mei
Keyword(s):  
Vibration Control ◽  
Control Strategy ◽  
Mechanical Systems ◽  
Structural Elements ◽  
Structural Components ◽  
Structural Element ◽  
Shaped Beam ◽  
Structural Joint ◽  
Structural Joints ◽  
Vibration Problems

There has been an increasing interest in vibration control in recent years. This is due to demands for mechanical structures to be lighter and faster. Lighter and faster structures are more prone to vibrations. Hence, there is an imperative need for practical solutions to vibration problems in complex practical mechanical systems. Regardless of the complexity of a structure, from wave vibration standpoint, it consists of only two basic types of structural components, namely, structural elements and structural joints. In this paper, a control strategy is developed for controlling vibrations flowing from one structural element to another through the structural joint. An L-shaped beam is studied as an example structure. Numerical results are given.

A Switching Scheme for Mixed PZT-Based/Jet Thrusters Control of a Large Flexible Structure

2000 ◽  
Vol 123 (4) ◽  
pp. 722-727 ◽  
Author(s):  
A. Ferrara, ◽  
L. Magnani, and ◽  
R. Scattolini
Keyword(s):  
Energy Consumption ◽  
Control Strategy ◽  
Vibration Suppression ◽  
Space Structure ◽  
Flexible Structure ◽  
Control Performance ◽  
Switching Scheme ◽  
Large Space ◽  
Large Space Structure ◽  
Reduce Energy Consumption

Vibration suppression of a large space structure is achieved by switching between different actuators in order to optimize control performance and to reduce energy consumption. The theoretical properties of the proposed control strategy are reported together with some experimental results.

Experimental Study on the Axial Loading Tests of RC Columns Strengthened with Steel Tube

2012 ◽  
Vol 204-208 ◽  
pp. 2878-2882 ◽  
Author(s):  
Miao Zhou ◽  
Jian Wei Li ◽  
Jing Min Duan
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Axial Loading ◽  
Steel Tube ◽  
Experimental Results ◽  
Engineering Practice ◽  
Rc Columns ◽  
Short Columns ◽  
Loading Tests ◽  
Engineering Staff

This paper carries out a series of experimental study on 6 column specimens, analyses and compares with the different parameters on the axial loading tests of RC columns and RC columns strengthened with steel tube. The experimental results show that the RC columns strengthened with steel tube take full advantage of loading properties of both materials, thus greatly improve the bearing capacity of specimens. With the same wall thickness steel tube, the improving degree of bearing capacity of long columns is bigger than the short columns, and the reinforcement effect is more obvious. The experimental results can offer reference for scientific research and engineering staff, and promote this reinforcement method to be widely used in engineering practice.

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