scholarly journals Numerical Investigation of Residual Displacement of Rocking Self-Centering Columns Under Cyclic Loading

2021 ◽  
Author(s):  
Yan Shi ◽  
zhengwu zhong ◽  
Zhichao Zhang ◽  
Jianping Han ◽  
Hu Cheng
Keyword(s):  
Quantitative Analysis ◽  
Energy Dissipation ◽  
Parametric Analysis ◽  
The Self ◽  
Design Parameters ◽  
Residual Displacement ◽  
Residual Drift ◽  
Predictive Regression ◽  
Upper Limit ◽  
Simplified Formula

Abstract Well-designed rocking self-centering (RSC) columns are capable of achieving small residual displacement. However, few studies conducted the quantitative analysis for the residual displacement of RSC columns. The residual displacement is the product of the struggle between the self-centering (SC) capacity and the energy dissipation (ED) capacity. In this study, a SC factor and an ED parameter were defined to reflect the SC and ED capacity of the RSC column, respectively. The influence of eight common design parameters on the SC factor and the ED parameter was explored using factorial analysis. Parametric analysis was performed to investigate the tendency of the SC factor and the ED parameter with the increase of maximum drift. According to the results of the parametric analysis, the effect of the SC factor and the ED parameter on the distribution of the residual drift was researched statistically. A simplified formula was proposed to calculate the upper limit of the residual drift. What is more, a set of predictive regression formulas was established to estimate the actual residual drift, these regression formulas have an applicable condition that the ED parameter should be larger than 0.75. When the ED parameter was less than 0.75, the residual drift is approximate to zero.

scholarly journals Influencing factors of residual drifts of precast segmental bridge columns with energy dissipation bars

2018 ◽  
Vol 22 (1) ◽  
pp. 126-140 ◽  
Author(s):  
Zhong-Kui Cai ◽  
Zheng Zhou ◽  
Zhenyu Wang
Keyword(s):  
Energy Dissipation ◽  
Influencing Factors ◽  
Design Procedure ◽  
Bridge Columns ◽  
Hysteretic Behavior ◽  
Design Parameters ◽  
Seismic Capacity ◽  
Residual Drift ◽  
Bridge Column ◽  
Segmental Bridge

The energy dissipation bar has been proven to be an effective way to improve the lateral strength and the seismic capacity of the precast segmental bridge column. To date, however, investigations on how the main design parameters affect the residual drift of such bridge columns are quite limited. Focusing on this research gap, a novel numerical simulation method was proposed in this article to investigate the influencing factors of residual drift of precast segmental bridge columns with energy dissipation bars. First, the refined fiber element model was developed based on the OpenSees software package, considering the bond slip phenomenon at the column end and the boundary condition at the interface between the two adjacent segments. Then, the proposed numerical model was validated by comparing the simulated hysteretic behavior of the precast segmental bridge columns with available experimental data. After that, cyclic analyses were performed on 288 precast segmental bridge column models with different design parameters. Four important influencing factors were investigated, including the post-tensioning force, gravity load, energy dissipation bar ratio, and shear span ratio. According to the analysis results, some suggestions were provided for the practical design procedure of the energy dissipation bar reinforced precast segmental bridge columns.

Evaluating Self-Centering Behavior of Unbonded Prestressed Bridge Columns Using a New Performance Index Based on Quasi-Static Analysis

2018 ◽  
Vol 12 (01) ◽  
pp. 1850001 ◽  
Author(s):  
Xiaoxian Liu ◽  
Jianzhong Li ◽  
H. H. Tsang ◽  
John L. Wilson
Keyword(s):  
Performance Index ◽  
Parametric Analysis ◽  
Hysteretic Behavior ◽  
Index Formula ◽  
Design Parameters ◽  
Seismic Load ◽  
Longitudinal Reinforcement ◽  
Reinforced Concrete Column ◽  
Residual Displacement ◽  
Prestressing Force

In order to fulfill post-earthquake operational requirements, in recent years, there has been an increasing interest in developing self-centering structural systems, where self-centering elements are used with combinations of energy dissipation elements in parallel. It was demonstrated experimentally and numerically that such systems exhibit robust flag-shape hysteretic behavior under seismic load. A new performance index for evaluating self-centering behavior of the bridge column is developed in this paper based on the flag-shape hysteresis and the index can be obtained conveniently. Parametric analysis was carried out to investigate the effects of different parameters on the seismic response of a SDOF system. The results show that the residual displacement decreases as the new performance index increases and the residual displacement is negligible when the performance index [Formula: see text] exceeds unity (1.0). Furthermore, parametric analysis was conducted to investigate the effects of design parameters on the self-centering behavior of an unbonded pre-stresed reinforced concrete column (UBPS column). The design parameters include the prestressing force, the bonded longitudinal reinforcement ratio and the area of unbonded strands. Results show that either increasing the prestressing force or decreasing the amount of longitudinal reinforcement can result in smaller residual displacement and a higher value of the new index.

scholarly journals A New Approach for Design Optimization and Parametric Analysis of Symmetric Compound Parabolic Concentrator for Photovoltaic Applications

2021 ◽  
Vol 13 (9) ◽  
pp. 4606
Author(s):  
Faisal Masood ◽  
Perumal Nallagownden ◽  
Irraivan Elamvazuthi ◽  
Javed Akhter ◽  
Mohammad Azad Alam
Keyword(s):  
Parametric Analysis ◽  
Concentration Ratio ◽  
Synergistic Effects ◽  
Geometric Optimization ◽  
Design Parameters ◽  
Imaging Device ◽  
Compound Parabolic Concentrator ◽  
Photovoltaic Applications ◽  
Half Angle ◽  
The Impact

A compound parabolic concentrator (CPC) is a non-imaging device generally used in PV, thermal, or PV/thermal hybrid systems for the concentration of solar radiation on the target surface. This paper presents the geometric design, statistical modeling, parametric analysis, and geometric optimization of a two-dimensional low concentration symmetric compound parabolic concentrator for potential use in building-integrated and rooftop photovoltaic applications. The CPC was initially designed for a concentration ratio of “2×” and an acceptance half-angle of 30°. A MATLAB code was developed in house to provoke the CPC reflector’s profile. The height, aperture width, and concentration ratios were computed for different acceptance half-angles and receiver widths. The interdependence of optical concentration ratio and acceptance half-angle was demonstrated for a wide span of acceptance half-angles. The impact of the truncation ratio on the geometric parameters was investigated to identify the optimum truncation position. The profile of truncated CPC for different truncation positions was compared with full CPC. A detailed statistical analysis was performed to analyze the synergistic effects of independent design parameters on the responses using the response surface modeling approach. A set of optimized design parameters was obtained by establishing specified optimization criteria. A 50% truncated CPC with an acceptance half-angle of 21.58° and receiver width of 193.98 mm resulted in optimum geometric dimensions.

Automated simulation techniques for uncovering high-performance bioinspired cellular structures under blast loads

2021 ◽  
pp. 109963622110204
Author(s):  
Abdallah Ghazlan ◽  
Tuan Ngo ◽  
Tay Son Le ◽  
Tu Van Le
Keyword(s):  
Energy Dissipation ◽  
Trabecular Bone ◽  
Reaction Force ◽  
Blast Loading ◽  
Performance Criteria ◽  
Superior Performance ◽  
Cellular Structures ◽  
Design Parameters ◽  
Engineering Practice ◽  
Automated Simulation

Trabecular bone possesses a complex hierarchical structure of plate- and strut-like elements, which is analogous to structural systems encountered in engineering practice. In this work, key structural features of trabecular bone are mimicked to uncover effective energy dissipation mechanisms under blast loading. To this end, several key design parameters were identified to develop a bone-like unit cell. A computer script was then developed to automatically generate bone-like finite element models with many combinations of these design parameters, which were simulated under blast loading. The optimal structure was identified and its performance was benchmarked against traditional engineered cellular structures, including those with hexagonal, re-entrant and square cellular geometries. The bone-like structure showed superior performance over its engineered counterparts using the peak transmitted reaction force and energy dissipation as the key performance criteria.

scholarly journals Kaolin based protective barrier in municipal landfills against adverse chemo-mechanical loadings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Partha Das ◽  
Tadikonda Venkata Bharat
Keyword(s):  
Ionic Strength ◽  
High Ionic Strength ◽  
The Self ◽  
Design Parameters ◽  
Layered System ◽  
Geosynthetic Clay Liners ◽  
Clay Liners ◽  
Landfill Liner ◽  
First Time ◽  
Applied Stresses

AbstractIn this work, we assess the self-sealing and swelling ability of the compacted granular bentonite (GB) under an inorganic salt environment and induced overburden stresses from the landfill waste. The laboratory permeation tests with high ionic strength salt solutions reveal that the GB fails to seal and exhibits a significant mechanical collapse under different applied stresses. The applicability of GB in the form of geosynthetic clay liners as the bottom liner facilities in landfills that produce high ionic strength salt leachates, therefore, remains a serious concern. We propose an additional barrier system based on kaolin, for the first time, to address this problem. The proposed kaolin-GB layered system performs satisfactorily in terms of its sealing and swelling ability even in adverse saline conditions and low overburden stresses. The kaolin improves the osmotic efficiency of the self and also helps the underlying GB layer to seal the inter-granular voids. The estimated design parameters by through-diffusion test suggest that the kaolin-GB layered system effectively attenuates the permeant flux and suitable as a landfill liner.

Quantitative Analysis of the Self-Assembly Strategies of Intermediate Filaments from Tetrameric Vimentin

2012 ◽  
Vol 9 (3) ◽  
pp. 885-898 ◽  
Author(s):  
E. Czeizler ◽  
A. Mizera ◽  
E. Czeizler ◽  
R-J Back ◽  
J. E. Eriksson ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Intermediate Filaments ◽  
Self Assembly ◽  
The Self

Synthesis of the internal parallel cam mechanism

1998 ◽  
Vol 212 (7) ◽  
pp. 577-585 ◽  
Author(s):  
M Nishioka ◽  
T Nishimura
Keyword(s):  
Parametric Analysis ◽  
Parallel Mechanism ◽  
Design Parameters ◽  
Cam Mechanism ◽  
Pressure Angle

Parallel cam mechanisms have been studied in different ways. In this paper, a parametric formulation which can cover every configuration of the parallel cam mechanism is derived. As a result of parametric analysis, a new, last mechanism was found. This cam is essentially an internal cam mechanism. Based on the assumption of an equally distributed roller follower, the basic configurations of the mechanism are derived from both the pressure angle and the undercutting constraints. As a result, the possible number of rollers per spider plate is two. Thus the feasible area of the design parameters of the mechanisms are obtained. The advantages of the mechanism over the conventional parallel mechanism are the saving of space and a larger angular stroke of output.

PRELIMINARY STUDY ON NOVEL BEAM-TO-COLUMN CONNECTION BASED ON SMA PLATE

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Michael CH Yam ◽  
Ke Ke ◽  
Ping Zhang ◽  
Qingyang Zhao
Keyword(s):  
Friction Coefficient ◽  
Energy Dissipation ◽  
Numerical Study ◽  
Numerical Models ◽  
Numerical Technique ◽  
The Self ◽  
Hysteretic Behavior ◽  
The Novel ◽  
Energy Dissipation Capacity ◽  
Preliminary Study

A novel beam-to-column connection equipped with shape memory alloy (SMA) plates has been proposed to realize resilient performance under low-to-medium seismic actions. In this conference paper, the detailed 3D numerical technique calibrated by the previous paper is adopted to examine the hysteretic behavior of the novel connection. A parametric study covering a reasonable range of parameters including the thickness of the SMA plate, friction coefficient between SMA plate and beam flange and pre-load of the bolt was carried out and the influence of the parameters was characterized. In addition, the effect of the SMA Belleville washer on the connection performance was also studied. The results of the numerical study showed that the initial connection stiffness and the energy-dissipation capacity of the novel connection can be enhanced with the increase of the thickness of the SMA plate. In addition, the initial connection stiffness and energy-dissipation behavior of the novel connection can be improved by increasing the friction coefficient or pre-load of bolts, whereas the increased friction level could compromise the self-centering behavior of the connection. The hysteretic curves of the numerical models of the connection also implied that the SMA washers may contribute to optimizing the connection behavior by increasing the connection stiffness and energy-dissipation capacity without sacrificing the self-centering behavior.

Estimation of Seismic Energy Dissipation for Steel Slit Shear Walls Considering Out-of-Plane Buckling

2021 ◽  
Author(s):  
Yiming Ma ◽  
Liusheng He ◽  
Ming Li
Keyword(s):  
Energy Dissipation ◽  
Shear Walls ◽  
Seismic Energy ◽  
Thickness Ratio ◽  
Design Parameters ◽  
Test Results ◽  
Loading Test ◽  
Aspect Ratios ◽  
Out Of Plane ◽  
Energy Dissipation Capacity

Steel slit shear walls (SSSWs), made by cutting slits in steel plates, are increasingly adopted in seismic design of buildings for energy dissipation. This paper estimates the seismic energy dissipation capacity of SSSWs considering out-of-plane buckling. In the experimental study, three SSSW specimens were designed with different width-thickness ratios and aspect ratios and tested under quasi-static cyclic loading. Test results showed that the width-thickness ratio of the links dominated the occurrence of out-of-plane buckling, which produced pinching in the hysteresis and thus reduced the energy dissipation capacity. Out-of-plane buckling occurred earlier for the links with a larger width-thickness ratio, and vice versa. Refined finite element model was built for the SSSW specimens, and validated by the test results. The concept of average pinching parameter was proposed to quantify the degree of pinching in the hysteresis. Through the parametric analysis, an equation was derived to estimate the average pinching parameter of the SSSWs with different design parameters. A new method for estimating the energy dissipation of the SSSWs considering out-of-plane buckling was proposed, by which the predicted energy dissipation agreed well with the test results.

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