Research on Bearing Capacity of Column Underpinning Joint of Frame Structure Moving

2011 ◽  
Vol 243-249 ◽  
pp. 426-430 ◽  
Author(s):  
Ai Hua Du ◽  
He Qi Tang
Keyword(s):  
Bearing Capacity ◽  
Mechanical Model ◽  
Frame Structure ◽  
Deep Beam ◽  
Interface Shear ◽  
Joint Stress ◽  
Failure Type ◽  
Before And After ◽  
Interface Slip ◽  
Two Stages

An experiment of sixteen frame column underpinning joints of frame structure moving was introduced, the experiment sample failure phenomena and failure type was obtained. The type was like “deep beam” failure type-“tension bar arch”, and the last failure place occurred on the interface of column and beam. Then, the underpinning joint stress mechanism and failure mode was determined based on the experiment’s conclusion. In addition, the failure course of joint was divided two stages which were before and after interface punching slip by theoretical analysis, for the stage before interface punching slip a space “tension-bar-arch” mechanical model was presented for the underpinning joint, then theoretical bearing capacity equation for this underpinning joint were obtained. At the same time, for the stage of interface after punching slip, the theory of interface shear was put into the analysis of joint, then interface bearing capacity equation was obtained for this stage. At last the height equation was obtained by the analysis of the stage of after interface slip.

Study on Mechanical Mode of Frame Column Underpinning Joint

2011 ◽  
Vol 255-260 ◽  
pp. 624-628 ◽  
Author(s):  
Ai Hua Du ◽  
Xin Zhang
Keyword(s):  
Failure Mode ◽  
Orthogonal Experiment ◽  
Concrete Strength ◽  
Joint Stress ◽  
Shear Span ◽  
Steel Bar ◽  
Moving Beam ◽  
Before And After ◽  
Key Factor ◽  
Two Stages

An orthogonal experiment of sixteen frame column underpinning joints was introduced, experiment was designed by a normal table of “five-factor and four-level”, five factors referred to ratio of shear-span of moving beam, ratio of underpinning beam stirrup steel bar, underpinning beam longitudinal steel bar parameter, concrete strength, and planted reinforcement, in addition every factor had four experiment datum. Then, the underpinning joint stress mechanism and failure mode was determined, based on the experiment the conclusion was drawn that the ratio of shear-span of moving beam was the key factor to the joint failure mode; and the failure course was divided two stages which were before and after interface punching slip by theoretical analysis, for the phase before interface punching slip a space and plane “tension-bar-arch” mechanical model was presented for the underpinning joint, then mechanic analysis was put into the models, and two series theoretical calculation correlations for this underpinning joint were obtained, by comparison with the test result one model and one formula was choose, this theoretical results were agreement with experiments results.

scholarly journals Analysis of Bearing Capacity of Steel-Concrete Composite Beams Considering Interface Slip Effect

2021 ◽  
Vol 719 (2) ◽  
pp. 022036
Author(s):  
Song Yang ◽  
Fan Chen ◽  
Zubin Ai ◽  
Lingyuan Zhou ◽  
Zhensheng Cao
Keyword(s):  
Bearing Capacity ◽  
Composite Beams ◽  
Slip Effect ◽  
Interface Slip

scholarly journals Eco-Friendly Fired Brick Produced from Industrial Ash and Natural Clay: A Study of Waste Reuse

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 877 ◽  
Author(s):  
Neslihan Doğan-Sağlamtimur ◽  
Ahmet Bilgil ◽  
Magdalena Szechyńska-Hebda ◽  
Sławomir Parzych ◽  
Marek Hebda
Keyword(s):  
Compressive Strength ◽  
Bottom Ash ◽  
Unit Weight ◽  
Waste Reuse ◽  
Industrial Solid Waste ◽  
Second Stage ◽  
Before And After ◽  
Fired Bricks ◽  
Two Stages ◽  
And Storage

Bottom ash (BA) is an industrial solid waste formed by the burning of coal. The environmental problems and storage costs caused by this waste increase with every passing day. In this study, the use of BA as an additive (clay substitute) in fired brick production was investigated. The study consisted of two stages. In the first stage, cylinder blocks were produced from clay used in brick production. The second stage was the examination of the experimental substitution of clay with 10, 20, 30 and 40% BA. Samples were fired at 900, 1000, 1100 and 1150 °C to produce fired brick samples. The unit weight, compressive strength (before and after freeze–thawing) and water absorption were analyzed for the samples. The unit weight values decreased in the samples containing BA. The mechanical properties met the conditions prescribed in the relevant standards; i.e., all of the samples fired at 1100 and 1150 °C had a sufficient compressive strength over 20 MPa. The high potential of fired bricks for the construction industry was proved. BA can be used as a clay substitute, while the developed protocol can be used to effectively produce fired bricks.

ANSYS Simply Supported Deep Beams Based on the Study of Mechanical Properties

2013 ◽  
Vol 351-352 ◽  
pp. 782-785
Author(s):  
Yong Bing Liu ◽  
Xiao Zhong Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Mechanical Model ◽  
Work Performance ◽  
Deep Beam ◽  
Analysis Software ◽  
Deep Beams ◽  
Element Analysis ◽  
Simply Supported ◽  
Force Characteristics

Established the mechanical model of simply supported deep beam, calculation and analysis of simple supported deep beams by using finite element analysis software ANSYS, simulated the force characteristics and work performance of the deep beam. Provides the reference for the design and construction of deep beams.

scholarly journals Design of experiments for verification of computational life prediction methods

2019 ◽  
Vol 18 (3) ◽  
pp. 143-154
Author(s):  
O. V. Samsonova ◽  
K. V. Fetisov ◽  
I. V. Karpman ◽  
I. V. Burtseva
Keyword(s):  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Turbine Engines ◽  
Prediction Methods ◽  
Gas Turbine Engines ◽  
Loading Conditions ◽  
Load History ◽  
Strain Behavior ◽  
Before And After ◽  
Two Stages

The failure of heavily loaded rotating parts of aviation gas turbine engines may bring about dangerous consequences. The life of such parts is limited with the use of computational and experimental methods. Computational life prediction methods that are used without carrying out life-cycle tests of engine parts or assemblies should be substantiated experimentally. The best option for verifying the computational methods is to use the results of cyclic tests of model disks. These tests make it possible to reproduce loading conditions and surface conditions that correspond to those of real disks, and the data on the load history and material properties make it possible to simulate stress-strain behavior of disks under test conditions by calculation. This paper shows the process of planning such tests. It is assumed that the tests will be carried out in two stages - before and after the initiation of a low-cycle fatigue crack. A number of criteria are formulated that the geometry of model disks and their loading conditions are to satisfy. Based on these criteria, model disks were designed and the conditions for their testing were selected.

scholarly journals Awareness of COVID-19 Before and After Quarantine Based on Crowdsourced Data From Rabigh City, Saudi Arabia: A Cross-Sectional and Comparative Study

2021 ◽  
Vol 9 ◽  
Author(s):  
Mai Aldhahri ◽  
Rana Alghamdi
Keyword(s):  
Saudi Arabia ◽  
Online Survey ◽  
Control Measures ◽  
Infection Prevention And Control ◽  
Cross Sectional ◽  
Second Stage ◽  
Before And After ◽  
Prevention And Control Measures ◽  
Two Stages ◽  
And Control

Background: Infection prevention and control measures are critical for the prevention of the spread of COVID-19.Aim: In this study, we aimed to measure and evaluate the level of awareness and knowledge of the prevention, symptoms, and transmission control of COVID-19 before and after quarantine among the residents of Rabigh city and adjacent villages in Saudi Arabia.Methods: A cross-sectional online survey was conducted in two stages: the first stage took place before quarantine and the second stage took place after quarantine. The survey was filled out electronically.Results: A total of 448 participants responded and filled out the questionnaires. Females (73.70%) formed the largest number of participants for both stages. The majority of the participants were <30 years old (50.90%) and had a high education level in various sectors and levels (97.1%). It was noticeable that during the first stage, the participants' awareness of COVID-19 symptoms was not very high: 13.62% did not know about the symptoms. However, by the second stage, awareness about symptoms had increased (9.6%).Conclusion: The residents of Rabigh city and the surrounding villages had good levels of knowledge about COVID-19.

Base-Isolated Multi-Storey Reinforced Concrete Frame Structure Modal Analysis

2012 ◽  
Vol 204-208 ◽  
pp. 869-871
Author(s):  
Cai Hua Wang ◽  
Hui Jian Li ◽  
Jian Feng Wu
Keyword(s):  
Reinforced Concrete ◽  
Modal Analysis ◽  
Seismic Isolation ◽  
Base Isolation ◽  
Frame Structure ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Reinforced Concrete Frame Structure ◽  
Before And After ◽  
Isolation Device

The multi-storey reinforced concrete frame structure used lead rubber pad as the base isolation device. The paper had modal analysis of base-isolated multi-storey reinforced concrete frame structure using the ANSYS software. Comparing the frequency and vibration mode before and after isolation under El-Centro wave, It concluded the leader rubber pad have seismic isolation effect for multi-storey reinforced concrete frame structure .

scholarly journals Análisis de Confiabilidad en Subestaciones Eléctricas Tipo Maniobra Implementando el Transformador de Tensión con Núcleo de Potencia

Ingeniería ◽  
2017 ◽  
Vol 22 (1) ◽  
pp. 140
Author(s):  
Diego Ernesto Viteri ◽  
César Andrés Garzón Bustos ◽  
Eider Alexander Narvaez Cubillos
Keyword(s):  
Current System ◽  
Lower Probability ◽  
Voltage Transformer ◽  
Collaborative Project ◽  
Energy Company ◽  
Before And After ◽  
Transformer Power ◽  
Electricity Power ◽  
Two Stages ◽  
Auxiliary Services

Context: It is intended to conduct a technical study of a voltage transformer power core, used for the supply of the auxiliary services of a maneuver type substation, hoping to mitigate the possibility of losing the continuous electricity power supply and likewise reducing the dependency with the external supplier. This is a result of a collaborative project between the Bogota Energy Company and the Universidad Distrital Francisco Jose de Caldas.Method: The study consists of two stages, the first one is an analysis of reliability of the substation auxiliary systems, carried out in three scenarios: before and after use of the transformer and using a unique generator for auxiliary services. The second one is simulation using the ATP software to verify the behavior of the equipment in transient state.Results: The reliability of auxiliary services increased after the equipment has been installed, as the failure rate went from 0.31 [failure/year] with the current system, to become 0.0025 [failure/year].Conclusions: The implementation of transformer is suitable for substations that do not have a reliable power system auxiliary services as it makes the substation auto dependent. Implement this system in Colombia would get a big increase in the reliability of the auxiliary services in maneuver type substations and therefore a lower probability of loss.

scholarly journals Damage Constitutive Model and Mechanical Performance Deterioration of Concrete under Sulfate Environment

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Peng Liu ◽  
Ying Chen ◽  
Zhiwu Yu ◽  
Zhaohui Lu
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Elasticity Modulus ◽  
Mechanical Performance ◽  
Sulfate Solution ◽  
Concrete Surface ◽  
Ultimate Bearing Capacity ◽  
Stress Strain ◽  
Before And After ◽  
Relationship Model

The effects of erosion mode, erosion age, and concentration of sulfate solution on mechanical properties of concrete were investigated. The dimensionless relationship model of the stress-strain of concrete on the basis of randomness was proposed. The variation of the elasticity modulus and Poisson’s ratio of the concrete surface attacked by sulfate was studied, and a novel method of using a superficial parameter to characterize the performance change of the concrete surface was recommended. The results showed that the dimensionless relationship model of stress-strain of concrete could be used to represent the variations of mechanical properties of concrete. The differences of load-displacement of concrete before and after sulfate attack were reflected as the change of curve’s slope and ultimate bearing capacity, and the slope of a straight section of the lateral and longitudinal strain curves of concrete surface also varied. The increment rates of ultimate bearing capacity of concrete attacked by 1% and saturated sulfate solution were about 30% and 10%, respectively. However, the decreasing ratio of the ultimate bearing capacity of concrete attacked by saturated sulfate solution was approximately 25%. The damage factor of the elasticity modulus of the concrete surface of C20 and C40 was 0.185 and −0.19, respectively. The obtained results could provide a support for investigating the variations of stress-strain relationship and mechanical performance of concrete under a sulfate environment.

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