scholarly journals Simplified moment-curvature relationship in analytical form for circular RC sections

2018 ◽  
Vol 51 (3) ◽  
pp. 145-158 ◽  
Author(s):  
Roberto Gentile ◽  
Francesco Porco ◽  
Domenico Raffaele ◽  
Giuseppina Uva
Keyword(s):  
Plastic Hinge ◽  
Regional Scale ◽  
Analytical Form ◽  
Order Effects ◽  
Lap Splice ◽  
Characteristic Points ◽  
The Moment ◽  
Fixed End ◽  
Relationship Of ◽  
Plastic Hinge Length

The behaviour of regular multi-span simply-supported bridges is strongly dependent on the behaviour of its piers. The response of a pier is governed, in general, by different mechanisms: flexure, shear, second order effects, lap-splice of longitudinal bars or their buckling. The flexural behaviour is an important part of the problem, and it can be characterised through the equivalent plastic hinge length and the Moment-Curvature law of the fixed end. In this paper, a procedure to calculate the Moment-Curvature relationship of circular RC sections is proposed which is based on defining the position of few characteristic points. The analytical formulation is based on adjusted polynomial functions fitted on a database of fibre-based analyses. The proposed solution is based on three parameters: dimensionless axial force, mechanical ratio of longitudinal reinforcement, geometrical ratio of transverse reinforcement. A benchmark case is presented to compare the solution to a FEM non-linear analysis. Even if it is based on few input data, this solution allows to have good indicators on the material performances (e.g. yielding, spalling, etc). For these reasons, the proposed approach is deemed to be particularly effective in performing quick yet accurate mechanics-based regional-scale assessment of bridges.

Constitutive Relationship of FRP Reinforced Column Plastic Hinge Zone Based on Pushover Analysis

2013 ◽  
Vol 351-352 ◽  
pp. 699-703
Author(s):  
Guo Hua Sheng ◽  
Fu Sheng Zhu ◽  
Jun Zhang ◽  
Guang Shan Zhu
Keyword(s):  
Plastic Hinge ◽  
Pushover Analysis ◽  
Constitutive Relationship ◽  
Whole Process ◽  
Modes Of Failure ◽  
Flexural Member ◽  
Hinge Zone ◽  
Ultimate Moment ◽  
The Moment ◽  
Relationship Of

The formation and development of plastic hinge is the basis of the whole process of FRP reinforced concrete eccentricity compression and flexural member nonlinear analysis. The moment-rotation relationship of FRP reinforced rectangular column plastic hinge zone was studied. Its yield and ultimate moment formulas were proposed. The specific values of the moment and rotation were discussed in different modes of failure, retrofitting methods as well as FRP types. A constitutive relationship of FRP reinforced rectangular column plastic hinge zone was established. Based on the constitutive relationship, a pushover analysis of the numerical model is conducted, and the feasibility of its application in Etabs software through cases is verified.

scholarly journals Moment-Rotation Behavior of Force-Based Plastic Hinge Elements

2013 ◽  
Vol 29 (2) ◽  
pp. 597-607 ◽  
Author(s):  
Michael H. Scott ◽  
Keri L. Ryan
Keyword(s):  
Strain Hardening ◽  
Carrying Capacity ◽  
Loading Condition ◽  
Plastic Hinge ◽  
Lateral Load ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
The Moment ◽  
Plastic Hinge Length ◽  
Unique Relationship

The moment-rotation behavior of force-based frame elements is expressed as a function of plastic hinge length and moment-curvature parameters for two types of plastic hinge integration under the representative loading condition of antisymmetric bending. For modified Gauss-Radau hinge integration, there is a unique relationship between the resulting moment-rotation hardening ratio and parameters defining the plastic hinge length and moment-curvature hardening ratio. For two-point Gauss-Radau hinge integration, the spread of yielding across the hinge regions leads to a multilinear moment-rotation response, for which a secant approximation of the hardening stiffness is directed to a target plastic rotation. An example application demonstrates that significantly unconservative assessments of lateral load-carrying capacity can be attained if modeling parameters for plastic hinge length and moment-curvature strain hardening are not calibrated to account for the discrepancy between moment-curvature and moment-rotation behavior of an element.

Evaluation of load–deformation behavior of reinforced concrete shear walls with continuous or lap-spliced bars in plastic hinge zone

2018 ◽  
Vol 22 (3) ◽  
pp. 722-736 ◽  
Author(s):  
Qing Zhi ◽  
Binbin Zhou ◽  
Zhangfeng Zhu ◽  
Zhengxing Guo
Keyword(s):  
Reinforced Concrete ◽  
Deformation Behavior ◽  
Plastic Hinge ◽  
Shear Walls ◽  
Analysis Procedure ◽  
Bond Slip ◽  
Lap Splices ◽  
Lap Splice ◽  
Hinge Zone ◽  
Plastic Hinge Length

This article presents an analysis procedure for evaluation of load–deformation behavior of reinforced concrete shear walls with continuous or lap-spliced bar connections in plastic hinge zones under horizontal loads. For the shear walls with continuous bars, the lateral deformations caused by flexure, shear, and reinforcement slip are evaluated by considering their interaction. The flexural deformation is calculated by conventional fiber model. The shear mechanism is based on modified compression field theory with a softened smeared cracked reinforced concrete membrane element. Both the flexural and shear deformations are estimated separately in the plastic hinge and non-plastic hinge regions. In addition, an approach is proposed for analysis of plastic hinge length based on fracture energies of materials. For the shear walls with lap-spliced bars, due to its complicated behavior and mechanism, a simple way to deal with the lap splice is proposed. The equations regarding bond-slip of the lap splice with minimum spliced length are established and the stress and strain states of lap splices with different spliced lengths are analyzed on the basis of equilibrium of forces with a mean bond stress model. Finally, the validity of the proposed analysis procedure is confirmed by comparing the analytical results with previous experimental data.

scholarly journals Numerical Modelling of Reinforced Concrete Slender Walls Subjected to Coupled Axial Tension–Flexure

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Xiaowei Cheng ◽  
Haoyou Zhang
Keyword(s):  
Reinforced Concrete ◽  
Plastic Hinge ◽  
Element Model ◽  
Lateral Loading ◽  
Design Parameters ◽  
Seismic Behaviour ◽  
High Rise ◽  
Ultimate Deformation ◽  
Axial Tension ◽  
Plastic Hinge Length

AbstractUnder strong earthquakes, reinforced concrete (RC) walls in high-rise buildings, particularly in wall piers that form part of a coupled or core wall system, may experience coupled axial tension–flexure loading. In this study, a detailed finite element model was developed in VecTor2 to provide an effective tool for the further investigation of the seismic behaviour of RC walls subjected to axial tension and cyclic lateral loading. The model was verified using experimental data from recent RC wall tests under axial tension and cyclic lateral loading, and results showed that the model can accurately capture the overall response of RC walls. Additional analyses were conducted using the developed model to investigate the effect of key design parameters on the peak strength, ultimate deformation capacity and plastic hinge length of RC walls under axial tension and cyclic lateral loading. On the basis of the analysis results, useful information were provided when designing or assessing the seismic behaviour of RC slender walls under coupled axial tension–flexure loading.

Experimental study of moment carrying behavior of typical Tibetan timber beam-column joints

2021 ◽  
pp. 136943322110015
Author(s):  
Ting Guo ◽  
Na Yang ◽  
Huichun Yan ◽  
Fan Bai
Keyword(s):  
Bending Moment ◽  
Structural Performance ◽  
Test Results ◽  
Timber Beam ◽  
Rotational Stiffness ◽  
Trilinear Model ◽  
Column Joint ◽  
Loading Tests ◽  
The Moment ◽  
Relationship Of

This study aimed to investigate the moment carrying behavior of typical Tibetan timber beam-column joints under monotonic vertical static load and also evaluate the influence of length ratio of Gongmu to beam (LRGB) and dowels layout on the structural performance of the joint. Six full-scale specimens were fabricated with same construction but different Gongmu length and dowels position. The moment carrying performance of beam-column joints in terms of failure mode, moment resistance, and rotational stiffness of joints were obtained via monotonic loading tests. Test results indicated that all joints are characterized by compressive failure perpendicular to grain of Ludou. Additionally, it was found that greater LRGB leads to greater initial rotational stiffness and maximum moment of the joint by an increase of restraint length for beam end; however, offsetting dowels toward column resulted smaller stiffness and ultimate bending moment of joints, particularly, offsetting Beam-Gongmu dowels toward column changed the moment-rotation curve pattern of the beam-column joint, accompanied by a hardening stiffness at last phase. Furthermore, a simplified trilinear model was proposed to represent the moment-rotation relationship of the typical Tibetan timber beam-column joint.

Dynamic Modeling of the Torsional Vibration of the Slewing Mechanism of a Hydraulic Excavator

2012 ◽  
Vol 253-255 ◽  
pp. 2102-2106 ◽  
Author(s):  
Xu Juan Yang ◽  
Zong Hua Wu ◽  
Zhao Jun Li ◽  
Gan Wei Cai
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Planetary Gear ◽  
Moment Of Inertia ◽  
Hydraulic Excavator ◽  
Planetary Gear Trains ◽  
Vibration Model ◽  
Gear Trains ◽  
The Moment ◽  
Relationship Of

A torsional vibration model of the slewing mechanism of a hydraulic excavator is developed to predict its free vibration characteristics with consideration of many fundamental factors, such as the mesh stiffness of gear pairs, the coupling relationship of a two stage planetary gear trains and the variety of moment of inertia of the input end caused by the motion of work equipment. The natural frequencies are solved using the corresponding eigenvalue problem. Taking the moment of inertia of the input end for example to illustrate the relationship between the natural frequencies of the slewing mechanism and its parameters, based on the simulation results, just the first order frequency varies significantly with the moment of inertia of the input end of the slewing mechanism.

Interpersonal Conflicts in the Relationship of Twins

1998 ◽  
Vol 47 (3-4) ◽  
pp. 153-160
Author(s):  
S. A. Gruszewska
Keyword(s):  
Social Life ◽  
Interpersonal Conflict ◽  
The Other ◽  
Psychological Space ◽  
Interpersonal Conflicts ◽  
Educational Methods ◽  
The Moment ◽  
Relationship Of ◽  
The Relationship

AbstractTaking into consideration two facts: that the structure of social life forces twins to part and that the presented roles in a pair are not equal, (one of the twins plays the role of a leader (L) and the other, the subordinate (P.)), one can ask the question — what meaning does the moment of parting have and what are its consequences?In order to do that, a survey was conducted, (a sample of 31 pairs of twins above the age of 30), in which every pair was asked the question: “Which one of you made the decision about parting?” The answer had two options: A – I, B – brother/sister. Out of 31 pairs of twins, 16 pairs chose the variant different from his brother or sister – that is A, B, admitting that the interpersonal conflict was the result of the parting. In 7 pairs, both twins chose the B variant – they withdrew from the conflict; and in 8 pairs they chose the A variant – looking for a compromise as the means of agreement.When analyzing the results of the survey, we can state the following:– in the relationship of twins, there is an interpersonal conflict;– the decision about parting is difficult with prevalent feelings of sadness and sorrow;– after parting, at least one of the twins has problems with preserving his identity and integrity of psychological space.Since the moment of parting is necessary and difficult, specialists and mainly parents are required to consciously change their position towards the relationship of twins. It has to be the result of applied educational methods which aim at creating subjectivity and equality of each of the twins before the moment of parting.

scholarly journals Metabolic markers and oxidative stress in children’s obesity pathogenesis

2020 ◽  
Vol 65 (1) ◽  
pp. 22-29
Author(s):  
O. V. Povarova ◽  
E. A. Gorodetskaya ◽  
E. I. Kalenikova ◽  
O. S. Medvedev
Keyword(s):  
Oxidative Stress ◽  
Adipose Tissue ◽  
Chronic Inflammation ◽  
Metabolic Disorders ◽  
Mineral Metabolism ◽  
Related Factors ◽  
Metabolic Markers ◽  
Hormonal Function ◽  
The Moment ◽  
Relationship Of

The article presents a modern view of obesity as a chronic inflammation of adipose tissue. Obesity is accompanied by metabolic changes in lipid, protein, carbohydrate, mineral metabolism and disorders in the hormonal function of adipose tissue as an endo- and paracrine organ. At the moment, there are searched the biochemical markers of metabolic disorders of obesity. The obesity-related factors (hyperglycemia, increased lipid levels, insulin resistance, chronic inflammation, hyperleptinemia, endothelial dysfunction, impaired respiratory function of mitochondria, minerals and microelements deficiency) form and increase oxidative stress making it an integral component of the pathogenesis of obesity and possible complications. Given the important role of Q10 coenzyme in antioxidant tissue protection, the authors discuss the relationship of obesity and metabolic disorders to the endogenous levels of Q10 coenzyme and its possible use for pharmacological correction.

Investigation of Plastic Hinge Length in Reinforced Concrete Columns on Column Behavior

2017 ◽  
Vol 21 ◽  
pp. 45-49
Author(s):  
Mehmet Kamanli ◽  
Alptug Unal
Keyword(s):  
Reinforced Concrete ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Concrete Columns ◽  
Analysis Program ◽  
Reinforced Concrete Buildings ◽  
Reinforced Concrete Columns ◽  
Concrete Buildings ◽  
Horizontal Stability ◽  
Plastic Hinge Length

In reinforced concrete buildings in case of a possible earthquake, the buildings slamp as they lost their horizontal stability because of hinging of column ends. The assumptions for plastic hinge lengths are present during project stage of reinforced concrete buildings. According to Turkish Earthquake Regulations, although plastic hinge length is determined to be 0.5h, it's known that plastic hinge length is determined via various formulas in some other regulations all over the world. In reinforced concrete columns, it's necessary to indicate the effect of plastic hinge length on the column behavior. For this purpose, pushover analysis of 5 column samples having different plastic hinge lengths was performed with non-linear analysis program. As a result of pushover analysis, situations of plastic hinges formed in columns and their load-displacement curves were determined. The graphs and the data were compared and the results were discussed.

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