scholarly journals Preliminary Collapse Simulation of a Reinforced Concrete Flat Plate Substructure Using Spring Connection Modelling

2014 ◽  
Vol 638-640 ◽  
pp. 1445-1448
Author(s):  
Hui Zhong Xue ◽  
Hong Guan ◽  
Yi Li
Keyword(s):  
Reinforced Concrete ◽  
Flat Plate ◽  
Shear Failure ◽  
Progressive Collapse ◽  
Numerical Approach ◽  
Punching Shear ◽  
Structural Behavior ◽  
Steel Bars ◽  
Collapse Behavior ◽  
Shear Spring

To investigate progressive collapse behavior of reinforced concrete (RC) flat plate structures, a reliable and efficient numerical approach is developed in this study using spring connection modelling. This connection unit aims to simulate complicate punching shear behavior at critical regions surrounding the columns. Five springs are used as the connection elements: two for flexural and integrity steel bars and three for concrete contributions. The flexural and integrity steel bars embedded in the columns are modeled explicitly, which enables the model to present the structural behavior post punching shear failure. Bending and shear actions are represented by two concrete springs. The third concrete spring is assigned axial action property to restrain two end nodes of the connection on the model. In particular, the punching shear spring controls the connection unit when punching shear failure occurs. To apply the connection unit, the regions of slab-column connections are partitioned from the slab regions according to the critical shear surfaces. Then the connection unit links two corresponding nodes on the two edges formed from the partition. A physical experiment of a RC flat plate substructure under progressive collapse is simulated. Result comparison demonstrates that the numerical model has the capability to capture the structural behavior in progressive collapse. However, further improvement of the modelling technique is necessary to enhance numerical accuracy.

scholarly journals Improvement of bearing performance on exterior steel beam-reinforced concrete column joints with steel column

2018 ◽  
Author(s):  
Shinya Nakaue ◽  
Yasushi Nishimura
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Maximum Strength ◽  
Punching Shear ◽  
Steel Beam ◽  
Transverse Reinforcement ◽  
Concrete Column ◽  
Bearing Failure ◽  
Reinforced Concrete Column ◽  
Steel Column

To improve the bearing failure behavior of the exterior steel beam-reinforced concrete column joints composed of reinforced concrete columns, joint details using steel column was proposed. Steel column was attached to the lower flanges at right angles to the steel flange. The objective of this study is to clarify the effectiveness of proposed joint details experimentally and theoretically. To clarify the influence of steel column on the bearing failure of the joint, seven T-shaped subassemblages were tested under reversed cyclic loading. All specimens had the same cross sections of the steel beam. The experimental variables were the embedded length of the steel column, whether there is the end plate at the tip of the embedded steel column, and, the arrangement of transverse reinforcement ratio surrounding the steel column. The following remarks can be drawn from the test results. 1) In case of the specimen with a short embedded length of the steel column, the punching shear failure on the upper surface of the steel beam flange was remarkable when the maximum strength was reached. However, in the specimen with long embedded length of steel column, it was not observed the punching shear failure. 2) The maximum strength increased with the embedded length of the steel column. Further, the maximum strength of the specimen with the embedded length of three times of the steel column depths is subjected to bending yield strength of the steel column. 3) It was shown that the transverse reinforcement to surround the steel column and the end plate were necessary to improve the bearing failure of the joint. 

scholarly journals PUNCHING SHEAR STRENGTHS OF HYBRID REINFORCED CONCRETE FLAT PLATE SLABS

2018 ◽  
Vol 2018 (04) ◽  
pp. 101-115
Author(s):  
Suha Rasheed Abass ◽  
◽  
Haitham Jameel Abd ◽  
Keyword(s):  
Reinforced Concrete ◽  
Flat Plate ◽  
Punching Shear

Analysis of Shear-critical reinforced concrete columns under variable axial load

2022 ◽  
pp. 1-24
Author(s):  
Dimitrios K. Zimos ◽  
Panagiotis E. Mergos ◽  
Vassilis K. Papanikolaou ◽  
Andreas J. Kappos
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Shear Failure ◽  
Progressive Collapse ◽  
Full Range ◽  
Element Model ◽  
Independent Verification ◽  
Lateral Response ◽  
Proposed Model ◽  
Compressive Axial Load

Older existing reinforced concrete (R/C) frame structures often contain shear-dominated vertical structural elements, which can experience loss of axial load-bearing capacity after a shear failure, hence initiating progressive collapse. An experimental investigation previously reported by the authors focused on the effect of increasing compressive axial load on the non-linear post-peak lateral response of shear, and flexure-shear, critical R/C columns. These results and findings are used here to verify key assumptions of a finite element model previously proposed by the authors, which is able to capture the full-range response of shear-dominated R/C columns up to the onset of axial failure. Additionally, numerically predicted responses using the proposed model are compared with the experimental ones of the tested column specimens under increasing axial load. Not only global, but also local response quantities are examined, which are difficult to capture in a phenomenological beam-column model. These comparisons also provide an opportunity for an independent verification of the predictive capabilities of the model, because these specimens were not part of the initial database that was used to develop it.

scholarly journals Nonlinear behaviour of reinforced concrete flat slabs after a column loss event

2018 ◽  
Vol 21 (14) ◽  
pp. 2169-2183 ◽  
Author(s):  
Justin M Russell ◽  
John S Owen ◽  
Iman Hajirasouliha
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Progressive Collapse ◽  
Nonlinear Behaviour ◽  
Dynamic Amplification Factor ◽  
Element Analysis ◽  
Flat Slab ◽  
Standard Design ◽  
Loss Event ◽  
Dynamic Amplification

Previous studies have demonstrated that reinforced concrete flat slab structures could be vulnerable to progressive collapse. Although such events are dynamic, simplified static analyses using the sudden column loss scenario are often used to gain an indication into the robustness of the structure. In this study, finite element analysis is used to replicate column loss scenarios on a range of reinforced concrete flat slab floor models. The model was validated against the results of scaled-slab experiments and then used to investigate the influence of different geometric and material variables, within standard design ranges, on the response of the structure. The results demonstrate that slab elements are able to effectively redistribute loading after a column loss event and therefore prevent a progressive collapse. However, the shear forces to the remaining columns were 159% of their fully supported condition and increased to 300% when a dynamic amplification factor of 2.0 was applied. It is shown that this can potentially lead to a punching shear failure in some of the slab elements.

Numerical Analysis of Punching Shear Failure of Self-Compacting Fiber Reinforced Concrete (SCFRC) Ribbed Slabs

2019 ◽  
Vol 972 ◽  
pp. 93-98
Author(s):  
Nurulain Hanida Mohamad Fodzi ◽  
M.H. Mohd Hisbany
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Nonlinear Finite Element ◽  
Fiber Reinforced Concrete ◽  
Punching Shear ◽  
Nonlinear Finite Element Method ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
Abaqus Software

This paper deals with behavior and capacity of punching shear resistance for ribbed slabs produce from self-compacting fiber reinforced concrete (SCFRC) by application of nonlinear finite element method. The analysis will be achieved by using ABAQUS software. The nonlinear finite element analysis by ABAQUS will be compare with the experimental results. Results and conclusions may be useful for establishing recommendation and need to be acknowledged.

scholarly journals Punching Shear Strength Characteristics of Flat Plate Panels Reinforced with Shearhead Collars: Experimental Investigation

2019 ◽  
Vol 5 (3) ◽  
pp. 528 ◽  
Author(s):  
Maroua Mohammed Majeed ◽  
Aamer Najim Abbas
Keyword(s):  
Experimental Investigation ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Flat Plate ◽  
Energy Absorption ◽  
Concrete Slab ◽  
Shear Capacity ◽  
Load Test ◽  
Punching Shear ◽  
Reference Specimen

This paper presents an experimental investigation on the punching shear strength of reinforced concrete flat plate slabs with shearhead collars. Eight reinforced concrete slab specimens were casted and tested under static load test, the load was applied at the center of slab by 100x100 mm steel column. The effect of the shapes, diameter and number of stiffeners has been discovered for shearheads through studying its effect on the load-deflection behavior, ultimate capacity, cracking load, failure mode, stiffness, ductility and energy absorption of tested specimens. The experimental results indicates that using square shearhead had achieved a slight increase in punching shear strength about 3% over that circular shearhead using the same surface area. Also, utilize 550 mm shearhead diameter will contribute to increase the punching shear strength about 14.5%. The increase in the number of stiffeners in specimen (CS4) had reduced the ultimate punching shear capacity by 20.3% over reference specimen. The first crack was decreased from 12.5kN to 7.5kN, when increases the number of stiffeners from one to two. The cracking load was increased with the increase of the diameter of circular shearhead from 10kN to 15Kn in specimens of 336mm and 550mm respectively. The specimen with 336mm diameter and 30mm height circular shearhead achieved 427 kN.m energy absorption, it is higher than the energy absorption of reference specimen by 2.6%. Also, using two stiffeners improved the energy absorption by 110.2% higher than the specimen with one stiffener.

scholarly journals New Methods to Resisting Punching Shear Stress in Reinforced Concrete Flat Slabs

2018 ◽  
Vol 8 (02) ◽  
Author(s):  
Fatma M. Eid ◽  
Tayel Magdy ◽  
Ebada Ahmed
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Shear Capacity ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Reinforcement System ◽  
Strength Concrete ◽  
Flat Slabs ◽  
The Difference ◽  
Compact Strength

Punching shear failure is a major problem encountered in the design of reinforced concrete flat slabs. The utilization of shear reinforcement via shear studs or other means has become a choice for improving the punching shear capacity. In this study, a new alternative of reinforcement modalities were tested and demonstrated the effect of self-compact concrete on the punching shear capacity, beside that compared between the difference codes to identify the suitable one for determining the position of critical section of punching shear. Nevertheless, in this investigation, the proposed reinforcement system is examined for interior columns only. An experimental work consisting of six specimens: five of them were cast with normal reinforced concrete and one was cast with self-compact strength concrete. The obtained results indicate that the proposed shear reinforcement system has a positive effect in the enhancement of the punching shear capacity of interior slab–column connection of self-compact strength concrete.

Sign in / Sign up

Export Citation Format

Share Document