Generation of pressure–impulse diagrams for failure modes of RC columns subjected to blast loads

2019 ◽  
Vol 100 ◽  
pp. 520-535 ◽  
Author(s):  
Runqing Yu ◽  
Li Chen ◽  
Qin Fang ◽  
Haichun Yan ◽  
Guoliang Chen
Keyword(s):  
Failure Modes ◽  
Blast Loads ◽  
Rc Columns ◽  
Pressure Impulse

Empirical Formulae To Predict Pressure And Impulsive Asymptotes For P–I Diagrams Of RC Columns Strengthened With FRP

2011 ◽  
Author(s):  
A. A. Mutalib ◽  
Norhisham Bakhary
Keyword(s):  
Concrete Strength ◽  
Numerical Results ◽  
Fiber Reinforced Polymer ◽  
Blast Loads ◽  
Fiber Reinforced ◽  
Rc Columns ◽  
Pressure Impulse ◽  
Reinforced Polymer ◽  
Blast Response ◽  
Parametric Studies

Kajian terhadap keupayaan struktur dalam menahan beban letupan menggunakan Fiber Reinforced Polymer (FRP) adalah sangat terhad. Dalam kajian ini, satu analisis terhadap keupayaan FRP bagi menahan beban letupan dilakukan. Tujuan analisis ini adalah untuk memperolehi hubungan antara kekuatan FRP, bilangan lapisan ketebalan FRP dan susunatur FRP bagi menahan kekuatan sesuatu beban letupan. Kajian ini dilakukan mengunakan model tiang diperkukuh dengan FRP yang dibina menggunakan perisian LS–DYNA. Ia melibatkan beberapa siri simulasi untuk meramalkan tindakbalas letupan dan kerosakkan pada tiang sekiranya sesuatu beban letupan dikenakan. Melalui simulasi ini, kekuatan FRP, bilangan lapisan ketebalan FRP dan susunatur FRP dapat ditentukan. melalui keputusan–keputusan yang diperolehi, pressure–impulse diagram (P–I) bagi tiang yang diperkukuhkan dengan FRP dapat dibentuk. Kata kunci: Pengukuhan; beban letupan; FRP; P–I diagrams There are only limited studies that directly correlate the increase in structural capacities in resisting the blast loads with the fiber reinforced polymer (FRP) strengthenin. In this paper, numerical analyses of dynamic response and damage of reinforced concrete (RC) columns strengthened with FRP to blast loads are carried out using the commercial software LS–DYNA. A series of simulations are performed to predict the blast response and damage of columns with different FRP type. The simulations also involved parametric studies by varying the FRP thickness, configuration, different column dimension, concrete strength, and longitudinal and transverse reinforcement ratio. The numerical results are used to develop pressure–impulse (P–I) diagrams of FRP strengthened RC columns. Based on the numerical results, the empirical formulae are derived to calculate the pressure and impulse asymptotes of the P–I diagrams of RC columns strengthened with FRP. Key words: Strengthening; blast loads; FRP; P–I diagrams

scholarly journals Experimental Research on Reinforced Concrete Columns Strengthened with Steel Jacket and Concrete Infill

2021 ◽  
Vol 11 (9) ◽  
pp. 4043
Author(s):  
Aleksandar Landović ◽  
Miroslav Bešević
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Experimental Research ◽  
Failure Modes ◽  
Steel Tube ◽  
Rc Columns ◽  
Rc Column ◽  
Steel Jacket ◽  
Ductile Behavior

Experimental research on axially compressed columns made from reinforced concrete (RC) and RC columns strengthened with a steel jacket and additional fill concrete is presented in this paper. A premade squared cross-section RC column was placed inside a steel tube, and then the space between the column and the tube was filled with additional concrete. A total of fourteen stub axially compressed columns, including nine strengthened specimens and five plain reinforced concrete specimens, were experimentally tested. The main parameter that was varied in the experiment was the compressive strength of the filler concrete. Three different concrete compression strength classes were used. Test results showed that all three cross-section parts (the core column, the fill, and the steel jacket) worked together in the force-carrying process through all load levels, even if only the basic RC column was loaded. The strengthened columns exhibited pronounced ductile behavior compared to the plain RC columns. The influence of the test parameters on the axial compressive strength was investigated. In addition, the specimen failure modes, strain development, and load vs. deformation relations were registered. The applicability of three different design codes to predict the axial bearing capacity of the strengthened columns was also investigated.

Seismic assessment of reinforced concrete columns with short lap splices

2021 ◽  
pp. 875529302199483
Author(s):  
Eyitayo A Opabola ◽  
Kenneth J Elwood
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Failure Modes ◽  
Concrete Columns ◽  
Seismic Assessment ◽  
Rc Columns ◽  
Lap Splices ◽  
Displacement Response ◽  
Force Displacement ◽  
Probable Failure

Existing reinforced concrete (RC) columns with short splices in older-type frame structures are prone to either a shear or bond mechanism. Experimental results have shown that the force–displacement response of columns exhibiting these failure modes are different from flexure-critical columns and typically have lower deformation capacity. This article presents a failure mode-based approach for seismic assessment of RC columns with short splices. In this approach, first, the probable failure mode of the component is evaluated. Subsequently, based on the failure mode, the force–displacement response of the component can be predicted. In this article, recommendations are proposed for evaluating the probable failure mode, elastic rotation, drift at lateral failure, and drift at axial failure for columns with short splices experiencing shear, flexure, or bond failures.

Rehabilitation of Corrosion-Damaged Substandard RC Columns Using FRP Sheets

2013 ◽  
Vol 639-640 ◽  
pp. 1096-1103 ◽  
Author(s):  
Aras Kalyoncuoglu ◽  
Pooya Ghaffari ◽  
Caglar Goksu ◽  
Alper Ilki
Keyword(s):  
Failure Modes ◽  
Effective Cross Section ◽  
Lateral Loads ◽  
Reinforcing Bars ◽  
Rc Columns ◽  
Accelerated Corrosion ◽  
Drift Capacity ◽  
Existing Structures ◽  
Cover Cracking ◽  
Experimental Findings

Corrosion is one of the major problems for the existing structures and may cause significant decrease in drift capacity and strength of RC (reinforced concrete) columns due to reduction of effective cross-section of reinforcing bars, alteration of bond characteristics between reinforcing bars and concrete, and cover cracking along the reinforcing bars. Therefore, rehabilitation of corrosion-damaged columns is extremely important, particularly in seismic regions and if a substandard construction methodology is used. In this paper, an experimental work is presented on the seismic performance of rehabilitated/retrofitted substandard RC columns, which were damaged due to corrosion of reinforcing bars. For this purpose, four substandard columns were tested under high axial load and reversed cyclic lateral loads. The columns were constructed with extremely low quality concrete and plain round bars. The spacing and details of transverse reinforcing bars did not comply with the code regulations as well. Then, the specimens, except the reference one, were subjected to accelerated corrosion process. One of the corrosion-damaged specimens was tested before rehabilitation/retrofitting procedure, while the other two specimens were tested after rehabilitation/retrofitting procedure. The test results clearly demonstrated the efficiency of the applied rehabilitation/retrofitting procedure, both in terms of strength and ductility. Furthermore, analytical predictions about strength and failure modes of the specimens are compared with experimental findings.

Numerical analysis of axially loaded RC columns subjected to the combination of impact and blast loads

2020 ◽  
Vol 219 ◽  
pp. 110924 ◽  
Author(s):  
Gholamreza Gholipour ◽  
Chunwei Zhang ◽  
Asma Alsadat Mousavi
Keyword(s):  
Numerical Analysis ◽  
Blast Loads ◽  
Rc Columns ◽  
Axially Loaded

Dynamic Response and Failure Mode Analysis on Light-Weight Steel Columns under Blast Loads

2012 ◽  
Vol 166-169 ◽  
pp. 1489-1497 ◽  
Author(s):  
Shi Yan ◽  
Lei Liu ◽  
Peng Li ◽  
Zhi Qiang Xin ◽  
Bao Xin Qi
Keyword(s):  
Dynamic Response ◽  
Failure Mode ◽  
Failure Modes ◽  
Shear Failure ◽  
Mode Analysis ◽  
Material Strength ◽  
Light Weight ◽  
Blast Loads ◽  
Element Analysis ◽  
Steel Columns

The dynamic response and failure mode of light-weight steel columns under blast loads were studied in this paper by using nonlinear finite element analysis (FEA) software ANSYS/ LS-DYNA, aiming to develop the degree and modes of the excessive plastic deformation during failures of the columns under diverse parameters. The damaged columns with initial blast-induced deformation may evidently influence vertical stability of light-weight steel frame structures. During the numerical simulation, the element of three dimensional solid SOLID164 was used, and the strain rate effect on material strength was included in the material model with Plastic-Kinematic (MAT-03). The main parameters included in the analysis were boundary conditions, scaled distances of explosions, and the vertical compressive load ratios applied on tops of the columns. The results showed that the column with both two fixed ends was the most beneficial to resist blast shock wave, the horizontal displacement at the middle span of the columns were obviously decreasing as increasing of the scaled distances of the explosion, and the axial compression ratio only significantly influenced the column with a sliding end. The failure modes of the developed columns may be summarized as bending failure, direct shear failure, and bending shear combination failure.

The Simulation Study on Degree of Protection/Damage under Blast Loads

2012 ◽  
Vol 271-272 ◽  
pp. 1229-1233
Author(s):  
Yun Chen ◽  
Hua Wang ◽  
Shun Shan Feng
Keyword(s):  
Metal Plate ◽  
Structure Design ◽  
Blast Loads ◽  
Target Plate ◽  
Pressure Impulse ◽  
Degree Of Protection ◽  
The Military ◽  
Target Metal ◽  
Important Basis ◽  
Good Agreement

The degree of protection/damage of the target is an important basis for the target structure design. In the military field, the target can be equivalent to a target metal plate with the certain thickness. The degree of protection can be divided through the effect of target plate under blast loads. Considering the reflected parameters, the reflected pressure-impulse criterion can be used to assess the damage caused by the blast. Through the combination of theoretical analysis and numerical simulation, the target plate’s pressure-impulse diagrams of different degrees are obtained. The results of the experiments and simulations are found in good agreement, which validates the numerical model.

scholarly journals Damage evaluation of ultra-high performance concrete columns after blast loads

2018 ◽  
Vol 9 (1) ◽  
pp. 44-64 ◽  
Author(s):  
Jun Li ◽  
Chengqing Wu
Keyword(s):  
High Performance ◽  
Dynamic Behaviour ◽  
High Performance Concrete ◽  
Concrete Columns ◽  
Constitutive Law ◽  
Column Height ◽  
Uniaxial Tensile ◽  
Blast Loads ◽  
Ultra High Performance Concrete ◽  
Pressure Impulse

As emerging advanced construction material, ultra-high performance concretes have seen increasing field applications over the past two decades to take advantages of their ultra-high mechanical strength and durability; yet the systematic study on its dynamic behaviour under impact and blast loads is not commonly seen. This article presents an experimental and numerical study on the static and dynamic behaviour of an existing ultra-high performance concrete material. Experimental study on its flexural behaviour under static loads is conducted and an inverse study is carried out to derive its uniaxial tensile constitutive law. The derived relationship is used in the material model in hydro-code LS-DYNA together with dynamic material properties to study ultra-high performance concrete columns under blast loads. The residual loading capacity of the column is studied and pressure–impulse diagrams for assessing the ultra-high performance concrete column damage under blast loads are proposed. Parametric study on effects of ultra-high performance concrete strength, column height, cross-section size and reinforcement ratio is performed and analytical equations are proposed for generating pressure–impulse diagrams for generic ultra-high performance concrete columns.

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