scholarly journals Predicting shear failure in reinforced concrete members using a three-dimensional peridynamic framework

2021 ◽  
Author(s):  
Mark Hobbs ◽  
Gabriel Hattorri ◽  
John Orr
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Shear Failure ◽  
Load Transfer ◽  
Three Dimensional ◽  
Constitutive Law ◽  
Concrete Members ◽  
Predictive Error ◽  
Wide Range ◽  
Transfer Mechanisms

The assumptions made in design codes can result in unconservative predictions of shear strength for reinforced concrete members. The limitations of empirical methods have prompted the development and use of numerical techniques. A three-dimensional bond-based peridynamic framework is developed for predicting shear failure in reinforced concrete members. The predictive accuracy and generality of the framework is assessed against existing experimental results. Nine reinforced concrete beams that exhibit a wide range of failure modes are modelled. The shear-span-to-depth ratio is systematically varied from 1 to 8 to facilitate a study of different load-transfer mechanisms and failure modes. A comprehensive validation study such as this has until now been missing in the peridynamic literature. A bilinear constitutive law is employed, and the sensitivity of the model is tested using two levels of mesh refinement. The predictive error between the experimental and numerical failure loads ranges from +3% to -57%, highlighting the importance of validation against a series of problems. The results demonstrate that the model captures many of the factors that contribute to shear and bending resistance. New insights into the capabilities and deficiencies of the peridynamic model are gained by comparing the expected load-transfer mechanisms with the predictive error.

Machine learning-based failure mode identification of RCSPSW

2021 ◽  
Author(s):  
Dongqi Jiang ◽  
Shanquan Liu ◽  
Tao Chen ◽  
Gang Bi
Keyword(s):  
Machine Learning ◽  
Failure Mode ◽  
Failure Modes ◽  
Shear Failure ◽  
Tall Buildings ◽  
Shear Walls ◽  
Superior Performance ◽  
Ann Model ◽  
Mode Recognition ◽  
Wide Range

<p>Reinforced concrete – steel plate composite shear walls (RCSPSW) have attracted great interests in the construction of tall buildings. From the perspective of life-cycle maintenance, the failure mode recognition is critical in determining the post-earthquake recovery strategies. This paper presents a comprehensive study on a wide range of existing experimental tests and develops a unique library of 17 parameters that affects RCSPSW’s failure modes. A total of 127 specimens are compiled and three types of failure modes are considered: flexure, shear and flexure-shear failure modes. Various machine learning (ML) techniques such as decision trees, random forests (RF), <i>K</i>-nearest neighbours and artificial neural network (ANN) are adopted to identify the failure mode of RCSPSW. RF and ANN algorithm show superior performance as compared to other ML approaches. In Particular, ANN model with one hidden layer and 10 neurons is sufficient for failure mode recognition of RCSPSW.</p>

Failure analysis of three-dimensional braided composite tubes under torsional load: Experimental study

2017 ◽  
Vol 36 (12) ◽  
pp. 878-888 ◽  
Author(s):  
Xiaopei Wang ◽  
Deng’an Cai ◽  
Chao Li ◽  
Fangzhou Lu ◽  
Yu Wang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Failure Modes ◽  
Shear Failure ◽  
Three Dimensional ◽  
Damage Mechanism ◽  
Test Device ◽  
Composite Tubes ◽  
Torsional Strength ◽  
Braided Composite ◽  
Torsional Load

An experimental study on the effects of braided processes on the torsional strength, torsional modulus and failure modes of the three-dimensional braided composite tubes are presented. Based on the movement of carries, the yarn traces of three-dimensional braided composite tubes are analyzed systematically. Four different three-dimensional braided composite tubes are formed by resin transfer molding, and a number of torsional tests are performed respectively using a special test device. It is found that the torsional strength of three-dimensional five-directional braided composite tubes is higher than others, while the torsional modulus of three-dimensional multi-layer wrapping braided composite tubes is the highest. Furthermore, the damage behaviors of 3D braided composite tubes are significantly influenced by braiding process. One focus is to evaluate the damage mechanism of three-dimensional braided composite tubes by cutting the specimens and using scanning electron microscopy. Under torsional load, three-dimensional five-directional braided composite tubes and three-dimensional surface-core five-directional braided composite tubes are fractured in compression and shear failure, while three-dimensional multi-layer wrapping braided composite tubes and three-dimensional seven-directional braided composite tubes are split open in tensile and shear failure.

Analysis on Flexural Capacity of FRP Reinforced Concrete Members

2012 ◽  
Vol 446-449 ◽  
pp. 98-101
Author(s):  
Chun Xia Li ◽  
Zhi Sheng Ding ◽  
Shi Lin Yan
Keyword(s):  
Reinforced Concrete ◽  
Material Properties ◽  
Failure Modes ◽  
Reinforcement Ratio ◽  
Flexural Capacity ◽  
Steel Reinforced Concrete ◽  
Concrete Members

The balanced reinforcement ratio of FRP-reinforced concrete members and the flexural capacity under two different failure modes (concrete crushing and FRP rupture) are established, based on the analysis on flexural capacity of steel-reinforced concrete members in current concrete code. The effect of material properties on the balanced ratio, the variation of flexural capacity with different reinforcement ratio and a simplified nominal flexural capacity under FRP-rupture failure are derived.

Experimental investigation and modeling of dynamic thermomechanical behavior of 4-harness satin weave carbon/epoxy composites

2017 ◽  
Vol 31 (9) ◽  
pp. 1181-1203 ◽  
Author(s):  
Xueyao Hu ◽  
Hui Guo ◽  
Weiguo Guo ◽  
Feng Xu ◽  
Longyang Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Composite Laminates ◽  
Failure Modes ◽  
Shear Failure ◽  
Experimental Studies ◽  
Temperature Shift ◽  
Thermomechanical Coupling ◽  
Longitudinal Splitting ◽  
Wide Range

Theoretical and experimental studies on the compressive mechanical behavior of 4-harness satin weave carbon/epoxy composite laminates under in-plane loading are conducted over the temperature range of 298–473 K and the strain rate range of 0.001–1700/s in this article. The stress–strain curves of 4-harness satin weave composites are obtained at different strain rates and temperatures, and key mechanical properties of the material are determined. The deformation mechanism and failure morphology of the samples are observed and analyzed by scanning electron microscope (SEM) micrographs. The results show that the uniaxial compressive mechanical properties of 4-harness satin weave composites are strongly dependent on the temperature but are weakly sensitive to strain rate. The peak stress and elastic modulus of the material have the trend of decrease with the increasing of temperature, and the decreasing trend can be expressed as the functional relationship of temperature shift factor. In addition, SEM observations show that the quasi-static failure mode of 4-harness satin weave composites is shear failure along the diagonal lines of the specimens, while the dynamic failure modes of the material are multiple delaminations and longitudinal splitting, and with the increasing of temperature, its longitudinal splitting is more serious, but the delamination is relatively reduced. A constitutive model with thermomechanical coupling effects is proposed based on the experimental results and the increment theory of elastic–plastic mechanics. The experimental verification and numerical analysis show that the model is shown to be able to predict the finite deformation behavior of 4-harness satin weave composites over a wide range of temperatures.

scholarly journals Uniaxial Cyclic Tests on Reinforced Concrete Members with Lap Splices

2019 ◽  
Vol 35 (2) ◽  
pp. 1023-1043 ◽  
Author(s):  
Danilo Tarquini ◽  
João P. Almeida ◽  
Katrin Beyer
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Local Deformation ◽  
Experimental Program ◽  
Loading History ◽  
Cyclic Tests ◽  
Continuous Reinforcement ◽  
Lap Splices ◽  
Lap Splice ◽  
Concrete Members

This data paper presents the quasi-static uniaxial cyclic tests of 24 reinforced concrete members, of which 22 feature lap splices and 2 are reference units with continuous reinforcement. The objective of the experimental program is to investigate the influence of lap splice length ( ls), confining reinforcement, and loading history on the behavior of lap splices. Particular attention is placed on the measurement of local deformation quantities, such as lap splice strains and rebar-concrete slip. Details of the geometry and reinforcement layout of the specimens as well as the employed test setup, instrumentation, and loading protocols are provided. The global behavior of the test units, including the observed crack pattern and failure modes, are discussed. The organization of the experimental data, which are made available for public use under DOI: 10.5281/zenodo.1205887, is outlined in detail.

A Study on the Safety Assessment of Car-Body Structure for Urban EMU

2007 ◽  
Vol 345-346 ◽  
pp. 673-676
Author(s):  
Jong Duk Chung ◽  
Jang Sik Pyun
Keyword(s):  
Safety Assessment ◽  
Load Transfer ◽  
Permanent Deformation ◽  
Three Dimensional ◽  
Engineering Analysis ◽  
Analysis Techniques ◽  
Crashworthiness Analysis ◽  
Safety Diagnosis ◽  
Transfer Mechanisms ◽  
Good Agreement

Engineering safety diagnosis of crashed subway electric multiple units (EMUs) was conducted for safety assessment. Several advanced engineering analysis techniques including nondestructive evaluation (NDE) techniques and stress and structural analyses programs, were performed for better understandings and exploration of failure analysis and safety concerns. Moreover, stress and structural analyses using commercial I-DEAS software provided important information on stress distribution and load transfer mechanisms as well as the amount of damages during the crash. One-dimensional crashworthiness was conducted to estimate the speed at the time of the accident by investigating the permanent deformation of the train. The estimated speed was used as the input value of a three-dimensional crashworthiness analysis. A good agreement has been found between structural analysis results and the results of actual damages in EMUs during crash. In this investigation, various advanced engineering analysis techniques for the safety analysis of subway EMUs have been introduced and the analysis results have been used to provide the critical information for the safety assessment of crashed EMUs.

Experimental Study on Strength and Failure Characteristics of Reinforced Concrete Plate under Complex Stresses Conditions

2013 ◽  
Vol 357-360 ◽  
pp. 699-704 ◽  
Author(s):  
Guang Yang ◽  
Zuo Zhou Zhao ◽  
Xiao Gang He
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Shear Failure ◽  
Biaxial Tension ◽  
Reduction Factor ◽  
Failure Characteristics ◽  
Concrete Plate ◽  
Principal Tensile Stress ◽  
Force Ratio ◽  
Practical Engineering

To study the biaxial strength and failure characteristics of reinforced concrete in the state of biaxial tension-compression stresses and provide some suggestions for the practical engineering design, 3 one-third scale reinforced concrete (RC) plate specimens are tested. The results indicate that, in biaxial tension-compression stresses, reinforced concrete cracks in the direction normal to the principal tensile stress direction and presents the characteristics of shear failure modes. The test device could simulate the required stress condition. The compression strength of reinforced concrete is obviously lower than the uniaxial strength fc. The reduction factor k is about 0.55~0.75 which varies with different tension-compression force ratio. Concrete material takes part in the tension process of reinforced concrete and shares part of the tension, while the share ratio decreases as concrete cracks gradually.

scholarly journals Soft Missile Impact on Shear Reinforced Concrete Wall

2010 ◽  
Vol 5 (4) ◽  
pp. 426-436 ◽  
Author(s):  
Arja Saarenheimo ◽  
◽  
Kim Calonius ◽  
Markku Tuomala ◽  
Ilkka Hakola ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Transverse Shear ◽  
Shear Failure ◽  
Three Dimensional ◽  
Concrete Wall ◽  
Concrete Walls ◽  
Shell Elements ◽  
Bending Mode ◽  
Reinforced Concrete Wall ◽  
Wall Deformation

In developing numerical approaches for predicting the response of reinforced concrete structures impacted on by deformable projectiles, we predict structural behavior collapse and damage using simple analysis and extensive nonlinear finite element (FE)models. To verify their accuracy, we compared numerical results to experimental data and observations on impact-loaded concrete walls with bending and transverse shear reinforcement. Different models prove adequate for different cases and are sensitive to different variables, making it important to rely on more than a single model alone. For wall deformation in bending mode, deflection is predicted reasonably well by simple four-node shell elements. Where punching dominates, transverse shear behavior must be considered. Formation of a shear failure cone is modeled using three-dimensional solid elements.

scholarly journals A Design Method to Induce Ductile Failure of Flexural Strengthened One-Way Reinforced Concrete Slabs

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7647
Author(s):  
Huy Q. Nguyen ◽  
Tri N. M. Nguyen ◽  
Do Hyung Lee ◽  
Jung J. Kim
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Shear Failure ◽  
Design Method ◽  
Concrete Slab ◽  
Ductile Failure ◽  
Reinforced Concrete Slabs ◽  
Failure Loads ◽  
Ultimate Failure ◽  
Rc Slabs

Strengthening existing reinforced concrete (RC) slabs using externally bonded materials is increasingly popular due to its adaptability and versatility. Nevertheless, ductility reduction of the rehabilitated flexural members with these materials can lead to brittle shear failure. Therefore, a new approach for strengthening is necessary. This paper presents a methodology to induce ductile failure of flexural strengthened one-way RC slabs. Ultimate failure loads can be considered to develop the proposed design methodology. Different failure modes corresponding to ultimate failure loads for RC slabs are addressed. Flexural and shear failure regions of RC slabs can be established by considering the failure modes. The end span of the concrete slab is shown for a case study, and numerical examples are solved to prove the essentiality of this methodology.

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