A spherical smart aggregate sensor based electro-mechanical impedance method for quantitative damage evaluation of concrete

2019 ◽  
Vol 19 (5) ◽  
pp. 1560-1576 ◽  
Author(s):  
Shaoyu Zhao ◽  
Shuli Fan ◽  
Jie Yang ◽  
Sritawat Kitipornchai
Keyword(s):  
Numerical Model ◽  
Three Dimensional ◽  
Volume Ratio ◽  
Mechanical Impedance ◽  
Element Model ◽  
Impedance Method ◽  
Damage Level ◽  
Smart Aggregate ◽  
Concrete Damage ◽  
Damage Process

In this study, the concrete damage induced by compression is evaluated quantitatively using spherical smart aggregate sensor based on electro-mechanical impedance method. The sensitivity of the spherical smart aggregate sensor embedded in concrete cubes is investigated by comparing the electrical signals recorded during the compressive process with those of the smart aggregate sensor embedded in concrete cubes. Furthermore, the finite element model of concrete cube with an embedded spherical smart aggregate sensor is developed to simulate the concrete compressive tests. The concrete damaged plasticity constitutive model is utilized to simulate the concrete damage process. The numerical model is verified with the experimentally measured compressive test results. Finally, the damage volume ratio is presented to quantify the damage level of concrete based on the numerical model. The relationship between the root mean square deviation index of the conductance signatures obtained from experiments and the damage volume ratio computed by numerical simulation is established to quantify the concrete damage level. The results show that the spherical smart aggregate sensor is more sensitive than the smart aggregate sensor in monitoring the three-dimensional concrete structures. The proposed empirical fitting curve can effectively evaluate the concrete damage level quantitatively.

scholarly journals Mechanical Response of Typical Cement Concrete Pavements under Impact Loading

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Ding Fei ◽  
Yin Yan ◽  
Cai Liangcai ◽  
Tang Yaohong ◽  
Wang Xuancang
Keyword(s):  
Finite Element ◽  
Impact Loading ◽  
Mechanical Response ◽  
Impact Load ◽  
Damage Model ◽  
Three Dimensional ◽  
Element Model ◽  
Concrete Pavements ◽  
Cement Concrete ◽  
Concrete Damage

In order to study the mechanical response of cement concrete pavements under impact loading, four types of typical cement concrete pavement structures are investigated experimentally and numerically under an impact load. Full-scale three-dimensional pavement slots are tested under an impact load and are monitored for the mechanical characteristics including the deflection of the pavement surface layer, the strain distribution at the bottom of the slab, and the plastic damage and cracking under the dynamic impact load. Numerical analysis is performed by developing a three-dimensional finite element model and by utilizing a cement concrete damage model. The results show that the calculation results based on the cement concrete damage model are in reasonable agreement with the experimental results based on the three-dimensional test slot experiment. The peak values of stress and strain as monitored by the sensors are analyzed and compared with the numerical results, indicating that the errors of numerical results from the proposed model are mostly within 10%. The rationality of the finite element model is verified, and the model is expected to be a suitable reference for the analysis and design of cement concrete pavements.

The Effect of the Reeling Laying Method on the Collapse Pressure of Steel Pipes for Deepwater

2004 ◽  
Author(s):  
Ilson P. Pasqualino ◽  
Silvia L. Silva ◽  
Segen F. Estefen
Keyword(s):  
Numerical Model ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Element Model ◽  
External Pressure ◽  
Test Facility ◽  
Collapse Pressure ◽  
Steel Pipes ◽  
Custom Made ◽  
Nonlinear Finite Element Model

This work deals with a numerical and experimental investigation on the effect of the reeling installation process on the collapse pressure of API X steel pipes. A three-dimensional nonlinear finite element model was first developed to simulate the bending and straightening process as it occurs during installation. The model is then used to determine the collapse pressures of both intact and plastically strained pipes. In addition, experimental tests on full-scale models were carried out in order to calibrate the numerical model. Pipe specimens are bent on a rigid circular die and then straightened with the aid of a custom-made test facility. Subsequently, the specimens are tested quasi-statically under external pressure until collapse in a pressure vessel. Unreeled specimens were also tested to complete the database for calibrating the numerical model. The numerical model is finally used to generate collapse envelopes of reeled and unreeled pipes with different geometry and material.

Progressive Damage Analysis of Full-Wrapped Composite Gas Cylinder Under Overload Condition and Prediction of Its Bursting Pressure

2015 ◽  
Author(s):  
Zewu Wang ◽  
Guojing Zhang ◽  
Peiqi Liu ◽  
Liangzhi Xia
Keyword(s):  
Numerical Model ◽  
Failure Process ◽  
Damage Model ◽  
Three Dimensional ◽  
High Strength ◽  
Reduction Factor ◽  
Bursting Pressure ◽  
Progressive Damage ◽  
Gas Cylinder ◽  
Damage Process

Fiber is widely used as a reinforcing material on the gas cylinder owing to good stiffness-to-weight and designability as well as high strength. However, it is difficult to analyze the failure process of a full-wrapped composite gas cylinder because of the anisotropy of composite material and complexity of a full-wrapped geometric structure. In this study, the three dimensional (3D) numerical model of a full-wrapped gas cylinder was first developed and used for calculating its stress distribution. And then the Hashin failure mode and reduction factor of elastic modulus were integrated into the numerical model by using a user subroutine. Lastly, the progressive damage process of the gas cylinder was analyzed in detail under overload conditions. The results indicated that the proposed progressive damage model could not only reproduce the damage process of the full-wrapped gas cylinder, but also predict the critical bursting pressure. This work will in the future help to guide the calculation of load-carrying capacity and failure analysis of the composite gas cylinder.

Experimental and numerical study of process-induced total spring-in of corner-shaped composite parts

2016 ◽  
Vol 51 (16) ◽  
pp. 2347-2361 ◽  
Author(s):  
K Furkan Çiçek ◽  
Merve Erdal ◽  
Altan Kayran
Keyword(s):  
Numerical Model ◽  
Numerical Study ◽  
Three Dimensional ◽  
Interaction Mechanism ◽  
Element Model ◽  
Shape Design ◽  
Optical Scanning ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Good Agreement

Process-induced total spring-in of corner-shaped composite parts manufactured via autoclave-forming technique using unidirectional prepreg is studied both numerically and experimentally. In the numerical study, a three-dimensional finite element model which takes into account the cure shrinkage of the resin, anisotropic material properties of the composite part and the tool-part interaction is developed. The outcome of the numerical model is verified experimentally. For this purpose, U-shaped composite parts are manufactured via autoclave-forming technique. Process-induced total spring-in, due to the combined effect of material anisotropy and tool-part interaction, at different sections of the U-shaped parts are measured with use of the combination of the three-dimensional optical scanning technique and the generative shape design. Total spring-in determined by the numerical model is found to be in good agreement with the average total spring-in measured experimentally. The effect of tool-part interaction mechanism on the total spring-in is studied separately to ascertain its effect on the total spring-in behavior clearly. It is shown that with the proper modeling of the tool-part interaction, numerically determined total spring-in approaches the experimentally determined total spring-in.

Finite Element Model for Damage Detection in Three-Dimensional Cube Structures

2012 ◽  
Vol 430-432 ◽  
pp. 1468-1471
Author(s):  
Wei Yan ◽  
Wan Chun Li ◽  
Wei Wang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Mechanical Impedance ◽  
Element Model ◽  
Structural System ◽  
Damage Propagation ◽  
Bond Layer ◽  
Dimensional Finite Element ◽  
Dimensional Cube ◽  
Three Dimensional Finite Element

Based on three-dimensional finite element method (FEM), an accurate electro-mechanical impedance (EMI) model for a damaged cube structure is established in the paper. The damages are simulated by the reduction in Young’s modulus in the certain area of the cube structure. A coupled structural system consisting of PZT patch, bond layer and host structure is taken into account. Both the effects of the damage severity and damage propagation on EMI signatures are then investigated. The numerical computation indicates that the present EMI model can be employed to detect the damages in the structures.

Three-Dimensional Damage Analysis of Concrete Surrounding the Spiral Case in the Nuozhadu Hydropower Station

2011 ◽  
Vol 393-395 ◽  
pp. 1048-1053
Author(s):  
Ze Li ◽  
Li Xiang Zhang
Keyword(s):  
Three Dimensional ◽  
Element Model ◽  
Water Hammer ◽  
Damage Effect ◽  
Hydropower Station ◽  
Dimensional Finite Element ◽  
Spiral Case ◽  
Concrete Damage ◽  
Three Dimensional Finite Element ◽  
Case Structure

Studies have shown that the internal pressure of the spiral case could cause damage of the surrounding concrete, and the damage range and level are possible to grow with the repeated action of water hammer pressure. The security of spiral case structure may be adversely affected by damage of the surrounding concrete. In this paper, the case study of a spiral case which located in Nuozhadu hydropower station in Yunnan Province is presented. In order to analyze the damage effect of surrounding concrete under the repeated maximal water hammer pressure, a three-dimensional finite element model is established by ABAQUS software. In calculation, the contact elements are used to simulate the feature of frictional contact between steel liner and surrounding concrete, and the concrete damage plasticity constitutive model is adopted to describe the tensile characteristic of concrete. At last, according to the results of simulation, the damage range and level are investigated.

scholarly journals Seismic Response of Nonseismically Designed Reinforced Concrete Low Rise Buildings

2018 ◽  
Vol 24 (4) ◽  
pp. 112
Author(s):  
Thamir K. Mahmoud ◽  
Hayder A. Al-Baghdadi
Keyword(s):  
Reinforced Concrete ◽  
Numerical Model ◽  
Three Dimensional ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Inelastic Behavior ◽  
Base Shear ◽  
Earthquake Excitation ◽  
Inelastic Responses ◽  
Concrete Damage

In this paper, the time-history responses of a square plan two-story reinforced concrete prototype building, considering the elastic and inelastic behavior of the materials, were studied numerically. ABAQUS software was used in three-dimensional (3D) nonlinear dynamic analysis to predict the inelastic response of the buildings. Concrete Damage Plasticity Model (CDPM) has been used to model the inelastic behavior of the reinforced concrete building under seismic excitation. The input data included geometric information, material properties, and the ground motion. The building structure was designed only for gravity load according to ACI 318 with non-seismically detailing requirements. The prototype building was subjected to El Centro 1940 NS earthquake at different amplitudes (PGA=0.05g, PGA=0.15g, and PGA=0.32g). The elastic and inelastic responses of the 3D numerical model of the same building were evaluated. The differences between the elastic and inelastic displacements and base shear forces were analyzed. It was found from the results that base shear responses are significantly more sensitive to the numerical model of analysis than displacement responses. The evaluation showed that the base shear force and displacement responses of a two-story R.C. building subjected to severe earthquake excitation are very sensitive to the numerical model used whether it is elastic or inelastic.  

scholarly journals Strut and Tie Modelling of Reinforced Concrete Deep Beams Under Static and Fixed Pulsating Loading

2020 ◽  
Vol 23 (3) ◽  
pp. 306-312
Author(s):  
Ajibola Ibrahim Quadri
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Three Dimensional ◽  
Element Model ◽  
Strength Properties ◽  
Material Strength ◽  
Deep Beam ◽  
Damage Level ◽  
Strut And Tie ◽  
Applied Loading

Numerical analysis of the performance of reinforced concrete (RC) deep beam subjected to static and fixed-point pulsating loading at the midpoint has been investigated. Three-dimensional nonlinear finite element model using the Strut and Tie approach was adopted. The damage level under the influence of the applied fixed pulsating loading is higher than the static applied loading, hence early crack was observed because of the stepwise loading in the form of vibration. Although the Strut and Tie approach gave a good estimation of the resistance capacity of the beam, the beam undergo high shear damage when subjected to these two types of loading. Material strength properties, applied loadings and cross-sections adopted are some of the factors that affect the performance of the deep beam.

A structural numerical model for the optimization of double pelvic osteotomy in the early treatment of canine hip dysplasia

2017 ◽  
Vol 30 (04) ◽  
pp. 256-264 ◽  
Author(s):  
Mara Terzini ◽  
Luca Mossa ◽  
Cristina Bignardi ◽  
Piero Costa ◽  
Alberto Audenino ◽  
...  
Keyword(s):  
Numerical Model ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Pelvic Osteotomy ◽  
Element Model ◽  
Radiographic Images ◽  
Bone Stress ◽  
Dimensional Measurements ◽  
Kinematic Analyses ◽  
Deformable Bodies

SummaryBackground: Double pelvic osteotomy (DPO) planning is usually performed by hip palpation, and on radiographic images which give a poor representation of the complex three-dimensional manoeuvre required during surgery. Furthermore, bone strains which play a crucial role cannot be foreseen.Objective: To support surgeons and designers with biomechanical guidelines through a virtual model that would provide bone stress and strain, required moments, and three-dimensional measurements.Methods: A multibody numerical model for kinematic analyses has been coupled to a finite element model for stress/strain analysis on deformable bodies. The model was parametrized by the fixation plate angle, the iliac osteotomy angle, and the plate offset in ventro-dorsal direction. Model outputs were: acetabular ventro-version (VV) and lateralization (L), Norberg (NA) and dorsal acetabular rim (DAR) angles, the percentage of acetabular coverage (PC), the peak bone stress, and moments required to deform the pelvis.Results: Over 150 combinations of cited parameters and their respective outcome were analysed. Curves reporting NA and PC versus VV were traced for the given patient. The optimal VV range in relation to NA and PC limits was established. The 25° DPO plate results were the most similar to 20° TPO. The output L grew for positive iliac osteotomy inclinations. The 15° DPO plate was critical in relation to DAR, while very large VV could lead to bone failure.Clinical significance: Structural models can be a support to the study and optimization of DPO as they allow for foreseeing geometrical and structural outcomes of surgical choices.ORCID iDALA: http://orcid.org/0000-0002-4877-3630AV: http://orcid.org/0000-0003-2837-7822CB: http://orcid.org/0000-0002-7065-2552EZ: http://orcid.org/0000-0003-4121-6126MT: http://orcid.org/0000-0002-5699-6009

Numerical Investigation of Oblique Pipeline/Soil Interaction in Sand

2010 ◽  
Author(s):  
Nasser Daiyan ◽  
Shawn Kenny ◽  
Ryan Phillips ◽  
Radu Popescu
Keyword(s):  
Numerical Model ◽  
Numerical Study ◽  
Three Dimensional ◽  
Element Model ◽  
Relative Displacement ◽  
Soil Behavior ◽  
Ground Deformations ◽  
Centrifuge Tests ◽  
Parametric Studies ◽  
Pass Through

Energy pipelines pass through various environmental and geotechnical conditions. They are usually buried and can be subjected to geohazards like landslides, fault movements or large subsidence resulting in large permanent ground deformations along part of their length. The effect of large permanent ground deformations on buried pipelines can be critical for their integrity and safety. Understanding this effect is important for pipeline designers. In the current engineering guidelines the pipeline/soil interaction has been idealized using structural modeling which evaluates the soil behavior using discrete springs with load-displacement relationships provided in three perpendicular directions (longitudinal, lateral horizontal and vertical). These springs are usually independent and during a 3D pipe/soil relative displacement they can not account for cross effects due to shear interaction between different soil zones along the pipe. Some studies in the past including an experimental study by the authors have shown the importance of cross effects between axial and lateral soil restraints on the pipeline during oblique axial/lateral pipeline/soil relative movements. In this numerical study a three-dimensional continuum finite element model is developed using ABAQUS/Standard software. The model has been calibrated against the centrifuge tests conducted by the authors. The numerical model successfully reproduces the ultimate loads and also the shape of failure surfaces observed during physical tests. The numerical model will be used to extend the physical investigation results by parametric studies in future works.

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