scholarly journals Peridynamic Model for the Numerical Simulation of Anchor Bolt Pullout in Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jiezhi Lu ◽  
Yaoting Zhang ◽  
Habib Muhammad ◽  
Zhijun Chen
Keyword(s):  
Plain Concrete ◽  
Experimental Investigations ◽  
Anchor Bolt ◽  
Short Range Force ◽  
Peridynamic Model ◽  
Anchoring System ◽  
Pullout Load ◽  
Level Model ◽  
Crack Paths ◽  
Remeshing Algorithm

Predictive simulation of anchor pullout from concrete structures is not only a serious problem in structural mechanics but also very important in structural design safety. In the finite element method (FEM), the crack paths or the points of crack initiation usually need to be assumed in advance. Otherwise, some special crack growth treatment or adaptive remeshing algorithm is normally used. In this paper, an extended peridynamic method was introduced to avoid the difficulties found in FEM, and its application on anchor bolt pullout in plain concrete is studied. In the analysis, the interaction between the anchor bolt and concrete is represented by a modified short-range force and an extended bond-level model for concrete is developed. Numerical analysis results indicate that the peak pullout load obtained and the crack branching of the anchoring system agreed well with the experimental investigations.

Test on Corrosion Resistance of GFRP Anchor Bolt

2012 ◽  
Vol 535-537 ◽  
pp. 1927-1935 ◽  
Author(s):  
Xiao Yong Luo ◽  
Xie Xing Tang ◽  
Kai Lei Li ◽  
Ya Chuan Kuang
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Loss Rate ◽  
Mechanical Performance ◽  
Effective Means ◽  
Anchor Bolt ◽  
Geological Conditions ◽  
Anchoring System ◽  
Anchor Bolts ◽  
Corrosion Time

Steel is commonly used as the materials of anchor bolts in permanent anchoring works. The nature the steel anchor bolt easy to be corroded, however, poses a serious potential safety hazard to the anchoring system mainly including steel anchor bolts. To use GFRP(glass fiber reinforced polymer) anchor bolts instead of reinforcing bars is an effective means to deal with corrosion. Based on the test of accelerating aging in high solubility, the physical and mechanical performance tests are conducted on GFRP bolts in normal, acid, alkalis and salt conditions, from which the change law of physical and mechanical property can be studied for bolts in different corrosion conditions. As shown from the test results, the weight of GFRP bolt is reduced after it is corroded and the rate of weight loss increases as the corrosion time extends. Thick swelling can be seen on bolts in alkalis conditions. Loss rate of tensile strength and increase rate of elastic modulus are greater in alkalis conditions than in acid conditions, the former reaching 13.76% and the latter 9.83%. As for bolts in acid conditions, tensile strength decreases as the corrosion time extends while the rate and amount of loss is less than that of bolts in acid and alkalis conditions. The tensile strength decreases as the solubility of corrosion solution increases. The loss rate of tensile strength is the most for bolts in alkalis conditions; it comes second in acid conditions and the least in salt conditions. The elastic modulus of bolts in acid conditions and alkalis conditions increases while the rate is comparatively low as the solubility gets higher. Elastic modulus of bolts in salt conditions decreases as the solubility rises with lower rate and smaller amount of loss. These results supply test foundation for application of GFRP bolts in complicated geological conditions.

Experimental verification of a constitutive model for concrete cracking

2001 ◽  
Vol 215 (2) ◽  
pp. 75-86 ◽  
Author(s):  
B Winkler ◽  
G Hofstetter ◽  
G Niederwanger
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Ultimate Load ◽  
Plain Concrete ◽  
Experimental Investigations ◽  
Reinforced Concrete Structures ◽  
Structural Members ◽  
Concrete Cracking ◽  
Smeared Crack Approach ◽  
Smeared Crack

A constitutive model for concrete cracking, based on the smeared crack approach within the framework of the theory of plasticity, was verified by experiments on L-shaped structural members. The model is used for finite element ultimate load analyses of plain and reinforced concrete structures. The experimental investigations consisted of a series of L-shaped structural members, made of plain concrete and three series of reinforced L-shaped structural members with different layout of the reinforcement, which were loaded until failure. The comparison between experimental and computed results included the load at the initiation of cracking and the load-displacement curves in the pre- and post-peak regions. Additionally, the experimentally determined crack patterns were compared with the computed crack propagation and damage behaviour of the material.

Quasi-Static Simulation of Crack Growth in Elastic Materials Considering Internal Boundaries and Interfaces

2012 ◽  
Vol 525-526 ◽  
pp. 181-184 ◽  
Author(s):  
P. Judt ◽  
Andreas Ricoeur
Keyword(s):  
Crack Growth ◽  
Cohesive Zone Model ◽  
Zone Model ◽  
Fe Method ◽  
Material Interfaces ◽  
Linear Elastic ◽  
Elastic Bodies ◽  
Elastic Fracture ◽  
Crack Paths ◽  
Remeshing Algorithm

This work presents numerical methods used for predicting crack paths in technicalstructures based on the theory of linear elastic fracture mechanics. The FE-method is usedin combination with an efficient remeshing algorithm to simulate crack growth. A post pro-cessor providing loading parameters such as the J-integral and stress intensity factors (SIF) ispresented. Path-independent contour integrals are used to avoid special requirements concern-ing crack tip meshing and to enable efficient calculations for domains including interfaces andinternal boundaries. In particular, the interaction of cracks and internal boundaries and inter-faces is investigated. The simulation combines crack propagation within elastic bodies and atbi-material interfaces. The latter is based on a cohesive zone model. The presented numericalresults of crack paths are verified by experiments.

scholarly journals Simulation of chemo-thermo-mechanical problems in cement-based materials with Peridynamics

Meccanica ◽  
2021 ◽  
Author(s):  
Soheil Bazazzadeh ◽  
Marco Morandini ◽  
Mirco Zaccariotto ◽  
Ugo Galvanetto
Keyword(s):  
Thermal Equilibrium ◽  
Early Age ◽  
Mechanical Problem ◽  
Hydration Degree ◽  
Peridynamic Model ◽  
Cement Based Materials ◽  
Thermal Equilibrium Condition ◽  
Crack Paths ◽  
Fully Coupled ◽  
Good Agreement

AbstractA chemo-thermo-mechanical problem is solved using a peridynamic approach to investigate crack propagation in non-reinforced concrete at early-age. In the present study, the temperature evolution and the variation of the hydration degree in conjunction with the mechanical behaviour of cement-based materials are examined. Firstly, a new peridynamic model is introduced to solve fully coupled chemo-thermal problems by satisfying thermal equilibrium condition and hydration law simultaneously and then the effects of the chemo-thermal analysis are imposed in the mechanical framework to investigate all the interactions. The proposed approach is used to solve 2D chemo-thermo-elastic problems and then it is applied to investigate the fracture of concrete structures. Additionally, we examine the accuracy of the method by comparing the crack paths, temperature and hydration degree with those achieved by applying other numerical methods and the experimental data available in the literature. A good agreement is obtained between all sets of results.

Model investigation of the performance of single anchors and groups of anchors

1994 ◽  
Vol 31 (2) ◽  
pp. 273-284 ◽  
Author(s):  
Ashraf Ghaly ◽  
Adel Hanna
Keyword(s):  
Failure Mechanism ◽  
Load Distribution ◽  
Dense Medium ◽  
Unit Weight ◽  
Experimental Investigations ◽  
Experimental Setup ◽  
Uplift Capacity ◽  
Sand Surface ◽  
Pullout Load ◽  
Upward Displacement

Experimental investigations on the performance of single and groups of vertical screw anchors installed in dense, medium, and loose sands are presented. An experimental setup was instrumented to allow the measurement of the total pullout load, upward displacement, sand surface deflection, and stress development in the sand layer during all phases of testing. A sand placing technique was developed and utilized over all the testing program to ensure reproducibility of the predetermined unit weight. Stresses measured within sand deposits indicated that the tested sands were overconsolidated due to the application of mechanical compaction. Special tests were conducted on colored–layered sand to define the nature of the failure mechanism. The results of these tests, together with the measurements of the deflection of the sand surface, were employed to establish the shape of the rupture surface which could be represented by a segment of a logarithmic spiral. Groups of three, four, six, and nine anchors were tested in this investigation. The effect of installation depth, spacing between anchors, and sand characteristics on the ultimate pullout load of the group was examined. The experimental setup was instrumented to allow the measurement, of the total pullout load of the group as well as that of individual anchors in the group. Load distribution among the anchors of a group is discussed in terms of anchor location and the applied load level. At failure, all anchors contribute almost equally to the uplift capacity. Group efficiencies were calculated and compared. An installation procedure was proposed to avoid differential upward displacement during the uplifting process and to provide uniform load distribution on the different anchors of the group. Key words : anchors, failure mechanism, group action, model tests, sand, uplift capacity.

Dynamic Brittle Fracture Captured With Peridynamics

2011 ◽  
Author(s):  
Youn D. Ha ◽  
Florin Bobaru
Keyword(s):  
Brittle Fracture ◽  
Crack Path ◽  
Process Zone ◽  
Stress Waves ◽  
Crack Branching ◽  
Peridynamic Model ◽  
Branching Angle ◽  
Dynamic Brittle Fracture ◽  
Crack Paths ◽  
Secondary Cracking

The bond-based peridynamic model is able to capture many of the essential characteristics of dynamic brittle fracture observed in experiments: crack branching, crack-path instability, asymmetries of crack paths, successive branching, secondary cracking at right angles from existing crack surfaces, etc. In this paper we investigate the influence of the stress waves on the crack branching angle and the velocity profile. We observe that crack branching in peridynamics evolves as the phenomenology proposed by the experimental evidence [1]: when a crack reaches a critical stage (macroscopically identified by its stress intensity factor) it splits into two or more branches, each propagating with the same speed as the parent crack, but with a much reduced process zone.

scholarly journals Failure Evolution Law of Reinforced Anchor System under Pullout Load Based on DIC

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yue Li ◽  
Chongming Gao ◽  
Qian Li ◽  
Qiqi Wu ◽  
Wenjun Meng
Keyword(s):  
Image Correlation ◽  
Test Model ◽  
Evolution Law ◽  
Anchor System ◽  
Steel Bar ◽  
Force Transfer ◽  
Failure Evolution ◽  
Anchoring System ◽  
Pullout Load ◽  
Pulling Force

To obtain the failure evolution law, a pullout test model of the anchor system is proposed based on the digital image correlation (DIC) measurements. By the study of the displacement field, the strain field, and the force transfer law of the anchor system under the pulling load, the failure law of the anchor system is revealed. The results show that (1) the failure mode and the ultimate bearing capacity of the anchor system are related to the thickness of the anchor agent; (2) in the anchor system, the pulling force is gradually transferred from the loading end to the free end along the steel bar, and the greater the thickness of the anchoring agent, the deeper the transfer range; (3) during the loading, the deformation of the anchoring system is mainly concentrated at the interface between the anchoring agent and the concrete and expands to the depth along the steel bar; and (4) the failure evolution rate of the anchorage system is related to the loading stage. The failure evolution of the anchor system can be divided into the elastic phase, the plastic phase, and the deformation rebound phase.

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