scholarly journals Using Continuum-Discontinuum Element Method to Model the Foliation-Affected Fracturing in Rock Brazilian Test

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qunlei Zhang ◽  
Zihan Zhi ◽  
Chun Feng ◽  
Ruixia Li ◽  
Jinchao Yue ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Stress Concentration ◽  
Rock Sample ◽  
Brazilian Test ◽  
Rock Matrix ◽  
Rock Fracturing ◽  
Anisotropic Rock ◽  
Disk Model ◽  
Simulation Results ◽  
Element Method

In this study, the continuum-discontinuum element method (CDEM) was used to investigate the tensile fracture mechanism of rock materials. An isotropic rock disk model and models considering different foliation inclinations were established, and three schemes were used to simulate the rock fracturing in Brazilian test. Then, the influences of the rock matrix and foliation strengths on anisotropy rock fracturing were investigated. Furtherly, simulation results were verified, and the rock fracture mechanisms were discussed. The results show that the rock fracturing in Brazilian test can be accurately simulated by CDEM, which is in accordance with the experimental results. For isotropic and horizontal foliation rock, the stress concentration in loading positions causes a local fracture of rock sample, and application of a local strengthening scheme can simulate the integral tension fracture of sample middle. As the foliation angle varies from 15° to 45°, the rock fracturing is affected by the stress concentration and foliation distribution. In splitting simulation, a strengthening scheme should be adopted to overcome this influence. As a result, the rock sample generates the sliding and compression-shear fracture. As the foliation angle changes from 45° to 75°, the foliation, rather than the matrix, dominates the fracture behavior of rock sample. For vertical foliations’ rock, as the middle foliation thickness is appropriately broadened, the simulation results are reasonable. In general, the tensile strength of anisotropic rock entirely decreases with an increase of foliation angle, and the effect of foliation strength on the tensile strength rock sample is larger than that of the rock matrix.

scholarly journals CURRENT COGNITION OF ROCK TENSILE STRENGTH TESTING BY BRAZILIAN TEST

2015 ◽  
Vol 30 (2) ◽  
pp. 101-114 ◽  
Author(s):  
Zlatko Briševac ◽  
◽  
Trpimir Kujundžić ◽  
Sandi Čajić ◽  
◽  
...  
Keyword(s):  
Tensile Strength ◽  
Brazilian Test ◽  
Strength Testing

Influence of Stress Concentration on Fatigue Property of Welded Joints of 5083 Aluminum Alloy

2013 ◽  
Vol 456 ◽  
pp. 451-455
Author(s):  
Jun Yang ◽  
Bo Li ◽  
Qiang Jia ◽  
Yuan Xing Li ◽  
Ming Yue Zhang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
Welded Joints ◽  
Weld Zone ◽  
Fatigue Property ◽  
Concentration Coefficient ◽  
5083 Aluminum Alloy ◽  
Stress Concentration Coefficient

Fatigue test of the welded joint of 5083 aluminum alloy with smooth and height of specimen and the weld zone than the high test measurement and theoretical stress concentration coefficient calculation, the weld reinforcement effect of stress concentration on the fatigue performance of welded joints. The results show that: Smooth tensile strength of specimens for 264MPa, fatigue strength is 95MPa, the tensile strength of the 36%. Higher tensile strength of specimens for 320MPa, fatigue strength is 70MPa, the tensile strength of the 22%. Higher specimen stress concentration coefficient is 1.64, the stress concentration to the weld toe becomes fatigue initiation source, and reduces the fatigue strength and the fatigue life of welded joints.

Numerical Simulation of the Stress Field of Thick 7B04 Aluminum Alloy Board during Continuous Manufacture Procedure

2007 ◽  
Vol 127 ◽  
pp. 259-264
Author(s):  
Hong Yuan Fang ◽  
Cheng Iei Fan
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Stress Concentration ◽  
Stress Field ◽  
Solution Treatment ◽  
Simulation Method ◽  
The Core ◽  
Manufacturing Procedure ◽  
Continuous Manufacture ◽  
Simulation Results

Numerical simulation method is employed in the article to analyze the stress field of thick 7B04 aluminum alloy board during manufacturing procedure of solution treatment, calendaring and stretching. The simulation results show that the surface of the board endures compressive stress while the core segment endures tensile stress, and the distribution of the stress is very inhomogeneous. The calendaring procedure helps to decrease the stress and redistribute the stress uniformly, but it also leads to stress concentration at the two ends of the board, which engenders bad influence on the subsequent processing. The board deforms plastically when being stretched, thus the stress decreases greatly and is redistributed uniformly.

Effects of Thermal Treatment on Tensile Strength of Laurentian Granite Using Brazilian Test

2015 ◽  
Vol 48 (6) ◽  
pp. 2213-2223 ◽  
Author(s):  
Tubing Yin ◽  
Xibing Li ◽  
Wenzhuo Cao ◽  
Kaiwen Xia
Keyword(s):  
Tensile Strength ◽  
Thermal Treatment ◽  
Brazilian Test

scholarly journals Simulation-based Prediction of Structural Design Failure in Fishing Deck Machinery a Hydraulic Type with Finite Element Method

2019 ◽  
Vol 130 ◽  
pp. 01001
Author(s):  
Agri Suwandi ◽  
Dede Lia Zariatin ◽  
Bambang Sulaksono ◽  
Estu Prayogi ◽  
I Made Widana
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Structural Design ◽  
Simulation Analysis ◽  
Poisson Ratio ◽  
Von Mises Stress ◽  
Material Base ◽  
Element Method

The fishing deck machinery is the tools used to collect fish in fishing activities. Fishing deck machinery is intended to improve the effectiveness of fishing operations. The mission of the Ministry of Marine Affairs and Fishery Year 2015-2019 in the Regulation of the Minister of Marine and Fisheries No. 45/PERMEN-KP/2015 which is a priority is to provide assistance for fishing facilities for fishermen; it is necessary to develop and optimize fishing deck machinery. To assure the safety and dependability of these fishing deck machinery, calculations, simulation and functional tests are needed. This paper discusses the prediction of structural failure in the design of fishing deck machinery a hydraulic type with finite element method simulation approach. The results of the FEM simulation analysis are (i) the maximum value of von-Mises stress is greater than the ultimate tensile strength of the material; (ii) 1st principal stress value minimum is smaller than the ultimate tensile strength of material; (iii). the Poisson ratio value higher than the Poisson ratio value of the material. Base on the simulation result, the structural design of fishing deck machinery is safety.

A study of azimuthal electromagnetic wave LWD based on self-adaptive hp finite element method

2018 ◽  
Vol 32 (34n36) ◽  
pp. 1840073
Author(s):  
Hui Li ◽  
Yi-Bo Jiang ◽  
Jian-Wen Cai
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Electromagnetic Wave ◽  
Real Time ◽  
Simulation Results ◽  
Peak Value ◽  
Element Method ◽  
Self Adaptive ◽  
Hp Finite Element

Azimuthal electromagnetic wave logging-while-drilling (LWD) technology can detect weak electromagnetic wave signal and realize real-time resistivity imaging. It has great values to reduce drilling cost and increase drilling rate. In this paper, self-adaptive hp finite element method (FEM) has been used to study the azimuthal resistivity LWD responses in different conditions. Numerical simulation results show that amplitude attenuation and phase shift of directional electromagnetic wave signals are closely related to induced magnetic field and azimuthal angle. The peak value and polarity of geological guidance signals can be used to distinguish reservoir interface and achieve real-time geosteering drilling. Numerical simulation results also show the accuracy of the self-adaptive hp FEM and provide physical interpretation of peak value and polarity of the geological guidance signals.

A Tunable THz Plasmonic Waveguide Based on Graphene Coated Bow-tie Nanowire with High Mode Confinement

2020 ◽  
Vol 12 ◽  
Author(s):  
Jue Wang ◽  
Tao Ma ◽  
Xu Wang ◽  
Fang Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Field ◽  
High Density ◽  
Plasmonic Waveguide ◽  
Field Distributions ◽  
Simulation Results ◽  
Photonic Circuit ◽  
Bow Tie ◽  
Element Method

Background: : A THz Plasmonic Waveguide Based on Graphene Coated Bow-tie Nanowire (TPW-GCBN) is proposed. The waveguide characteristics are investigated by using Finite Element Method (FEM). The influence of the geometric parameters on propagation constants, electric field distributions, effective mode areas, and propagation lengths are obtained numerically. The performance tunability of TPW-GCBN is also studied by adjusting the Fermi energy (FE). The simulation results show that the TPW-GCBN has better mode confinement ability. The TPW-GCBN has potential applications in high density integration of photonic circuit for the future tunable micro nano optoelectronic devices. Surface plasmon polaritons (SPPs) based waveguides have been widely used to enhance the local electric fields. It also has the capability of manipulating electromagnetic fields on the deep-subwavelength. Objective:: The waveguide characteristics of a THz Plasmonic Waveguide Based on Graphene Coated Bow-tie Nanowire (TPW-GCBN) should be investigated. The tunability of TPW-GCBN should be studied by adjusting the chemical potential (FE) which can be changed by the voltage. Method: : The mode analysis and parameter sweep in Finite Element Method (FEM) were used to simulate the TPW-GCBN for analyzing effective refractive index (neff), electric field distributions, normalized mode areas (Am), propagation length (Lp) and figure of merit (FoM). Results: : At 5 THz, Aeff of λ2/14812, Lp of ~2 μm and FoM of 25 can be achieved. The simulation results show that the TPW-GBN has good mode confinement ability and flexible tunability. Conclusion:: The TPW-GBN provides a new freedom to manipulate the graphene surface plasmons, and leads to new applications in high density integration of photonic circuit for tunable integrated optical devices.

Dynamic tensile process of blended fabric using finite element method

2020 ◽  
Vol 32 (5) ◽  
pp. 707-724
Author(s):  
Xuzhong Su ◽  
Xinjin Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Experimental Testing ◽  
Woven Fabrics ◽  
Weft Yarn ◽  
Tensile Fracture ◽  
Content Type ◽  
Tensile Process ◽  
Simulation Results ◽  
Element Method

PurposeTensile property is one basic mechanics performance of the fabric. In general, not only the tensile values of the fabric are needed, but also the dynamic changing process under the tension is also needed. However, the dynamic tensile process cannot be included in the common testing methods by using the instruments after fabric weaving.Design/methodology/approachBy choosing the weft yarn and warp yarn in the fabric as the minimum modeling unit, 1:1 finite element model of the whole woven fabrics was built by using AutoCAD software according to the measured geometric parameters of the fabrics and mechanical parameters of yarns. Then, the fabric dynamic tensile process was simulated by using the ANSYS software. The stress–strain curve along the warp direction and shrinkage rate curve along the weft direction of the fabrics were simulated. Meanwhile, simulation results were verified by comparing to the testing results.FindingsIt is shown that there are four stages during the fabric tensile fracture process along the warp direction under the tension. The first stage is fabric elastic deformation. The second stage is fabric yield deformation, and the change rate of stress begins to slow down. The third stage is fiber breaking, and the change of stress fluctuates since the breaking time of the fibers is different. The fourth stage is fabric breaking.Originality/valueIn this paper, the dynamic tensile process of blended woven fabrics was studied by using finite element method. Although there are differences between the simulation results and experimental testing results, the overall tendency of simulation results is the same as the experimental testing results.

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