scholarly journals Finite Element Simulation of Multi-Scale Bedding Fractures in Tight Sandstone Oil Reservoir

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 131 ◽  
Author(s):  
Qianyou Wang ◽  
Yaohua Li ◽  
Wei Yang ◽  
Zhenxue Jiang ◽  
Yan Song ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Principal Stress ◽  
Oil And Gas ◽  
Maximum Principal Stress ◽  
Critical Parameters ◽  
Yanchang Formation ◽  
Multi Scale ◽  
Element Simulation ◽  
Minimum Principal Stress

Multi-scale bedding fractures, i.e., km-scale regional bedding fractures and cm-scale lamina-induced fractures, have been the focus of unconventional oil and gas exploration and play an important role in resource exploration and drilling practice for tight oil and gas. It is challenging to conduct numerical simulations of bedding fractures due to the strong heterogeneity without a proper mechanical criterion to predict failure behaviors. This research modified the Tien–Kuo (T–K) criterion by using four critical parameters (i.e., the maximum principal stress (σ1), minimum principal stress (σ3), lamina angle (θ), and lamina friction coefficient (μlamina)). The modified criterion was compared to other bedding failure criteria to make a rational finite element simulation constrained by the four variables. This work conducted triaxial compression tests of 18 column samples with different lamina angles to verify the modified rock failure criterion, which contributes to the simulation work on the multi-scale bedding fractures in the statics module of the ANSYS workbench. The cm-scale laminated rock samples and the km-scale Yanchang Formation in the Ordos Basin were included in the multi-scale geo-models. The simulated results indicate that stress is prone to concentrate on lamina when the lamina angle is in an effective range. The low-angle lamina always induces fractures in an open state with bigger failure apertures, while the medium-angle lamina tends to induce fractures in a shear sliding trend. In addition, the regional bedding fractures of the Yanchang Formation in the Himalayan tectonic period tend to propagate under the conditions of lower maximum principal stress, higher minimum principal stress, and larger stratigraphic dip.

scholarly journals Modeling the influence of connecting elements in wood products behavior: a numerical multi-scale approach

2018 ◽  
Vol 19 (3) ◽  
pp. 301 ◽  
Author(s):  
Luc Chevalier ◽  
Heba Makhlouf ◽  
Benoît Jacquet-Faucillon ◽  
Eric Launay
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Failure Process ◽  
Numerical Procedure ◽  
Wood Products ◽  
Image Correlation ◽  
Bending Test ◽  
3D Finite Element ◽  
Multi Scale ◽  
Element Simulation

Wood furniture is often composed of simple parts that may be modeled as beams or plates. These particularities allow using simplified approaches that reduces the number of degrees of freedom (dof for short) in a finite element simulation of the furniture's behavior. Generally, connections are not taken into account in such simulations but these connections are critical in the failure process of the furniture and it worth studying it precisely. Using a multi-scale approach, this paper introduces a numerical procedure to identify the connection contribution in the furniture's stiffness. Comparing 3D finite element calculations with a Timoshenko's beam calculation on a corner of two wooden parts, we identify the specific behavior of the connection elements (pins, nut, screw… and local 3D effects) to introduce it as a punctual 0D element in the beam code. Two validations of the approach are presented here: (i) a numerical validation by comparing the result of the beam code with a complete 3D finite element simulation on a representative plane structure of wooden furniture; (ii) an experimental validation by managing a global bending test and measuring the displacement field using digital image correlation (DIC for short).

Individual-specific multi-scale finite element simulation of cortical bone of human proximal femur

2013 ◽  
Vol 244 ◽  
pp. 298-311 ◽  
Author(s):  
Maria-Grazia Ascenzi ◽  
Neal P. Kawas ◽  
Andre Lutz ◽  
Dieter Kardas ◽  
Udo Nackenhorst ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Cortical Bone ◽  
Proximal Femur ◽  
Multi Scale ◽  
Element Simulation

scholarly journals Evaluation of the stress distribution in the cortical bone caused by variations in implant applications in patients with bruxism: A three-dimensional finite element analysis

2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 194-200
Author(s):  
Yakup Kantaci ◽  
Sabiha Zelal Ülkü
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Cortical Bone ◽  
Principal Stress ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Element Analysis ◽  
Minimum Principal Stress ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Aim: To evaluate the stress distribution in the cortical bone under parafunctional forces with different occlusal thicknesses, monolithic zirconia with different implant diameters, and number variations in implant-supported fixed prosthetic restorations applied in patients with bruxism. Methodology: The tomographic sections of the previously registered mandible were used in order to model the mandible. Modeled bone height is 30 mm, cortical bone thickness is 1.5 mm, and trabecular bone thickness is modeled as 13 mm. By placing two implants in the created bone model, a three-member main model (Group 1), the number of implants was increased, three implants supported the Group 2 models, the diameter of the implants was increased, and the Group 3 models were created. The created Group 1, 2, 3 models, the occlusal thickness was divided into subgroups with 1.0, 1.5, and 2.0 mm, respectively (Groups A, B, and C). The groups were applied in two directions: vertical and 30o oblique. Stress values under forces were analyzed by finite element stress analysis. Results: Under vertical loading, the maximum principal stress value in the cortical bone was found to be lowest in Group 2C, and the highest maximum principal stress value was found in Group 1A. The minimum principal stress value in the cortical bone was found to be the lowest in Group 3C, and the highest minimum principal stress value was found in Group 1A. Under oblique loading, the maximum principal stress value in the cortical bone was found to be the lowest in Group 3C and the highest maximum principal stress value was found in Group 1A. The minimum principal stress value in the cortical bone was found to be lowest in Group 3C, and the highest minimum principal stress value was found in Group1A. Conclusion: Stresses caused by oblique forces are more than vertical forces. Increasing the occlusal thickness of the implant fixed prosthesis material, implant diameter, and number reduce the minimum and maximum principal stress values in the cortical   How to cite this article: Kantaci Y, Ülkü SZ. Evaluation of the stress distribution in the cortical bone caused by variations in implant applications in patients with bruxism: A three-dimensional finite element analysis. Int Dent Res 2021;11(Suppl.1):194-200. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.27   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

scholarly journals Formation of Arbitrary Patterns in Ultraviolet Cured Polymer Film via Electrohydrodynamic Patterning

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Xin Li ◽  
Yucheng Ding ◽  
Jinyou Shao ◽  
Hongmiao Tian ◽  
Hongzhong Liu
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Polymer Film ◽  
Applied Voltage ◽  
Great Influence ◽  
Critical Parameters ◽  
High Fidelity ◽  
Field Coupling ◽  
Element Simulation ◽  
Electrohydrodynamic Patterning

Electrohydrodynamic patterning of arbitrary patterns is achieved by optimizing the critical parameters (applied voltage and spacer height). The applied voltage has a great influence on the fidelity of L-shaped line structures with different sizes. The L-shaped line structures with high fidelity are obtained by using the moderate applied voltage. The spacer height has a great influence on the fidelity of square structures with different sizes. The square structures with high fidelity are obtained by using the low height spacer. The multi-field coupling transient finite element simulation demonstrates that the lack of polymer owing to the high height spacer leads to the formation of defects.

scholarly journals Finite Element Simulation of Oil and Gas Reservoir In Situ Stress Based on a 3D Corner-point Grid Model

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Liu Yuyang ◽  
Liu Shiqi ◽  
Pan Mao
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Finite Element Simulation ◽  
Oil And Gas ◽  
Corner Point ◽  
In Situ Stress ◽  
Grid Model ◽  
Conversion Algorithm ◽  
Element Simulation

A three-dimensional (3D) corner-point grid model gives a relatively accurate description of the structural properties and spatial distribution of oil and gas reservoirs than Cartesian grids. The finite element simulation of the stress field provides a relatively probable presentation of the in situ stress distribution. Both methods are of great importance to the exploration and development of oil and gas fields. Implementing the finite element simulation of in situ stress on a 3D corner-point grid model not only retains the structural attributes of a reservoir but also allows the accurate simulation of the 3D stress distribution. In this paper, we present a method for implementing the finite element simulation of in situ stress based on a 3D corner-point grid model. We first established a fine 3D reservoir model with corner-point grids and then converted the grids into corresponding 3D finite element grid models using a grid conversion algorithm. Next, we simulated the in situ stress distribution with the finite element method. The stress model is then resampled to corresponding corner-point grid geological models using the reverse algorithm. The grid conversion algorithm is to provide data support for the subsequent numerical simulation and other research efforts, thereby guaranteeing procedure continuity and data consistency. Finally, we simulated the stress distribution of a real oil field, the X region. Comparing the simulated result with the measured result, the high agreement validated the effectiveness and accuracy of the proposed method.

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