检索结果-内蒙古大学图书馆

Time-domain finite element method based on arbitrary quadrilateral meshes for two-dimensional SHTE mode seismoelectric and electroseismic waves modelling

引用

GEOPHYSICAL PROSPECTING 2024年第6期72卷 2419-2438页

作者： Li, Jun Yin, Changchun Liu, Yunhe Huang, Xianyang Zhang, Bo Ren, Xiuyan Su, Yang Wang, Luyuan Ma, Xinpeng Jilin Univ Coll Geoexplorat Sci & Technol Changchun 130026 Peoples R China

A time-domain finite-element method based on an arbitrary quadrilateral mesh is proposed to simulate two dimensional seismoelectric and electroseismic waves in SHTE mode. By decoupling the electrokinetic coupling equation, we can solve seismic waves and electromagnetic waves independently. For the simulation of seismic wavefield, we utilize a more compact second-order unsplit perfectly matched layer that is easier to implement in finite-element methods. Moreover, to avoid errors caused by the quasi-static approximation, we directly solve the full-wave electromagnetic equations when simulating the electromagnetic wavefield. Our computational domain is discretized using arbitrary quadrilateral meshes, which offers possibilities in handling undulating terrain and complex anomalies in the underground. To ensure computational accuracy, we utilized biquadratic interpolation as our finite-element basis functions, which provides higher precision compared to bilinear interpolation. We validate our time-domain finite-element method by comparing its results with analytical solutions for a layered model. We also apply our algorithm to the modelling of an underground aquifer and a complex anomalous hydrocarbon reservoir under undulating terrain.

关键词： arbitrary quadrilateral mesh finite-element method numerical modelling seismoelectric and electroseismic wave propagation

来源：评论

学校读者我要写书评

暂无评论

Process Pipeline Strength Calculation methodology Enhancement Using finite-element method

引用

JOURNAL OF PIPELINE SYSTEMS ENGINEERING AND PRACTICE 2023年第2期14卷 04023013-04023013页

作者： Zavyalov, Alexey Zhuchkov, Konstantin Vasilchenko, Mikhail Natl Univ Oil & Gas Gubkin Univ Dept Thermodynam & Heat Engines 65Bld 1 Leninsky Prospekt Moscow 119991 Russia Royal Melbourne Inst Technol RMIT Univ Sch Engn GPO Box 2476 Melbourne Vic 3001 Australia

The paper analyzes possible approaches to the technical evaluation of the process pipelines according to the diagnostic results using strength calculation based on the finite-element method. Process pipelines have a complex dimensional configuration and a complex stress-strain state, so traditional approaches to technical diagnostics and assessment of the technical condition of main pipelines are not applicable. Qualities of the process pipelines as objects bring relevance to the development of the practical approaches to its numerical modeling and formalization of boundary and loading conditions when using software systems based on the finite-element method. This paper presents the results of experimental studies of the stress-strain state of a number of test benches simulating elements of pipeline structures. Therefore, analytical research is presented that allows recommendations to be formulated for the numerical modeling of the process pipelines. The formulated recommendations allow us to correctly simulate process pipelines when calculating their stress-strain state using the finite-element method to model the conditions of fastening and loading, thereby ensuring high accuracy of the assessment of the technical condition of structures based on the results of their diagnostics.

关键词： Process pipelines Reliability Strength Stress-strain state Technical diagnosis finite-element method

来源：评论

学校读者我要写书评

暂无评论

Analysis of the Stress-Strain State of a Bridgman Specimen in Axial Tension by the finite-element method

引用

MATERIALS SCIENCE 2021年第5期56卷 722-726页

作者： Lenkovskyi, T. M. Ivanytskyi, Ya L. Molkov, Yu, V Duriagina, Z. A. Kulyk, V. V. Trostianchyn, A. M. Shyshkovskyi, R. O. Natl Acad Sci Ukraine Karpenko Physicomech Inst Lvov Ukraine Lviv Polytech Inst Natl Univ Lvov Ukraine John Paul II Catholic Univ Lublin Lublin Poland

We develop a finite-element three-dimensional model of a Bridgman specimen with an aim to investigate its elastoplastic deformation in tension. The distribution of stresses in the cross section of the working part of the specimen for a wide range of loads is determined. It is shown that stresses acting at the center of the specimen in the stage of elastic deformation are lower than the stresses on its surface and, on the contrary, higher than the stresses in the stage of elastoplastic deformation. For a specimen made of 40Kh steel, we find a tensile force for which the normal stresses formed in its cross-section are uniform.

关键词： Bridgman specimen finite-element method elastoplastic deformation 40Kh steel true stresses

来源：评论

学校读者我要写书评

暂无评论

Effects of mechanical vibration on designed steel-based plate geometries: behavioral estimation subjected to applied material classes using finite-element method

引用

CURVED AND LAYERED STRUCTURES 2021年第1期8卷 225-240页

作者： Lenggana, Bhre Wangsa Prabowo, Aditya Rio Ubaidillah, Ubaidillah Imaduddin, Fitrian Surojo, Eko Nubli, Haris Adiputra, Ristiyanto Univ Sebelas Maret Dept Mech Engn Surakarta Indonesia Pukyong Natl Univ Interdisciplinary Program Marine Convergence Desi Busan South Korea Kyushu Univ Dept Marine Syst Engn Fukuoka Japan

A research subject in structural engineering is the problem of vibration under a loading object. The two-dimensional (2D) model of a structure under loading is an example. In general, this case uses an object that is given a random frequency, which then causes various changes in shape depending on the frequency model. To determine the difference in performance by looking at the different forms of each mode, modal analysis with ANSYS was used. The samples to be simulated were metal plates with three variations of the model, namely, a virgin metal plate without any holes or stiffness, plates with given holes, and metal plates with stiffness on one side. The model was simulated with modal analysis, so that 20 natural frequencies were recorded. The sample also used different materials: low-carbon steel materials (AISI 304), marine materials (AISI 1090), and ice-class materials (AR 235). Several random-frequency models proved the deformation of different objects. Variations of sheet-metal designs were applied, such as pure sheet metal, giving holes to the sides, and stiffening the simulated metal sheet.

关键词： modal analysis random vibration designed plate steel class finite-element method

来源：评论

学校读者我要写书评

暂无评论

3D Airborne EM Forward Modeling Based on finite-element method with Goal-Oriented Adaptive Octree Mesh

引用

REMOTE SENSING 2023年第11期15卷 2816-2816页

作者： Han, Xue Ni, Jianfu Yin, Changchun Zhang, Bo Huang, Xin Zhu, Jiao Liu, Yunhe Ren, Xiuyan Su, Yang Jilin Univ Coll Geoexplorat Sci & Technol Changchun 130026 Peoples R China Yangtze Univ Key Lab Explorat Technol Oil & Gas Resources Wuhan 430100 Peoples R China China Univ Min & Technol Sch Resources & Geosci Xuzhou 221116 Peoples R China

The finite-element (FE) method for three-dimensional (3D) airborne electromagnetic (AEM) modeling can flexibly simulate complex geological structures at high accuracy. However, it has low efficiency and high computational requirements. To solve these problems, one needs to generate meshes more reasonably. In view of this, we develop an adaptive octree meshing scheme for frequency-domain AEM modeling. The octree meshes have the characteristics of regularity and flexibility, while the adaptive algorithm can effectively refine the mesh locally. In our adaptive mesh generation, the posterior errors and weighted coefficients are used to construct the final weighted posterior errors. We verify the accuracy of our method by comparing its results with semi-analytical solutions for a half-space model. Furthermore, we use the spectral-element (SE) method and our method to calculate EM responses for an abnormal block model and compare their computational costs. The results show that our adaptive scheme has obviously technical advantages over SE method for AEM modeling with multiple frequencies and multiple survey stations. Finally, we calculate a model with complex geological structures to verify the feasibility of our algorithm in complex geological circumstances.

关键词： airborne EM frequency domain 3D forward modeling finite-element method adaptive octree mesh

来源：评论

学校读者我要写书评

暂无评论

Optimizing mechanical behavior of middle ear prosthesis using finite element method with material degradation FGM in three functions

引用

MECHANICS OF ADVANCED MATERIALS AND STRUCTURES 2025年第3期32卷 478-487页

作者： Khatir, O. Fekih, S. M. Sahli, A. Boudjemaa, I. Benkhettou, A. Salem, M. Bouiadjra, B. Bachir Univ Djillali Liabes Sidi Bel Abbes Dept Mech Engn Lab Mech Phys Mat LMPM BP 89 Sidi Bel Abbes 22000 Algeria Univ Sci & Technol Oran Mohamed Boudiaf USTO MB Fac Mech Engn Oran Algeria

Advancements in technology have revolutionized healthcare, with notable impacts on auditory health. This study introduces a novel approach aimed at optimizing materials for middle ear prostheses to enhance auditory performance. We developed a finite element (FE) model of the ear incorporating a pure titanium TORP prosthesis, validated against experimental data. Subsequently, we applied Functionally Graded Materials (FGM) methodology, utilizing linear, exponential, and logarithmic degradation functions to modify prosthesis materials. Biocompatible materials suitable for auditory prostheses, including Stainless Steel, titanium, and Hydroxyapatite, were investigated. Our findings indicate that combinations such as Stainless Steel with titanium and Hydroxyapatite offer improved outcomes compared to pure titanium and Hydroxyapatite ceramic, in terms of both displacement and stress. Additionally, personalized prostheses tailored to individual patient needs are feasible, underscoring the potential for further advancements in auditory healthcare.

关键词： Middle ear prosthesis ossicles FGM vibration analysis finite-element method

来源：评论

学校读者我要写书评

暂无评论

Convergence Analysis of Non-conforming finite element method for a Quasi-static Contact Problem

引用

COMMUNICATIONS ON APPLIED MATHEMATICS AND COMPUTATION 2025年 1-27页

作者： Porwal, Kamana Wadhawan, Tanvi Indian Inst Technol Dept Math Delhi 110016 India

We analyze the numerical solution of a non-linear evolutionary variational inequality, which is encountered in the investigation of quasi-static contact problems. The study of this article encompasses both the semi-discrete and fully discrete schemes, where we employ the backward Euler method for time discretization and utilize the lowest order Crouzeix-Raviart non-conforming finite-element method for spatial discretization. By assuming appropriate regularity conditions on the solution, we establish a priori error analysis for these schemes, achieving the optimal convergence order for linear elements. To illustrate the numerical convergence rates, we provide numerical results on a two-dimensional test problem.

关键词： finite-element method A priori error estimates Variational inequalities Quasi-static problem Supremum norm

来源：评论

学校读者我要写书评

暂无评论

Numerical analysis of point-sharp indentation-load relaxation simulated using the finite-element method to characterize the power-law creep deformation of a visco-elastoplastic solid

引用

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES 2022年 238卷 111417-111417页

作者： Akatsu, Takashi Akimoto, Yoshihiro Sasaki, Ryo Shinoda, Yutaka Wakai, Fumihiro Saga Univ Fac Art & Reg Design 2441-1 Oono OtsuArita Cho Saga 8440013 Japan Tokyo Inst Technol Inst Innovat Res Lab Mat & Struct R3-24 4259 Nagatsuta Yokohama Kanagawa 2268503 Japan Ube Coll Natl Inst Technol 2-14-1 Tokiwadai Ube Yamaguchi 7558555 Japan

The modified indentation-load relaxation (ILR), i.e. indentation-stress relaxation (ISR), of point-sharp indentation on a visco-elastoplastic solid (VEPS) with the power-law creep deformation (PLCD) simulated using the finite-element method differs obviously from that on a linear VEPS because of (1) remarkable dwell time dependent piling-up around an indentation at constant indentation depth, (2) nonexponential ISR, and (3) a-dependent ISR rate, where Y and E are the yield stress and Young's modulus of the indented solid, respectively. Based on the numerical analysis of the characteristic ISR, a stepwise procedure is proposed to estimate the pre exponential creep constant and stress exponent of PLCD from an ILR test.

关键词： Nanoindentation Load relaxation Power-law creep finite-element method

来源：评论

学校读者我要写书评

暂无评论

Local wavefield refinement using Fourier interpolation and boundary extrapolation for finite-element method based on domain reduction method

引用

GEOPHYSICS 2022年第3期87卷 T251-T263页

作者： Zhang, Lei Zhang, Jinhai Chinese Acad Sci Inst Geol & Geophys Key Lab Earth & Planetary Phys Beijing Peoples R China Chinese Acad Sci Innovat Acad Earth Sci Beijing Peoples R China

The domain reduction method based on the finite-element method (FEM) is promising for multiscale seismic wave simulations for local complex structures and rough topography. However, a transition region is required to refine the wavefields from coarse to fine grids, which may lead to strong artifacts. Traditional wavefield interpolation methods can only handle a small upsampling ratio due to their low accuracy. Here, we interpolation and boundary extrapolation. It requires that the wavefield in the transition region is evenly sampled, which may slightly reduce the flexibility of FEMs. Fortunately, this constraint only exists in two layers of nodes, in which the coarse and fine grids are collocated. To further apply our interpolation method to the wavefield upsampling on the nonuniform grid, we adopt cubic interpolation within the local region of interest, which is adequate in accuracy for regularizing the wavefield on the fine nonuniform grid. For a topographic surface, we perform wavefield extrapolation on the ground surface to avoid abnormal amplitude variations below and beyond the surface, which can greatly reduce potential artifacts caused by the Fourier interpolation. Numerical experiments find that our method is superior to traditional interpolation methods in accuracy, especially for large upsampling ratios. Its relative error is less than 2% even for a 40-time upsampling;in contrast, the relative error of linear and cubic interpolation is up to 90% and 41% in the same situation, respectively. We further verify the feasibility of our method for 3D heterogeneous models with rough topography, multilayer heterogeneity, and random perturbations of background models. The proposed method yields a significant speeding of the multiscale seismic simulation using the FEM for 3D models with complex local structures and topographies while being highly accurate.

关键词： boundary extrapolation domain reduction method finite-element method Fourier interpolation seismic wave simulation

来源：评论

学校读者我要写书评

暂无评论

A Novel method for Stability Analysis of Weakly Inclined Subgrade by Centrifuge Model Test and the finite-element method

引用

INTERNATIONAL JOURNAL OF GEOMECHANICS 2022年第4期22卷

作者： Sheng, Ke Liu, Xin Shan, Hao Qian, Xiaoxu Wang, Guisen Hong, Baoning Hohai Univ Coll Civil & Transportat Engn Nanjing 210098 Peoples R China Xuzhou Univ Technol Sch Civil Engn Xuzhou 221018 Jiangsu Peoples R China

The stability analysis of a weakly inclined subgrade is a crucial topic of geotechnical engineering. This work established a novel method based on the Swedish method to solve the stability analysis of a weakly inclined subgrade. Centrifuge model tests were used to examine the failure mechanisms of a weakly inclined subgrade. Then, a series of two-dimensional (2D) and three-dimensional (3D) numerical simulations analyses were performed to find the influencing factor affecting the weakly inclined subgrade's stability. According to the experimental and numerical simulation results, there were obvious differences in the instability failure mode between the weakly inclined and the weakly horizontal subgrades. In the novel method, the mechanism that caused the instability of the weakly inclined subgrade was studied by introducing influential force and additional force. While the influential force suggested the impact of the potential difference, the additional force indicated the gravity impact emanating from the lateral embankment. After contrasting the results in the engineering example, the proposed method's viability was confirmed. The proposed method was found more suitable for performing the stability analysis of a weakly inclined subgrade than the traditional slice methods.

关键词： Weakly inclined subgrade Stability analysis Centrifuge model test finite-element method Modified Swedish method

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：