检索结果-内蒙古大学图书馆

Analytical investigations of in situ stress inversion from borehole breakout geometries

Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2375-2387页

作者： Zizhuo Xiang Taehyun Moon Joung Oh Guangyao Si Ismet Canbulat School of Minerals and Energy Resources Engineering University of New South WalesSydneyNSW2052Australia HNTB Corporation 3505th Ave.58th FloorNew YorkNY10118USA

This study aims to investigate the feasibility of deriving in situ horizontal stresses from the breakout width and depth using the analytical ***-three breakout data with different borehole sizes were collected and three failure criteria were *** on the Kirsch equations,relatively accurate major horizontal stress(sH)estimations from known minor horizontal stress(sh)were achieved with percentage errors ranging from 0.33%to 44.08%using the breakout *** Mogi-Coulomb failure criterion(average error:13.1%)outperformed modified Wiebols-Cook(average error:19.09%)and modified Lade(average error:18.09%)failure ***,none of the tested constitutive models could yield reasonable sh predictions from known sH using the same approach due to the analytical expression of the redistributed stress and the nature of the constitutive *** consideration of this issue,the horizontal stress ratio(sH/sh)is suggested as an alternative input,which could estimate both sH and sh with the same level of ***,the estimation accuracies for both large-scale and laboratory-scale breakouts are comparable,suggesting the applicability of this approach across different breakout *** breakout depth,conformal mapping and complex variable method were used to calculate the stress concentration around the breakout tip,allowing the expression of redistributed stresses using binomials composed of sH and ***,analysis of the breakout depth stabilisation mechanism indicates that additional parameters are required to utilise normalised breakout depth for stress estimation compared to breakout *** parameters are challenging to obtain,especially under field conditions,meaning utilising normalised breakout depth analytically in practical applications faces significant challenges and remains infeasible at this ***,the normalised breakout depth should still be considered a critical input for any empirical and statistical stres

关键词： Borehole failure In situ stress estimation In situ horizontal stress ratio Conformal mapping complex variable method Breakout stabilisation

来源：评论

学校读者我要写书评

暂无评论

Non-iterative stress-displacement solution for surrounding rock mass with multiple non-circular deep tunnels

引用

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL methodS IN GEOMECHANICS 2024年第13期48卷 3261-3283页

作者： Ye, Zi Kun Ai, Zhi Yong Tongji Univ Dept Geotech Engn Key Lab Geotech & Underground Engn Minist Educ State Key Lab Disaster Reduct Civil Engn 1239 Siping Rd Shanghai 200092 Peoples R China

A non-iterative stress-displacement solution is proposed in this paper to investigate surrounding rock mass with multiple non-circular deep tunnels. Compared with the Schwarz alternating method, the proposed method only spends one-time matrix operation, showing considerable efficiency and accuracy of the matrix solution. First, a matrix solution is formulated to obtain the conformal mapping function for the non-circular tunnel. Then, in consideration of multiple boundary conditions, the generalized complex variable theory and fast Fourier transform (FFT) algorithm are used to formulate a matrix solution of potential functions. The stress and displacement fields around multiple non-circular tunnels can be further determined from the matrix solution. A series of numerical examples are conducted to verify the proposed method, perform the convergency study, and discuss the effects of tunnel geometries, distances, and arrangements. The convergency study shows that the more accurate conformal mapping function requires more sampling points in the FFT. In addition, the high stress zone would be amplified if the arrangement of multiple tunnels makes the high stress zone adjacent or overlapped.

关键词： complex variable method Fourier series fitting multiple non-circular tunnels non-iterative stress-displacement solution

来源：评论

学校读者我要写书评

暂无评论

Effect of hydrogen embrittlement on dislocation emission from a semi-elliptical surface crack tip in nanometallic materials

引用

ARCHIVE OF APPLIED MECHANICS 2024年第11期94卷 3377-3388页

作者： Song, Xiaoya Liu, Wei Jiang, Fujun Yu, Min Peng, Xianghua Cent South Univ Forestry & Technol Hunan Prov Key Lab Engn Rheol Changsha 410004 Peoples R China Hunan Womens Univ Coll Informat Sci & Engn Changsha 410004 Peoples R China

A theoretical model was established to investigate the interaction between hydrogen clusters and edge dislocations emitted from a semi-elliptical surface crack tip in deformed nanometallic materials. The model's solution was obtained by using the complex method, and the influence of the concentration and location of hydrogen clusters, temperature, crack shape, material constants, and the dislocation emission angle on the critical stress intensity factor (SIFs) corresponding to the first dislocation emission from crack tips was investigated through numerical analysis. The results show that dislocations are easily emitted from the crack tip at high hydrogen concentration, and hydrogen clusters close to the crack tip will hinder the emission of dislocations from its crack tip. When considering the influence of hydrogen cluster, an increase in temperature, an extension of crack length or an increase in crack tip curvature radius can all make the emission of dislocations at the crack tip difficult, thereby reducing the toughness of the material caused by dislocation emission.

关键词： Hydrogen embrittlement complex variable method Dislocation emission Stress intensity factor Surface cracks

来源：评论

学校读者我要写书评

暂无评论

Uniformity of anti-plane stresses inside a nonlinear elastic elliptical or parabolic inhomogeneity

引用

MATHEMATICS AND MECHANICS OF SOLIDS 2024年第1期29卷 121-128页

作者： Wang, Xu Schiavone, Peter East China Univ Sci & Technol Sch Mech & Power Engn Shanghai Peoples R China Univ Alberta Dept Mech Engn Edmonton AB Canada East China Univ Sci & Technol Sch Mech & Power Engn 130 Meilong Rd Shanghai 200237 Peoples R China Univ Alberta Dept Mech Engn 10-203 Donadeo Innovat Ctr Engn Edmonton AB T6G 1H9 Canada

We study the anti-plane strain problem associated with a p-Laplacian nonlinear elastic elliptical inhomogeneity embedded in an infinite linear elastic matrix subjected to uniform remote anti-plane stresses. A full-field exact solution is derived using complex variable techniques. It is proved that the stress field inside the elliptical inhomogeneity is nevertheless uniform. The uniformity of stresses is also observed inside a p-Laplacian nonlinear elastic parabolic inhomogeneity.

关键词： Nonlinear elasticity p-Laplacian elliptical inhomogeneity parabolic inhomogeneity uniform stress anti-plane elasticity complex variable method

来源：评论

学校读者我要写书评

暂无评论

Mechanical behaviours of existing tunnels due to multiple-tunnel excavations considering construction sequence

引用

TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 2024年 152卷

作者： Liu, Xiang Fang, Huangcheng Jiang, Annan Zhang, Dingli Fang, Qian Lu, Tong Bai, Jinrui Dalian Maritime Univ Liaoning Key Lab Marine Environm Bridge & Tunnel Dalian 116026 Peoples R China Beijing Jiaotong Univ Key Lab Urban Underground Engn Educ Minist Beijing 100044 Peoples R China

An analytical method utilizing the extended complex variable approach is presented to investigate the mechanical characteristics of pre-existing tunnels affected by the excavation of multiple tunnels. In contrast to conventional methods, this proposed approach accommodates the consideration of the construction sequence of the newly introduced multiple tunnels, the cross-sectional shapes of new tunnels, as well as different displacement and stress boundary conditions at the inner boundary. The validity of the proposed method is confirmed through numerical simulations and subsequent comparisons with other established methods. Subsequently, an in-depth analysis is performed on a project involving four shield tunnels constructed beneath existing tunnels in Shen Zhen. This analysis explores the effects of the construction sequence, the cross-sectional design of new tunnels, stress release coefficients, and deformation convergence patterns on the mechanical response of the preexisting tunnel. Additional influencing factors, such as the horizontal clearance between new tunnels and the supporting stiffness of concrete liners, are also thoroughly analysed. The results demonstrate that our proposed method exhibits exceptional applicability and universality in predicting the mechanical behaviour of existing tunnels affected by new tunnel construction.

关键词： Existing tunnel Multiple -tunnel excavation Construction sequence Analytical solutions complex variable method

来源：评论

学校读者我要写书评

暂无评论

A semi-analytical method for frictional contact analysis between rock mass and concrete linings

引用

APPLIED MATHEMATICAL MODELLING 2022年 105卷 17-28页

作者： Fang, Huangcheng Zhang, Dingli Fang, Qian Beijing Jiaotong Univ Key Lab Urban Underground Engn Educ Minist Beijing 100044 Peoples R China

The rock-lining interface typically exhibits a complex frictional contact behavior. Thus far, there has been no analytic method to analyze the frictional contact problems of arbitraryshaped tunnels with concrete linings. In this work, we propose a novel analytic method to perform the frictional contact analysis of multiple lined tunnels based on the generalized complex variable method. Using two special composite analytic functions, the mechanical field in a multiply-connected domain can be accurately expressed, and the solution to the contact problem can thus be obtained in a closed mathematical form. In the present theoretical framework, the general contact condition is considered, where the contact mode is described using two complementary functions. The basic linear equations are obtained by satisfying the stress and contact boundary conditions at a finite number of discrete points. Since the contact analysis is a highly nonlinear problem, we propose an iterative scheme to determine the contact states at different positions on the rock-lining interface. Finally, a verification example and parametric investigation are performed to demonstrate the effectiveness and practicability of the proposed method. (c) 2021 Elsevier Inc. All rights reserved.

关键词： complex variable method Frictional contact Concrete lining Multiple tunnels Rock mass complex variable method Frictional contact Concrete lining Multiple tunnels Rock mass

来源：评论

学校读者我要写书评

暂无评论

A compressible liquid inclusion of arbitrary shape in an isotropic elastic matrix

引用

MATHEMATICS AND MECHANICS OF SOLIDS 2025年

作者： Jouneghani, Romina Ardeshiri Wang, Xu Schiavone, Peter Univ Alberta Dept Mech Engn 10-203 Donadeo Innovat Ctr Engn Edmonton AB T6G 1H9 Canada East China Univ Sci & Technol Sch Mech & Power Engn 130 Meilong Rd Shanghai 200237 Peoples R China

We use Muskhelishvili's complex variable formulation to solve the plane-strain problem of a compressible liquid inclusion of arbitrary shape embedded within an infinite isotropic elastic matrix under uniform remote in-plane stresses. First, the exterior of the domain occupied by the liquid inclusion is mapped onto the exterior of a unit circle in the image plane using a mapping function that contains an arbitrary number of terms. With the aid of a modified form of analytic continuation, a set of linear algebraic equations with relatively simple structure is obtained. Once this set of linear algebraic equations is solved, the internal uniform hydrostatic stress field within the liquid inclusion and the elastic field in the matrix (characterized by a pair of analytic functions) are fully determined. We illustrate our theory by deriving a closed-form solution for a hypotrochoidal liquid inclusion and comparing our results with those available in the existing literature. In addition, numerical results for the internal uniform hydrostatic stress within liquid inclusions with an n-fold axis of symmetry are presented graphically to examine the influence of the number of terms used in the mapping function. Finally, we determine the internal hydrostatic stress for the case of a rectangular liquid inclusion with various aspect ratios.

关键词： Compressible liquid inclusion arbitrary shape complex variable method conformal mapping analytic continuation internal hydrostatic stress

来源：评论

学校读者我要写书评

暂无评论

Analyzing time-dependent rock-concrete interaction: A solution for non-circular tunnels

引用

APPLIED MATHEMATICAL MODELLING 2025年 145卷

作者： Sayari, Amir Alam Kargar, Ali Reza Khosravi, Mohammad Hossein Pipatpongsa, Thirapong Univ Tehran Coll Engn Sch Min Engn Tehran Iran Univ Birjand Fac Engn Dept Min Engn Birjand Iran Natl Yang Ming Chiao Tung Univ Dept Civil Engn Hsinchu Taiwan

Many researchers have explored the complex time-dependent behavior of rock-concrete interaction in lined tunnels. However, for non-circular tunnel configurations, no analytical solution has been proposed yet. The presence of varying curvature along tunnel boundaries in non-circular tunnels leads to diverse effects on stress and strain components in both the lining and surrounding mass over time. As time progresses, the accuracy of stress and strain assessment significantly decreases, especially at boundaries with high curvature, even when fine grid mesh sizes are used in numerical models. To address these challenges, a novel time-dependent analytical solution in plane strain is introduced for evaluating induced stress and strain fields around a lined noncircular tunnel subjected to non-hydrostatic in situ stress. The solution, developed using the complex variable method by Muskhelishvili and conformal mapping functions, results in a system of first-order linear differential equations. This approach was validated using COMSOL finite element software, demonstrating a substantial reduction in stress evaluation errors and time consumed compared to the software. Finally, a sensitivity analysis on Burgers model parameters performed, which revealed different effects on stress induced around tunnels in short and longterm. Notably, this solution is applicable to tunnels of any shape and compatible with various linear viscoelastic constitutive models for rock masses.

关键词： Lined non-circular tunnels Plane strain condition complex variable method Conformal mapping Time-dependent solution Viscoelastic constitutive model

来源：评论

学校读者我要写书评

暂无评论

The intrinsic relationship of the thermal stress intensity factor and the temperature difference at the crack surface

引用

JOURNAL OF THERMAL STRESSES 2024年第7期47卷 897-908页

作者： Zhang, Qianqian Song, Haopeng Gao, Cun-Fa Nanjing Univ Aeronaut & Astronaut State Key Lab Mech & Control Mech Struct Nanjing Peoples R China

The intrinsic relationship of the thermal stress intensity factor and temperature difference between the upper and lower surface of the crack have been studied in this paper. The results show the thermal stress intensity factor is always proportional to the temperature difference between the upper and lower crack surface, and the ratio depends only on material parameters and crack length, but is independent of loading condition. For a finite medium problem, the above conclusion is still valid by simply adding a size related correction factor. When the size of medium is 10 times larger than the crack size, the size related correction factor is less than 1.019, that is, the error is less than 2%. Our conclusion provides a theoretical basis to estimate the localization thermal stress intensity factor simply by measuring the temperature difference of the crack surface.

关键词： complex variable method temperature difference thermal loading the thermal stress intensity factor

来源：评论

学校读者我要写书评

暂无评论

Stress analysis for a lip-shaped crack in a thermoelectric plate under combined electrical and thermal loadings

引用

ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK 2024年第1期75卷 19-19页

作者： Yu, Chuanbin Du, Chaofan Xing, Shichao Gao, Cun-Fa Yangzhou Univ Coll Architectural Sci & Engn Yangzhou 225127 Jiangsu Peoples R China Tongling Univ Anhui Higher Educ Inst Key Lab Construct Hydraul Robots Tongling 244000 Anhui Peoples R China Tongling Univ Key Lab Addit Mfg Tongling City Tongling 244000 Anhui Peoples R China Nanjing Univ Aeronaut & Astronaut State Key Lab Mech & Control Aerosp Struct Nanjing 210016 Peoples R China

This study focuses on analyzing a slanted lip-shaped crack within a thermoelectric plate that experiences both a temperature gradient and an electric potential gradient. Based on the electrically insulated and thermally permeable crack model, we derive analytical solutions for the thermoelectric field and the associated thermal stress field in the cracked thermoelectric material by employing the complex variable method. Subsequently, we evaluate the stress intensity factors at the tips of the lip-shaped crack. Under the impact of thermoelectric loading, both mode-I and mode-II stress intensity factors occur at the tips of a slanted lip-shaped crack. Numerical examples are provided to demonstrate the influence of crack width, crack angle and thermal conductivity of the filling medium on the stress intensity factors at the crack tip.

关键词： Thermoelectric material Lip-shaped crack complex variable method Stress intensity factors

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：