检索结果-内蒙古大学图书馆

Characterization of fatigue crack growth rate by digital image correlation measurements of the plastic zone considering multiple parameters

引用

ENGINEERING FRACTURE MECHANICS 2025年 315卷

作者： Zhao, Xun Li, Jian Sun, Tao Deng, Han Zhu, Jian-Guo Tang, Ming-Yang Li, Yi-Kun Jiangsu Univ Inst Struct Hlth Monitoring Fac Civil Engn & Mech Zhenjiang 212013 Peoples R China

The development of digital image correlation (DIC) has led to a growing interest in the use of DIC methods for crack tip plastic zone size assessment and non-linear parametric characterization of fatigue crack growth rate (FCGR). This paper presents a study of the stress and strain evolution at the crack tip, employing the use of DIC to monitor the plastic deformation at the crack tip during fatigue crack growth (FCG) under varying load ratios. Furthermore, the dimensions of the plastic zone at varying crack lengths are quantified by combining DIC with theoretical methods. A methodology for forecasting the FCGR is presented, based on the measured dimensions of the plastic zone. In comparison with preceding methodologies, the proposed approach incorporates the effects of load ratio and fracture toughness, and characterizes FCGR by normalizing the equivalent plastic zone size through the analysis of the contribution of multiple parameters to the distinct phases of FCG. And ultimately obtains a FCGR prediction model with a correlation coefficient R 2CORR of 0.966, demonstrates a superior fit to the FCGR in comparison to the stress intensity factor. Finally, the fracture morphology evolution of TC4ELI alloys under different loading conditions was analyzed by electron microscopy, and the results showed that the observations of fracture morphology at different loading ratios and FCG stages were consistent with the macroscopic results of monotonic cyclic plastic deformation analyzed by DIC.

关键词： Digital image correlation Plastic zone size Load ratio Fatigue crack growth multiple parameters

来源：评论

学校读者我要写书评

暂无评论

New Existence Result of Positive Solutions for a Class of Fractional Kirchhoff-Type Systems with multiple parameters

引用

RUSSIAN MATHEMATICS 2025年第1期69卷 11-22页

作者： Guefaifia, R. Bouali, T. Rasouli, S. H. Qassim Univ Buraydah 51452 Saudi Arabia Echahid Cheikh Larbi Tebessi Univ Tebessa 12002 Algeria Babol Noshirvani Univ Technol Babol Iran

This paper is devoted to the existence of positive weak solutions for a class of fractional Kirchhoff-type systems with multiple parameters. By using the sub-supersolution method and some analysis techniques, we prove a new existence result. To the best of our knowledge, our results are new in the study of fractional Kirchhoff-type systems.

关键词： fractional Kirchhoff-type systems positive solutions sub-supersolution multiple parameters

来源：评论

学校读者我要写书评

暂无评论

multiple parameters Optical Sensing Using Fiber Ring Laser Based on Fiber Bragg Gratings and 1064 nm Semiconductor Optical Amplifier

引用

OPTICS AND SPECTROSCOPY 2019年第6期127卷 1057-1061页

作者： Liaw, Shien-Kuei Li, Dong-Chang Lee, Hsin-Che Huang, Yi-Zhi Shin, Chow-Shing Lee, Yin-Wen Natl Taiwan Univ Sci & Technol Dept Elect & Comp Engn Taipei 10607 Taiwan Natl Taiwan Univ Dept Mech Engn Taipei 10617 Taiwan Natl Taipei Univ Technol Dept Electroopt Engn Taipei 10608 Taiwan

In this paper, a semiconductor optical amplifier (SOA) based 1064 nm fiber ring laser with 63.56 dB optical signal-to-noise ratio (OSNR) is demonstrated. The stable performance is measured for six hours with lasing peak variation of <=+/- 0.115 dB and wavelength variation of <=+/- 0.006 nm. Combining the fiber ring laser with fiber Bragg gratings (FBGs), the SOA based fiber ring laser is applied to sense stretch, squeeze, and temperature variation. The results show high linearity, which is suitable for interpolation method prediction and evaluation. A large dynamic range of up to 10 km is also demonstrated for remote sensing applications.

关键词： optical amplifier fiber ring laser fiber Bragg gratings semiconductor optical amplifier multiple parameters

来源：评论

学校读者我要写书评

暂无评论

Numerical Study of the Influence of multiple parameters on Hang-ups: Insight From a Structural and Mechanical Characteristics Analysis

引用

ROCK MECHANICS AND ROCK ENGINEERING 2024年第5期57卷 4073-4087页

作者： Sun, Hao Zhao, Lishan Wei, Lichang Jia, Junze Zhou, Shenggui Univ Sci & Technol Beijing Dept Resources Engn Key Lab Minist Educ Efficient Min & Safety Met Min 30 Xue Yuan Lu Coll Rd Beijing 100083 Peoples R China Univ Sci & Technol Beijing Sch Civil & Resource Engn Beijing 100083 Peoples R China Zijin Min Grp Co Ltd Shanghang 364200 Fujian Peoples R China

To understand the hang-up characteristics of caved ore and rock in caving mining under different macro factors, and to provide better guidance for drawpoint layout design and hang-up frequency prediction, numerical tests were conducted on an isolated draw model to investigate the influence of particle size, friction property, and overburden stress based on a rolling resistance model. A 3D phase diagram of hang-ups was obtained. Furthermore, the structural and mechanical characteristics of the local packing system of caved ore and rock under different hang-up and flow states were analyzed using statistical mechanics. The findings indicate that: (1) The proportion of hang-up events which is influenced by several factors decreases as the ratio of drawpoint size to average particle size increases, but increases with higher particle friction coefficient and overburden stress. And the ratio of drawpoint size to average particle size has the most significant impact on proportion of hang-up events, followed by particle friction coefficient, while overburden stress has the least impact. (2) The ratio of drawpoint size to average particle size primarily affects hang-ups by influencing average force chain strength, the particle friction coefficient mainly affects hang-ups through its influence on collimation coefficient of force chain and void ratio, and the overburden stress primarily affects hang-ups through its influence on the average force chain strength and the number of force chains. The average force chain strength and number of force chains in the local packing system of caved ore and rock serve as crucial meso-mechanical parameters that affect hang-ups. A 3D phase diagram of hang-ups was *** particle size most affects hang-up frequency, followed by particle friction coefficient and finally overburden *** strength and number of force chains serve as crucial meso-mechanical parameters that affect hang-ups.

关键词： Block caving Hang-ups multiple parameters Structural and mechanical characteristics PFC modelling

来源：评论

学校读者我要写书评

暂无评论

Reduced-order modeling of time-dependent PDEs with multiple parameters in the boundary data

引用

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING 2007年第4-6期196卷 1030-1047页

作者： Gunzburger, Max D. Peterson, Janet S. Shadid, John N. Florida State Univ Sch Computat Sci Tallahassee FL 32306 USA Sandia Natl Labs Computat Sci Dept Albuquerque NM 87185 USA

The computational approximation of solutions to nonlinear partial differential equations (PDEs) such as the Navier-Stokes equations is often a formidable task. For this reason, there is significant interest in the development of very low-dimensional models that can be used to determine reasonably accurate approximations in simulation and control problems for PDEs. Many concrete tests have been reported on in the literature that show that several classes of reduced-order models (ROMs) are effective, i.e., an accurate approximate solution can be obtained using very low-dimensional ROMs. Most of these tests involved problems for which the solution depends on only a single parameter appearing in the boundary data. The extension of the techniques used in those tests to the case of multiple parameters is not a straightforward matter. Here, we present, test, and compare two methods for treating, within the context of a class of ROMs, inhomogeneous Dirichlet-type boundary conditions that contain multiple parameters. In this study, we focus on the proper orthogonal decomposition (POD) approach to ROM;however, the issues and results discussed here in the POD context apply equally well to other ROM approaches. (c) 2006 Elsevier B.V. All rights reserved.

关键词： reduced-order modeling multiple parameters nonlinear partial differential equations

来源：评论

学校读者我要写书评

暂无评论

STATISTICAL INFERENCE OF SEMIDEFINITE PROGRAMMING WITH multiple parameters

引用

JOURNAL OF INDUSTRIAL AND MANAGEMENT OPTIMIZATION 2020年第3期16卷 1527-1538页

作者： Wang, Jiani Zhang, Liwei Dalian Univ Technol Sch Math Sci Dalian 116024 Peoples R China

The parameters in the semidefinite programming problems generated by the average of a sample, may lead to the deviation of the optimal value and optimal solutions due to the uncertainty of the data. The statistical properties of estimates of the optimal value and the optimal solutions are given in this paper, when the estimated parameters are both in the objective function and in the constraints. This analysis is mainly based on the theory of the linear programming and the perturbation theory of the semidefinite programming.

关键词： Linear semidefinite programming multiple parameters linear operator theory constraint nondegeneracy statistical inference asymptotics

来源：评论

学校读者我要写书评

暂无评论

Comprehensive Influence Analysis of multiple parameters on the Safety Thickness against Water Inrush in Shield Tunnel

引用

INTERNATIONAL JOURNAL OF GEOMECHANICS 2020年第12期20卷

作者： Li, Li-ping Xiong, Yi-fan Wang, Jing Gao, Xue-chi Wang, Kai Sun, Hao-cheng Fang, Zhong-dong Shandong Univ Geotech & Struct Engn Res Ctr Jinan 250061 Shandong Peoples R China Shandong Univ Sch Qilu Transportat Jinan 250002 Shandong Peoples R China Qilu Transportat Dev Grp Co Ltd Jinan 250101 Shandong Peoples R China

This paper focuses on the construction of urban rail transit projects to prevent the risk of water inrush disasters faced during subway construction in cities with abundant groundwater and well-developed karst landforms. In view of the reserved safety thickness for the tunnel face with an anterosuperior karst cave filled with water in urban subway construction, the authors study the influence law and response sensitivity of different types and diameters of the shield machine cutter head and different diameters and water pressure of the anterosuperior karst cave filled with water on the safety thickness. The authors relied on the actual working conditions of the Wangfuzhuang station to the Dayangzhuang station section of the Jinan Metro Line R1 phase I project for this study used the fluid-structure coupling method of COMSOL Multiphysics 5.3 software to simulate the process of shield tunneling and the time of water inrush, and combined the three-dimensional finite-element numerical simulation results and multiple linear regression method to deduce the formula of the reserved safety thickness for the tunnel face with an anterosuperior karst cave filled with water. The conclusions can be used to guide shield excavation in karst areas of urban subways.

关键词： Water inrush disaster Reserved safety thickness Shield tunnel Karst cave multiple parameters

来源：评论

学校读者我要写书评

暂无评论

Positive solutions for a class of p-Laplacian systems with multiple parameters

引用

JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS 2007年第2期335卷 1013-1019页

作者： Ali, Jaffar Shivaji, R. Mississippi State Univ Dept Math Mississippi State MS 39759 USA

Consider the system -Delta(p)u=;lambda(1)f(v)+mu(1)-h(u) in Omega, -Delta(q)v= -lambda(2)g(u)+mu 2 gamma(v) in Omega, u=0=v on partial derivative Omega, where Delta(s)z = div(vertical bar del z vertical bar(s-2)del z), s > 1, lambda(1),lambda(2), mu(1) and mu(2) are nonnegative parameters, and Omega is a bounded domain in R-N with smooth boundary partial derivative Omega. We prove the existence of a large positive solution for lambda(1) + mu (1) and lambda(2) + mu(2) large when for every M > 0, lim x ->infinity h(x)/x(p-1) =0 and lim x ->infinity gamma(x)/x(q-1) =0. In particular, we do not assume any sign conditions on f (0), g (0), h (0) or gamma (0). We also discuss a multiplicity results when f (0) = g (0) = h (0) gamma(0) = 0. (c) 2007 Elsevier 1nc. All rights reserved.

关键词： positive solutions p-Laplacian systems multiple parameters

来源：评论

学校读者我要写书评

暂无评论

Fractional Laplacian Elliptic Systems with multiple parameters

引用

COMPLEX ANALYSIS AND OPERATOR THEORY 2024年第7期18卷 1-11页

作者： Sousa, J. Vanterler da C. Bouali, Tahar Guefaifia, Rafik Univ Estadual Maranhao Dept Math Aerosp Engn DEMATIPPGEA BR-65054 Sao Luis MA Brazil Echahid Cheikh Larbi Tebessi Univ Tebessa Dept Math Tebessa Algeria Echahid Cheikh Larbi Tebessi Univ Tebessa Lab Math Informat & Syst LAMIS Tebessa Algeria Qassim Univ Coll Sci Dept Math Buraydah 51452 Saudi Arabia

In this paper, we concern the study of the existence of positive weak solutions for a class of fractional Laplacian systems with multiple parameters. Some new conditions to that the existence of a positive solution for the considered system is established by using the method of sub-super solutions which extends and complements previously known results in the literature.

关键词： Fractional Laplacian systems Positive solutions Sub-supersolution multiple parameters Nonlinear equations

来源：评论

学校读者我要写书评

暂无评论

Quantitative assessment of right ventricular size and function with multiple parameters from artificial intelligence-based three-dimensional echocardiography: A comparative study with cardiac magnetic resonance

引用

ECHOCARDIOGRAPHY-A JOURNAL OF CARDIOVASCULAR ULTRASOUND AND ALLIED TECHNIQUES 2022年第2期39卷 223-232页

作者： Zhu, Ying Bao, Yuwei Zheng, Kangchao Zhou, Wei Zhang, Jun Sun, Ruiying Deng, Youbin Xia, Liming Liu, Yani Huazhong Univ Sci & Technol Tongji Hosp Tongji Med Coll Dept Med Ultrasound 1095 Jiefang Rd Wuhan 430030 Peoples R China Huazhong Univ Sci & Technol Tongji Hosp Tongji Med Coll Dept Radiol Wuhan Peoples R China

Aims This study aimed to explore the validation and the diagnostic value of multiple right ventricle (RV) volumes and functional parameters derived from a novel artificial intelligence (AI)-based three-dimensional echocardiography (3DE) algorithm compared to cardiac magnetic resonance (CMR). Methods and results A total of 51 patients with a broad spectrum of clinical diagnoses were finally included in this study. AI-based RV 3DE was performed in a single-beat HeartModel mode within 24 hours after CMR. In the entire population, RV volumes and right ventricular ejection fraction (RVEF) measured by AI-based 3DE showed statistically significant correlations with the corresponding CMR analysis (p < 0.05 for all). However, the Bland-Altman plots indicated that these parameters were slightly underestimated by AI-based 3DE. Based on CMR derived RVEF < 45% as RV dysfunction, end-systolic volume (ESV), end-systolic volume index (ESVi), stroke volume (SV), and RVEF showed great diagnostic performance in identifying RV dysfunction, as well as some non-volumetric parameters, including tricuspid annular systolic excursion (TAPSE), fractional area change (FAC), and free-wall longitudinal strains (LS) (p < 0.05 for all). The cutoff value was 43% for RVEF with a sensitivity of 94% and specificity of 67%. Conclusion AI-based 3DE could provide rapid and accurate quantitation of the RV volumes and function with multiple parameters. Both volumetric and non-volumetric measurements derived from AI-based 3DE contributed to the identification of the RV dysfunction.

关键词： artificial intelligence multiple parameters right ventricle three-dimensional echocardiography

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：