Journal of Mechanics最新文献_第5页

Effects of Material Characteristics on Thermal Stress around an Equiangular Polygonal Hole in a Thermoelectric Material 材料特性对热电材料等角多边形孔周围热应力的影响

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2023-03-24 DOI: 10.1093/jom/ufad003

M. Shen, Yi-Lun Liao, S. Tseng, C. Chao

{"title":"Effects of Material Characteristics on Thermal Stress around an Equiangular Polygonal Hole in a Thermoelectric Material","authors":"M. Shen, Yi-Lun Liao, S. Tseng, C. Chao","doi":"10.1093/jom/ufad003","DOIUrl":"https://doi.org/10.1093/jom/ufad003","url":null,"abstract":"\u0000 In this study, we conducted a theoretical analysis of thermal stress around an arbitrarily-shaped hole in a thermoelectric material under electric current density and energy flux loading. Based on complex variable methods, conformal mapping, and analytical continuation theorem, the exact solutions of the thermal stress around a hole were obtained for the Seebeck coefficient and electric and heat conductivity. Based on the conversion efficiency equation of thermoelectric materials, higher electrical conductivity, and lower heat conductivity should be selected to achieve an optimal design. The theoretical results indicated that higher electrical conductivity could reduce the thermal stress around the hole. However, energy flux and thermal stress concentration might be generated around the adiabatic hole due to the presence of a matrix with lower heat conductivity. Hence, thermoelectric materials with lower thermal conductivity should be selected carefully to avoid premature failure around the hole caused by thermal stress concentration. Finally, we also obtained and discussed the stress intensity factors of a hypocycloid-type crack.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43595010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A direct numerical simulation method for solid-solid collision and coupling with fluid 固体-固体碰撞与流体耦合的直接数值模拟方法

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2023-03-03 DOI: 10.1093/jom/ufad001

Ming Yang, Ju-bao Liu, Y. Ding, Q. Yue, Qiang Zhang

引用次数: 0

Computational Aerodynamics With Isogeometric Analysis 计算空气动力学与等几何分析

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2023-02-17 DOI: 10.1093/jom/ufad002

Y. Bazilevs, K. Takizawa, T. Tezduyar, A. Korobenko, T. Kuraishi, Yuto Otoguro

{"title":"Computational Aerodynamics With Isogeometric Analysis","authors":"Y. Bazilevs, K. Takizawa, T. Tezduyar, A. Korobenko, T. Kuraishi, Yuto Otoguro","doi":"10.1093/jom/ufad002","DOIUrl":"https://doi.org/10.1093/jom/ufad002","url":null,"abstract":"\u0000 The superior accuracy isogeometric analysis (IGA) brought to computations in fluid and solid mechanics has been yielding higher fidelity in computational aerodynamics. The increased accuracy we achieve with the IGA is in the flow solution, in representing the problem geometry, and, when we use the IGA basis functions also in time in a space–time (ST) framework, in representing the motion of solid surfaces. It is of course as part of a set of methods that the IGA has been very effective in computational aerodynamics, including complex-geometry aerodynamics. The set of methods we have been using can be categorized into those that serve as a core method, those that increase the accuracy, and those that widen the application range. The core methods are the residual-based variational multiscale (VMS), ST-VMS, and arbitrary Lagrangian–Eulerian VMS methods. The IGA and ST-IGA are examples of the methods that increase the accuracy. The complex-geometry IGA mesh generation method is an example of the methods that widen the application range. The ST Topology Change method is another example of that. We provide an overview of these methods for IGA-based computational aerodynamics and present examples of the computations performed. In computational flow analysis with moving solid surfaces and contact between the solid surfaces, it is a challenge to represent the boundary layers with an accuracy attributed to moving-mesh methods and represent the contact without leaving a mesh protection gap.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42833550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Influence on structure and fracture mechanics evaluations of a BWR feedwater nozzle following weld overlay repair 堆焊修复对沸水堆给水喷嘴结构及断裂力学评价的影响

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2023-01-01 DOI: 10.1093/jom/ufad008

Ru-Feng Liu, Ming-Chung Young

{"title":"Influence on structure and fracture mechanics evaluations of a BWR feedwater nozzle following weld overlay repair","authors":"Ru-Feng Liu, Ming-Chung Young","doi":"10.1093/jom/ufad008","DOIUrl":"https://doi.org/10.1093/jom/ufad008","url":null,"abstract":"This present paper summarizes applying weld overlay repair on the feedwater nozzle in a boiling water reactor, and evaluates the influence on the structure and fracture mechanics of the component. The requirements for utilizing a full structural weld overlay, including the weld overlay design, effects of welding residual stresses (WRSs), impacts of weld shrinkage, prediction of potential flaw growth, and influence on ASME Code Section III design evaluations, are further defined in ASME Code Case N-504–2. In order to confirm the effectiveness of the weld overlay design of the nozzle, the WRSs following overlay installation were determined using engineering simulation software. The impacts of weld shrinkage from overlay welding are also addressed. The shrinkage stresses were evaluated via a numerical model of the attached piping system to ensure the design margins of the pipe structure. Since the weld overlay technique is well known to be effective in mitigating crack initiation or cracking to leakage, a fatigue crack growth prediction under ASME Code Section XI must be conducted to address the fatigue qualification of the affected component. The ASME Code Section III construction qualification of the whole nozzle region must consider the applicable thermal transient stresses, structural discontinuities, and bimetallic effects that are caused by the weld overlay. This investigation proves that the current stress analyses of the nozzle and the pipe structure are not significantly affected by the added overlay mass, so the structural integrity of the component can be ensured, meeting the requirements of ASME Code Case N-504–2.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61542385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation of unconfined seepage in soil–rock mixture slope by virtual element method 用虚元法模拟土石混合体边坡无侧限渗流

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2023-01-01 DOI: 10.1093/jom/ufad011

Yinghao Sun, Qi Yi, Jiao Wang, Guanhua Sun, Shan Lin

引用次数: 0

Preface Recent advances in isogeometric analysis 等几何分析的新进展

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2023-01-01 DOI: 10.1093/jom/ufac051

引用次数: 0

Pressure-sensitive paint measurements on the cavity with passive control devices under transonic flow 用无源控制装置对跨声速流腔进行压敏涂料测量

4区工程技术

Journal of Mechanics Pub Date : 2023-01-01 DOI: 10.1093/jom/ufad023

Jun-Kai Ouyang, Yi-Ting Liao, Yen-Ting Hsu, Cheng-Chi Lee, Yu-Hung Lin, Chung-Lung Chen, Wei-Hsiang Wang

引用次数: 0

A numerical investigation of microtube length effect on convective boiling 微管长度对对流沸腾影响的数值研究

4区工程技术

Journal of Mechanics Pub Date : 2023-01-01 DOI: 10.1093/jom/ufad029

Hua-Yi Hsu, Yu-Chen Lin, Zong-You Chen, Ying Wang, Cheng-En Li, Shong-Han Pai, Chia-Wei Lin

{"title":"A numerical investigation of microtube length effect on convective boiling","authors":"Hua-Yi Hsu, Yu-Chen Lin, Zong-You Chen, Ying Wang, Cheng-En Li, Shong-Han Pai, Chia-Wei Lin","doi":"10.1093/jom/ufad029","DOIUrl":"https://doi.org/10.1093/jom/ufad029","url":null,"abstract":"Abstract The microtube length significantly influences the convective boiling process and associated heat transfer characteristics. Other than high heat transfer, low pressure drop is also desired to improve the energy efficiency of the pumping system. This work numerically investigates the microtube length effect on heat transfer and pressure drops of convective boiling with the volume of fluid (VOF) method. The simulation results of vapor formation, heat transfer coefficient, and pressure drop are shown with different microtube lengths L = 2–20 mm. The onset of boiling is around 2 mm away from the mass flux inlet. The subcooled boiling regime can be observed between 2 and 10 mm. Three distinct regimes, liquid single-phase flow, bubbly flow, and plug flow, are shown in the longer microtubes (L = 15 mm and 20 mm). It is found that shorter microtubes can lead to less bubble formation with higher heat transfer and lower pressure drop. The average heat transfer coefficient can achieve 2432 W/(m2K) with a lower quasi-steady total pressure drop Δp|total of 32.8 Pa inside a 2-mm-long microtube. This work offers a detailed study of the impact of microtube length on convective boiling, along with pertinent physical insights. It may serve as an indicator for future microscale heat transfer application designs.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135211540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An investigation on the evolution of strain localization zone in metallic materials based on tensile tests and a 1-D nonlocal model 基于拉伸试验和一维非局部模型的金属材料应变局部化区演化研究

4区工程技术

Journal of Mechanics Pub Date : 2023-01-01 DOI: 10.1093/jom/ufad024

Wei Chen, Lizhi Xia, Yin Yao

{"title":"An investigation on the evolution of strain localization zone in metallic materials based on tensile tests and a 1-D nonlocal model","authors":"Wei Chen, Lizhi Xia, Yin Yao","doi":"10.1093/jom/ufad024","DOIUrl":"https://doi.org/10.1093/jom/ufad024","url":null,"abstract":"Abstract Metallic materials exhibit pronounced strain localization during damage and failure, posing a challenge in damage mechanics when predicting the change in the size of the strain localization zone. In this study, uniaxial tensile tests were carried out to observe changes in the size of the strain localization zone during the loading of aluminum and low-carbon steel. The initial and final states of the two metallic materials during deformation localization were compared. The strain localization zone shrank gradually with the increase in the load, which agrees with existing electronic speckle pattern interferometry (ESPI) results. This experimental phenomenon was further analyzed theoretically. By establishing the relationship between the material characteristic length and the damage, the variation of the material characteristic length was revealed, and the form of the nonlocal kernel function with a varying characteristic length was determined. The results demonstrated that within the framework of nonlocal damage theory, the nonlocal kernel function with a varying characteristic length can be used to satisfactorily simulate the gradual shrinkage of the strain localization zone of metallic materials with the damage evolution. Therefore, this study provides an effective theoretical tool for predicting the size of the strain localization zone.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135550048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analytical and numerical investigation on the effects of landslide acceleration in landslide-generated tsunamis 滑坡引发海啸中滑坡加速效应的分析与数值研究

4区工程技术

Journal of Mechanics Pub Date : 2023-01-01 DOI: 10.1093/jom/ufad025

Peter H-Y Lo, I-Chi Chan

{"title":"Analytical and numerical investigation on the effects of landslide acceleration in landslide-generated tsunamis","authors":"Peter H-Y Lo, I-Chi Chan","doi":"10.1093/jom/ufad025","DOIUrl":"https://doi.org/10.1093/jom/ufad025","url":null,"abstract":"Abstract Submarine landslides are capable of causing locally catastrophic tsunamis. A landslide necessarily begins its motion by accelerating from a halt. However, the role of landslide acceleration on the tsunami generated by a landslide remains understudied. Assuming an idealized configuration, in this study we cast the landslide acceleration problem as an extension to the existing knowledge on landslide-generated tsunamis above a flat sea bottom. By using the Green’s function approach, we derived new analytical solutions for the tsunami generated by an accelerating submarine landslide. Consistent with the observations in existing studies, we found that a slower landslide acceleration results in a longer but smaller leading submarine landslide tsunami wave. Based on a large number of numerical simulations, empirical formulas were established to quantify the wave modification factors due to landslide acceleration. Combining existing analytical solutions and the newly determined empirical formulas, we assembled semi-analytical solutions that can be easily used to predict the characteristics of the tsunami generated by an accelerating submarine landslide.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135653641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0