Journal of Mechanics最新文献_第8页

Comparison between overall and respective electrical rectifications in array of piezoelectric energy harvesting 压电能量收集阵列整体整流与各自整流的比较

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac039

I. Lien, Y. Lo, S. Chiu, Y. C. Shu

{"title":"Comparison between overall and respective electrical rectifications in array of piezoelectric energy harvesting","authors":"I. Lien, Y. Lo, S. Chiu, Y. C. Shu","doi":"10.1093/jom/ufac039","DOIUrl":"https://doi.org/10.1093/jom/ufac039","url":null,"abstract":"The article compares two different electrical rectifications employed by a piezoelectric harvester array. The first type consists of parallel connection of harvesters followed by an AC–DC full-bridge rectifier for overall electrical rectification. The second type allows for respective electrical rectification of each individual harvester, and then connecting them all in parallel. The former exhibits stronger electromechanical coupling effect for enhancing output power. The latter is capable of avoiding charge cancelation for improving bandwidth. The analysis of the electromechanical response of these two types is provided with full derivations for the second case. The predictions of displacement and output power are compared with the experiment and the results show good agreement. Two recommendations are offered from the present studies. First, suppose the power dissipations due to voltage gaps across the rectifiers are insignificant compared with the amount of output power realized by each individual harvester. The piezoelectric harvester array with respective electrical rectification exhibits better performance than that with the overall rectification from the broadband point of view at the cost of reducing peak power. On the contrary, if the amount of power dissipations can not be neglected or the harvester exhibits the strongly coupled electromechanical response, it is recommended to employ the harvester array allowing the mixed parallel/series connections switched by DPDT (Double-Pole Double-Throw). The array of the mixed type with overall electrical rectification exhibits performance significantly outperforming the array with respective electrical rectification from the point of view of broadband and power enhancement.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61541696","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: 2

Interaction of circular cavity and crack near anisotropic bi-material interface under SH-waves incidence sh波入射下各向异性双材料界面附近圆腔与裂纹的相互作用

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac050

Jian-wei Zhang, Guoguan Lan, Shui-mei Chen, Hua-nan Xu, Zai-lin Yang

{"title":"Interaction of circular cavity and crack near anisotropic bi-material interface under SH-waves incidence","authors":"Jian-wei Zhang, Guoguan Lan, Shui-mei Chen, Hua-nan Xu, Zai-lin Yang","doi":"10.1093/jom/ufac050","DOIUrl":"https://doi.org/10.1093/jom/ufac050","url":null,"abstract":"An anisotropic bi-material interface with a circular hollow and a crack was used to explore the scattering of SH waves using complex variables and Green's function techniques. A horizontal interface in a bi-material media forms an elastic anisotropic half-space with a circular cavity and a linear crack, whereas the other half-space is an elastic isotropic half-space. The Green's function approach is used to derive the relevant Green's functions, which are then used in the “crack division” procedure to create a crack. During the joining of the two pieces, unknown anti-plane forces are applied to the horizontal surfaces to ensure the interface maintains its continuity criteria. For weakly singular integral equations, Fredholm integral equations are inferred and solved using the direct discrete technique. The simulation results were represented graphically to show how different parameters affect the influence of dynamic stress concentration factors around the cavity and dynamic stress intensity factors toward the crack tip. For example, a cavity's wave number and angle of incidence, as well as the distance between the cavity's center and its horizontal interface and its radius, are all elements that must be taken into consideration.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61542307","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: 1

Analysis of high Reynolds free surface flows 高雷诺数自由表面流动分析

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac036

D. Young, M. C. Lin, C. Tsai

引用次数: 2

Experimental study on erosion and wear law of metal screen under spraying condition 喷淋条件下金属筛网冲蚀磨损规律试验研究

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac004

Ruomeng Ying, Xuankang Zhao, Baocheng Shi, Lijuan Wu, X. Zhang, Ziheng Jiang, Xiaochi Guo

{"title":"Experimental study on erosion and wear law of metal screen under spraying condition","authors":"Ruomeng Ying, Xuankang Zhao, Baocheng Shi, Lijuan Wu, X. Zhang, Ziheng Jiang, Xiaochi Guo","doi":"10.1093/jom/ufac004","DOIUrl":"https://doi.org/10.1093/jom/ufac004","url":null,"abstract":"It is very important for the safe production of sand producing oil and gas wells to make clear the erosion law of sand control screen pipe. The experiment of erosion law of metal mesh under two working conditions of blockage and non-blockage was carried out with jet erosion experimental device. The influencing factor of solid mass fraction (0.3%, 0.5%, and 0.8%), aperture velocity (1.5 m/s, 4 m/s, and 6 m/s) and particle size (20 μm, 54 μm, and 74 μm) on the erosion rate of metal mesh was analyzed. The results show that the mass loss of screen increases with the increase of solid mass fraction, aperture velocity and particle size, and the change law of single and double screens is consistent; under the condition of incomplete blockage, the mass loss of screen increases exponentially with the flow rate; under the condition of complete blockage, the balance flow rate of screen decreases with the increase of pressure difference when the pressure difference between inlet and outlet of screen is kept constant. In addition, the mass loss increases with the increase of pressure difference; in addition, the scanning electron microscope results of the erosion screen show that the erosion wear of the screen under the non-blocking condition is much less than that under the blocking condition, which is because the gap between the weft wires of the screen is blocked by particles, resulting in the rapid increase of the local aperture velocity of the screen, thus accelerating the local erosion wear of the screen.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61539166","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: 2

An accurate strategy for computing reaction forces and fluxes on trimmed locally refined meshes 一种精确的计算反作用力和局部精细化网格通量的策略

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac006

Davide D’Angella, S. Kollmannsberger, A. Reali, E. Rank, T. Hughes

引用次数: 4

Weight functions for an array of collinear cracks in an infinite anisotropic elastic plate 无限各向异性弹性板中共线裂纹阵列的权函数

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac011

Kuang-Chong Wu, Shyh-Haur Chen

引用次数: 1

Computational flow analysis with boundary layer and contact representation: II. Heart valve flow with leaflet contact 边界层与接触表示的计算流分析[j]。心脏瓣膜流动与小叶接触

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac013

Takuya Terahara, T. Kuraishi, K. Takizawa, T. Tezduyar

引用次数: 13

Research on a model-based burst pressure prediction method for pipelines with corrosion defects 基于模型的含腐蚀缺陷管道爆破压力预测方法研究

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac024

Hongming Zhou, Peiyuan Li, Longfei Wu

引用次数: 0

Tuning the roughness of aluminum surfaces for superrepellency and absorptivity 调整铝表面的粗糙度，以获得超强的拒水性和吸水性

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac020

Chun-Ti Chang, Andrew J Bhak, Daniel J Hanggi, Kayla M Kemler, Arnav S. Malkani, Edward W Kang

引用次数: 0

Research on reduction of residual stress in girth welds of large-diameter natural gas pipes by ultrasonic 超声消除大直径天然气管道环焊缝残余应力的研究

IF 1.7 4区工程技术

Journal of Mechanics Pub Date : 2022-01-01 DOI: 10.1093/jom/ufac038

Yukun Li, Longsheng Wang, S. Zhao, Jinglong Chang, Keren Shen, Shanyao Wang, Xiaojian Cao, Yixuan Wang

{"title":"Research on reduction of residual stress in girth welds of large-diameter natural gas pipes by ultrasonic","authors":"Yukun Li, Longsheng Wang, S. Zhao, Jinglong Chang, Keren Shen, Shanyao Wang, Xiaojian Cao, Yixuan Wang","doi":"10.1093/jom/ufac038","DOIUrl":"https://doi.org/10.1093/jom/ufac038","url":null,"abstract":"Excessive residual stress of the girth weld in pipes will directly damage the pipe strength during its operation. Accurate measurement and effective reduction of the residual stress can ensure the safety of natural gas pipes during their service. In this paper, an X80-type large-diameter natural gas pipe section with girth welds is taken as the research object. The coercive force method is used to characterize the residual stress of the girth weld and its surroundings, and then the distribution law of the residual stress of the girth weld and its surroundings is obtained based on the measurement results of the Blind-hole method; the ultrasonic impact method was used to reduce the girth weld residual stress, and the effect of the ultrasonic impact method on the residual stress reduction was studied by comparing changes of the distribution characteristics of the coercive force in the girth weld and its surroundings before and after the residual stress reduction in the natural gas pipes. Lastly, the in-situ test specimen is made to carry out the uniaxial tensile test so as to study the effect of the ultrasonic impact method on the tensile mechanical properties of pipe welds. This study clarifies the influence law of the ultrasonic impact on the mechanical properties of weld toe materials, and provided technical theoretical guidance for the reduction of field residual stress in natural gas pipes.","PeriodicalId":50136,"journal":{"name":"Journal of Mechanics","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61541371","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: 1