检索范围:
排序: 展示方式:
Modeling of dynamic response of poroelastic soil layers under wave loading
Mehmet Bar?? Can üLKER
《结构与土木工程前沿(英文)》 2014年 第8卷 第1期 页码 1-18 doi: 10.1007/s11709-014-0233-2
关键词: dynamic response of soils coupled flow-deformation finite elements analytical solution harmonic waves
Evaluation of the harmonic scalpel in open surgery for abdominal aortic aneurysm
null
《医学前沿(英文)》 2012年 第6卷 第1期 页码 85-88 doi: 10.1007/s11684-012-0174-x
The harmonic scalpel is a hemostatic device primarily designed for use in laparoscopic surgery. During the last few years, many surgeons have begun to use the harmonic scalpel in open surgery. Several papers have cited the benefits of the device compared with conventional knot-tying techniques; however, no evidence showing the advantages of using the harmonic scalpel in complicated abdominal aortic aneurysm (AAA) surgery has been presented. The aim of the present study is to determine the value of the harmonic scalpel in open operation for AAA. A total of 153 patients who underwent open surgery for AAA at the Department of Vascular Surgery of Guangdong General Hospital, China between January 2001 and December 2010, were retrospectively analyzed. Open surgery performed with the harmonic scalpel on 105 patients was compared with open operation using conventional knot-tying techniques on 48 patients. The operative time, intraoperative blood loss, total postoperative drainage fluid volumes, hospital stay, and postoperative complications between the two groups were compared. The harmonic scalpel group was associated with a shorter operation time (113.2±23.6 min vs. 232.1±39.2 min, P<0.01) and lower intraoperative blood loss (126.1±96.6 ml vs. 592.1±207.2 ml, P<0.01). Postoperative drainage fluid volumes were greater in the conventional surgery group than in the harmonic scalpel group (702.1±192.8 ml vs. 198.5±97.4 ml, P<0.01). The hospital stay was shorter for the harmonic scalpel group than for the conventional surgery group (10.7±3.3 d vs. 16.5±4.7 d, P<0.05). No differences between the postoperative complications or hospital mortality of the two groups were found. The harmonic scalpel is a safe and minimally invasive tool in open surgery for AAA and is associated with shorter operative time, shorter hospital stay, and lower intraoperative blood loss and postoperative drainage fluid volumes compared with conventional knot-tying techniques.
关键词: abdominal aortic aneurysm harmonic scalpel minimally invasive
An investigation into the vibration of harmonic drive systems
M. Masoumi, H. Alimohammadi
《机械工程前沿(英文)》 2013年 第8卷 第4期 页码 409-419 doi: 10.1007/s11465-013-0275-5
Harmonic drive systems are precise and specific transmission gear systems which are beneficial in terms of the high transmission ratio and almost zero backlash. These inherent and spectacular properties result in using this mechanism in robotic and space sciences where the precision and lightwieght play an important role. This paper presents a vibration analysis of harmonic drive systems using the shell theory. Equations of vibration for the flexspline and the circular spline of the system are derived and used to find the natural frequencies for both parts and, moreover, vibration response of the system under the operating condition is calculated. Also, obtained vibration equations are utilized to study the effects of different involved parameters such as the geometry of the flexspline and its gear tooth, eccentricity, and unbalancing on the vibrational behavior of the system.
关键词: harmonic drive system strain wave gearing mechanism vibration analysis natural frequencies
Multi-harmonic forced vibration and resonance of simple beams to moving vehicles
《结构与土木工程前沿(英文)》 页码 981-993 doi: 10.1007/s11709-023-0979-5
关键词: forced vibration linear Euler beam moving load harmonic structure frequency modulation end restraints
《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0674-6
关键词: harmonic drive meshing flexibility matrix meshing force loading backlash flexspline contact analysis
Mohammad Javad REZVANIL, Mohammad Hossein KARGARNOVIN, Davood YOUNESIAN
《机械工程前沿(英文)》 2011年 第6卷 第4期 页码 409-418 doi: 10.1007/s11465-011-0245-8
The response of an infinite Timoshenko beam subjected to a harmonic moving load based on the third-order shear deformation theory (TSDT) is studied. The beam is made of laminated composite, and located on a Pasternak viscoelastic foundation. By using the principle of total minimum potential energy, the governing partial differential equations of motion are obtained. The solution is directed to compute the deflection and bending moment distribution along the length of the beam. Also, the effects of two types of composite materials, stiffness and shear layer viscosity coefficients of foundation, velocity and frequency of the moving load over the beam response are studied. In order to demonstrate the accuracy of the present method, the results TSDT are compared with the previously obtained results based on first-order shear deformation theory, with which good agreements are observed.
关键词: timoshenko composite beam pasternak viscoelastic foundation third-order shear deformation theory (TSDT) harmonic moving load
《结构与土木工程前沿(英文)》 2023年 第17卷 第1期 页码 10-24 doi: 10.1007/s11709-022-0904-3
关键词: underground structures seismic response stiffness matrix method domain reduction method P-SV waves
Effect of harmonic distortion on electric energy meters of different metrological principles
Illia DIAHOVCHENKO, Vitalii VOLOKHIN, Victoria KUROCHKINA, Michal ŠPES, Michal KOSTEREC
《能源前沿(英文)》 2019年 第13卷 第2期 页码 377-385 doi: 10.1007/s11708-018-0571-1
关键词: current distortion electric energy meter harmonics power quality
Ribbon bridge in waves based on hydroelasticity theory
Cong WANG, Shixiao FU, Weicheng CUI
《结构与土木工程前沿(英文)》 2009年 第3卷 第1期 页码 57-62 doi: 10.1007/s11709-009-0005-6
关键词: hydroelasticity ribbon bridge wave finite element method (FEM)
钟光复,王志亮,李永池
《中国工程科学》 2006年 第8卷 第5期 页码 58-62
地下球形药包爆轰后将产生很强的地震波,其传播受到多种因素的影响。把岩石介质的弹塑性帽盖模型耦合到有限差分法程序中,对一维爆轰波在非均质岩石体中的传播、演化机理进行了数值模拟与分析;着重探讨了一维应力波从“硬”岩石层进入“软”岩石层、从“软”岩石层进入“硬”岩石层时,波在形状和强度等方面的变化规律;同时探讨了岩石介质中存在的“软弱夹层”对一维应力波传播的影响。
《结构与土木工程前沿(英文)》 2022年 第16卷 第12期 页码 1530-1551 doi: 10.1007/s11709-022-0900-7
关键词: oblique incident waves critical angle half-space finite/infinite element approach seismic response analysis
Yixian LI; Limin SUN; Wang ZHU; Wei ZHANG
《结构与土木工程前沿(英文)》 2022年 第16卷 第4期 页码 448-460 doi: 10.1007/s11709-022-0805-5
关键词: dynamic stiffness principal component analysis response reconstruction damage localization under-determined equation
Hanlong LIU, Xuanming DING
《结构与土木工程前沿(英文)》 2009年 第3卷 第2期 页码 240-240 doi: 10.1007/s11709-009-0100-8
赵国泽,陆建勋
《中国工程科学》 2003年 第5卷 第10期 页码 27-33
由人工产生大功率超低频(SLF)电磁波可以在地面很大范围的许多测点同时测量该信号,利用它可以研究地下电阻率结构和空间电磁场;研究地震等引起的电磁场异常变化;探测地壳结构和地下资源,具有广阔的应用前景和发展潜力。在北京等地区的观测表明,SLF信号的功率谱密度超过天然场源信号数倍以上,所得到的视电阻率数据精度远高于天然源方法,并有长时间的稳定性。在试验测量期间距测点约120 km发生的迁安4.2级地震与观测的电磁场异常和视电阻率的变化有较好的对应性,对产生这些变化的可能的成因机制进行了分析和探讨。
关键词: 超低频/极低频电磁波 电磁异常 电阻率 地震监测
Bing LI,Xu GENG,Tong LU,Lei QIANG,Minghang LI
《机械工程前沿(英文)》 2015年 第10卷 第4期 页码 380-391 doi: 10.1007/s11465-015-0365-7
The interface wave traveling along the boundary of two materials has been studied for nearly a century. However, experiments, engineering applications, and interface wave applications to the non-destructive inspection of interlaminar composite have developed slowly. In this research, an experiment that applies Stoneley waves (a type of interfacial wave between two solid half-spaces) is implemented to detect the damage in a multilayer structure. The feasibility of this method is also verified. First, the wave velocity and wave structure of Stoneley waves at a perfectly bonded aluminum-steel interface are obtained by solving the Stoneley wave dispersion equation of two elastic half-spaces. Thereafter, an experiment is conducted to measure the Stoneley wave velocity of an aluminum-steel laminated beam and to locate interlaminar cracks by referring to the Stoneley wave velocity and echo wave time. Results indicate that the location error is less than 2%. Therefore, Stoneley waves show great potential as a non-destructive inspection method of a multilayer structure.
关键词: crack localization interface waves Stoneley waves interlaminar damage multilayer structure
标题 作者 时间 类型 操作
Modeling of dynamic response of poroelastic soil layers under wave loading
Mehmet Bar?? Can üLKER
期刊论文
Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading
期刊论文
Dynamic analysis of composite beam subjected to harmonic moving load based on the third-order shear deformation
Mohammad Javad REZVANIL, Mohammad Hossein KARGARNOVIN, Davood YOUNESIAN
期刊论文
A numerical framework for underground structures in layered ground under inclined P-SV waves using stiffness
期刊论文
Effect of harmonic distortion on electric energy meters of different metrological principles
Illia DIAHOVCHENKO, Vitalii VOLOKHIN, Victoria KUROCHKINA, Michal ŠPES, Michal KOSTEREC
期刊论文
Soil seismic analysis for 2D oblique incident waves using exact free-field responses by frequency-based
期刊论文
A dynamic stiffness-based framework for harmonic input estimation and response reconstruction considering
Yixian LI; Limin SUN; Wang ZHU; Wei ZHANG
期刊论文
Propagation characteristics of transient waves in low-strain integrity testing on cast-in-situ concrete
Hanlong LIU, Xuanming DING
期刊论文