The Experts below are selected from a list of 678264 Experts worldwide ranked by ideXlab platform
Usik Lee - One of the best experts on this subject based on the ideXlab platform.
Applied Mechanics and Materials, 2012Co-Authors: Usik Lee, Il Wook Park, In Joon JangAbstract:
This paper presents a spectral Element Model for the laminated composite beams with a surface-bonded PZT layer. The spectral Element Model represented by exact dynamic stiffness matrix is derived in the frequency-domain by using the frequency-dependent dynamic shape functions which are formulated from the free wave solutions satisfying the governing differential equations transformed into the frequency-domain by using the DFT theory. The performance of the present spectral Element Model is then evaluated by comparing its solutions with those obtained by using the conventional finite Element Model
50th AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference, 2009Co-Authors: Jungsik Choi, Jaesang Lee, Usik LeeAbstract:
A spectral Element Model for the spinning shafts with thick rigid disks is developed. The spinning shafts supported by bearings are represented by the uniform Timoshenko shaft Models and the disks are considered to be wobbling about their centers. The bearings are represented by two translational springs and two rotational springs. The mass unbalances of disks are taken into account in the spectral Element Model. The spectral Element Model is then used to investigate the critical speeds and dynamic characteristic of the spinning Timoshenko shafts with and without the disk.
Engineering Structures, 2003Co-Authors: Usik LeeAbstract:
Abstract The pipelines conveying high velocity internal flow may experience severe flow-induced vibrations due to the fluid–pipeline interaction. For accurate prediction of the flow-induced vibrations, this paper develops a spectral Element Model for the pipeline conveying steady internal fluid. The spectral Element Model is represented by the exact dynamic stiffness matrix, which is formulated from the wave solutions satisfying the governing structural dynamic equations through the dispersion relation. In contrast with the classical finite Element Model, the spectral Element Model can provide very accurate solutions using only one finite Element for the uniform structure member, regardless of its length. To investigate the advantage of the present spectral Element Model over the conventional finite Element Model, the spectral Element vibration analysis is conducted for a simply supported straight pipeline conveying internal steady flow.
Jan J. Schreuder - One of the best experts on this subject based on the ideXlab platform.
Journal of Applied Physiology, 1993Co-Authors: Karel H. Wesseling, Jos R. C. Jansen, Jos J Settels, Jan J. SchreuderAbstract:
We computed aortic flow pulsations from arterial pressure by simulating a nonlinear, time-varying three-Element Model of aortic input impedance. The Model Elements represent aortic characteristic i...
W.d. Rolph - One of the best experts on this subject based on the ideXlab platform.
Requirements for finite Element Model generation from CAD data—An approach using numerical conformal mappingComputers & Structures, 1995Co-Authors: W.d. RolphAbstract:
A critical problem facing the mechanical design community is that of bridging the gap between mechanical CAD data (typically boundary rep trimmed NURB surfaces) and finite Element Models. A number of papers have discussed this issue and identified it as a critical technology for developing future mechanical design methodologies [Crabb, In Implementation Road Map for Design and Manufacturing, D. H. Brown Sponsored Conference, Ann Arbor, MI (1994)]. While a variety of procedures for finite Element Model generation from CAD data have been proposed and commercialized, the resulting Models have, in general, received much resistance from the professional analyst community. A set of criteria by which the quality of a proposed finite Element Model generation procedure can be evaluated analytically using Elementary control theory is discussed. Additional observations of mesh behavior based on the dimensional anisotropy of general geometric components are presented. Finally a criterion for qualitatively evaluating optimal edge orientations for many of the classical Element families is discussed. It is suggested that a combination of these approaches provides an opportunity to semi-quantitatively rank order proposed finite Element Model generation procedures. A finite Element Model generation procedure based on numerical conformal mapping is then proposed. It is demonstrated that this procedure ranks very highly when evaluated against the previous criteria. Further, a technical proof of concept implementation demonstrates that numerical conformal mapping appears to be suitable for application to a wide variety of boundary rep solid Models.
Zhang Ya-qing - One of the best experts on this subject based on the ideXlab platform.
Chinese Journal of Conservative Dentistry, 2007Co-Authors: Zhang Ya-qingAbstract:
AIM: To construct a three-dimensional(3D)finite Element Model of the maxillary first molar root system and provide a digital Model for analysing the biomechanical properties of the molar. METHODS: Micro-CT scanning technology was used in combination with medical images reconstruction software and RE(reverse engineering) software. Dependability of the Model was testified. RESULTS: An ideal three-dimensional finite Element Model of the maxillary first molar root systerm in vitro was constructed, which can provid a basis for the future research of its biomechanical characteristics. CONCLUSION: The constructed 3-DFE of the maxillary first molar root system in vitro Model was feasible and effective and could be applied in the stress analysis of denture and teeth.
The construction of the three-dimensional finite Element Model and analog analysis of the maxillary first molar after RCTJournal of Clinical Stomatology, 2007Co-Authors: Zhang Ya-qingAbstract:
Objective:To construct a three-dimensional(3D)finite Element Model of the maxillary first molar and provide a digital Model for analysing the biomechanical properties of the molar.Method:Micro-CT scanning technology was used in combination with medical images reconstruction software and RE(reverse engineering)software,and Ansys Dependability of the Model was testified.Result:An ideal three-dimensional finite Element Model of the maxillary first molar after RCT in vitro was constructed,which provided a basis for the future research of its biomechanical characteristics.Conclusion:The constructed 3-D FE the maxillary first molar after RCT in vitro Model was feasible and effective and it could be applied in the stress analysis of denture and teeth.
D J Ewins - One of the best experts on this subject based on the ideXlab platform.
finite Element Model updating using frequency response function data ii case study on a medium size finite Element ModelMechanical Systems and Signal Processing, 1995Co-Authors: M Imregun, Kenan Y Sanliturk, D J EwinsAbstract:
Abstract This work reports findings from a case study which is aimed at updating a medium-size finite Element Model using frequency response function (FRF) data. The numerical stability of the method and its applicability to true measured FRF data were investigated in the case of a plate-beam structure which was Modeled using about 500 dof. The initial finite Element Model of the structure was found to be in fairly good agreement with measured data, a feature which allowed a systematic evaluation of various factors affecting the quality of Model updating. After several attempts, it was possible to update the initial FRFs so that they matched the measured ones within engineering accuracy. However, the non-uniqueness of the updated Model became apparent since it was possible to find several such Models, the FRFs of each of which satisfied the basic matching criterion.