scholarly journals Safety Evaluation of Hyperbolic Arch Aqueduct Using Three-Dimensional Laser Scanning and Finite Element Analysis

2020 ◽  
Vol 143 ◽  
pp. 01001
Author(s):  
Chengfa Deng ◽  
Chang Xu ◽  
Qi Xie ◽  
Qiang Peng

The safety evaluation of the aqueduct in many years of operation is often performed to determine the structural operational behaviour so as to provide a scientific basis for further reinforcement or reconstruction. The missing of the original design data due to the long construction period provides great challenging in the structural safety evaluation of the aqueduct. Taking a hyperbolic arch aqueduct in China as an example, we first rebuilt the aqueduct model using the three-dimensional (3D) point cloud from the three-dimensional laser scanning technology. Coupled with the on-site safety inspection, the 3D finite element analysis was then performed to learn the stress performance of the aqueduct body and its supporting structures, so as to achieve the purpose of safety evaluation of aqueduct structure in a whole.

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


2012 ◽  
Vol 24 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Yu-Chi Chen ◽  
Wen-Ching Ko ◽  
Han-Lung Chen ◽  
Hsu-Ching Liao ◽  
Wen-Jong Wu ◽  
...  

We propose a model to give us a method to investigate the characteristic three-dimensional directivity in an arbitrarily configured flexible electret-based loudspeaker. In recent years, novel electret loudspeakers have attracted much interest due to their being lightweight, paper thin, and possessing excellent mid- to high-frequency responses. Increasing or decreasing the directivity of an electret loudspeaker makes it excellent for adoption to many applications, especially for directing sound to a particular area or specific audio location. Herein, we detail a novel electret loudspeaker that possesses various directivities and is based on various structures of spacers instead of having to use multichannel amplifiers and a complicated digital control system. In order to study the directivity of an electret loudspeaker based on an array structure which can be adopted for various applications, the horizontal and vertical polar directivity characteristics as a function of frequency were simulated by a finite-element analysis model. To validate the finite-element analysis model, the beam pattern of the electret loudspeaker was measured in an anechoic room. Both the simulated and experimental results are detailed in this article to validate the various assertions related to the directivity of electret cell-based smart speakers.


Sign in / Sign up

Export Citation Format

Share Document