scholarly journals A Novel Versatile Approach for Underwater Conformal Volumetric Array Design

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3591
Author(s):  
Taofeek Ayotunde Yusuf ◽  
Seonghun Pyo ◽  
Yongrae Roh

In this study, we present a novel approach to the design of a conformal volumetric array composed of M × N convex subarrays in two orthogonal curvilinear directions for underwater acoustic imaging for mine detection. Our design targets require that the proposed array transducer has three-dimensional half-power beamwidths of 85° and 25° in either of its convex subarray parts, while also reaching a peak transmitting voltage response above 147 dB. The radiated sound pressure of the subarrays was independently derived as a function of their geometrical parameters. The resulting directional factors were then combined to analyze the beam profile of the entire array. The design was finally optimized to minimize the ripple level. To validate this theoretical design, the structure was modeled and analyzed using the finite element method. The comparison between the resulting beam pattern from the finite element analysis and the analytical computation showed an excellent compliance. The method advanced is a simple and systematic analytical model to facilitate the development of new conformal volumetric arrays for underwater mine detection.

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.


2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.


2012 ◽  
Vol 562-564 ◽  
pp. 1943-1946
Author(s):  
Yong Hu ◽  
Jin Gan Song ◽  
Qing Zou ◽  
Ke Zhu ◽  
Xiao Long Wang

Because both of the volume and the weight of the photoelectric platform are small, the structure of two frames and two axes is used in the photoelectric platform. As the key component of the photoelectric platform, the main frame should have sufficient strength and rigidity. In order to achieve this object, three-dimensional entity model of the main frame is established using CATIA software. Then the finite-element analysis of the model is finished with ANSYS Workbench. Based on the analysis results, the weak links of the main frame is found. Then these links are improved and the main frame is analyzed again. After improving the structure, the results of the finite-element analysis show that the main frame meets the requirements of design and has perfect overall performance.


2014 ◽  
Vol 614 ◽  
pp. 576-579
Author(s):  
Xiu Hua Ma

In this paper, SolidWorks2012 was redeveloped by visual programming tool Visual Basic6.0 to realize the three-dimensional parametric design of wellhead gate valve and the transformation of corresponding engineering drawings on the engineering diagram template. Then the finite element analysis was progressed directly by using the SolidWorks module of the finite element analysis. This can shorten design time of gate valve and improve work efficiency.


2010 ◽  
Vol 139-141 ◽  
pp. 2291-2294
Author(s):  
Yun Dian Zhang ◽  
Bing Zhang

Cylinder with multiple diagonal slits is one of the core parts of longitudinal-torsional resonance ultrasonic device. Its structure was more complex, the traditional processing processed it very difficult, and the traditional analytical methods were also difficult to make accurate description to system. The paper researched cylinder with multiple diagonal slits using experimental method, analysis of electrical discharge machining forming tools of the slits and three-dimensional modeling; developed cylinder with multiple diagonal slits, analyzed longitudinal-torsional resonance and mechanical properties of cylinder with multiple diagonal slits using finite element analysis method. Tested resonant frequency of cylinder with multiple diagonal slits with precision impedance analyzer. The finite element analysis results compared with tested results, and analysis of error between them, finite element analysis results slightly lower than the test results but the error was within the allowed range. Comparison of results and analysis of error indicated that developed cylinder with multiple diagonal slits meet requirement.


2012 ◽  
Vol 591-593 ◽  
pp. 841-844
Author(s):  
Ping Tang ◽  
Chun Hua Pan

Using the mechanical design of the software Solid works to established the 280 t LF the ladle furnace transportation car frame three dimensional model, and by using the finite element analysis of software Cosmos/works to static analysis for the frames, revealing that the frame of structure stress and strain distribution map of the frame, and also reveals that dangerous points and dangerous sections. Using resistance strain gauge to measure 280 t ladle transportation car frame, it is concluded that the frame of stress and strain distributions. Through the electrical measurement test the results were compared with finite element analysis results, further proof that the finite element analysis of the accuracy of the results provides theory basis for the optimization design of the frames.


Author(s):  
Jingheng Shu ◽  
Haotian Luo ◽  
Yuanli Zhang ◽  
Zhan Liu

Contacts used in finite element (FE) models were considered as the best simulation for interactions in the temporomandibular joint (TMJ). However, the precision of simulations should be validated through experiments. Three-dimensional (3D) printing models with the high geometric and loading similarities of the individuals were used in the validation. This study aimed to validate the FE models of the TMJ using 3D printing models. Five asymptomatic subjects were recruited in this study. 3D models of mandible, disc, and maxilla were reconstructed according to cone-beam CT (CBCT) image data. PLA was chosen for 3D printing models from bottom to top. Five pressure forces corresponding to the central occlusion were applied to the 3D printing models. Ten strain rosettes were distributed on the mandible to record the horizontal and vertical strains. Contact was used in the FE models with the same geometries, material properties, loadings, and boundary conditions as 3D printing models to simulate the interaction of the disc-condyle, disc-temporal bone, and upper-lower dentition. The differences of the simulated and experimental results for each sample were less than 5% (maximum 4.92%) under all five loadings. In conclusion, it was accurate to use contact to simulate the interactions in TMJs and upper-lower dentition.


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