scholarly journals Acoustics on small scales

Author(s):  
Florian Toth ◽  
Hamideh Hassanpour Guilvaiee ◽  
Georg Jank

AbstractWe present a modelling strategy based on the finite element method to describe flexible, piezoelectric structures surrounded by a compressible fluid, including viscosity. Non-conforming interfaces based on the Mortar method are used to couple the different physical domains. Finally, we present an application example of a piezoelectrically actuated MEMS structure to illustrate the modeling procedure and the impact of viscous effects.

2018 ◽  
Vol 196 ◽  
pp. 01055
Author(s):  
Sławomir Dudziak ◽  
Zofia Kozyra

Dynamic analyses play an important role in the process of designing buildings in the vicinity of transportation routes. The Finite Element Method is the most popular modelling technique, because it allows to simulate the structure response in the higher frequency range properly. However, the results of such analyses depend on many factors and can differ a lot. This paper discusses the impact of the building mass estimation and neglecting or including damping in the analysis on the assessment of influence of vibrations due to traffic on people.


2012 ◽  
Vol 190-191 ◽  
pp. 23-27
Author(s):  
Jin Sha ◽  
Zhi Yuan Yao ◽  
Yang Jiao

This paper proposes an ultrasonic knife system for MEMS packaging. The ultrasonic knife system is consisted of an ultrasonic transducer, a cutter and a gripper feeder. The ultrasonic transducer engenders high frequency vibration, which lead to the resonance of the structure. Amplitude transformer can magnify the amplitude. By the impact and collision of the cutter, the material can be cut through, and the high temperature created by high-frequency vibration can do the welding. The structure is designed and optimized by the finite element method, and a model machine is produced. According to the experimental results, the ultrasonic knife system has the virtues of high cutting force and better wedding feature, which are suitable for MEMS packaging.


2009 ◽  
Vol 294 ◽  
pp. 27-38 ◽  
Author(s):  
Fabian Ferrano ◽  
Marco Speich ◽  
Wolfgang Rimkus ◽  
Markus Merkel ◽  
Andreas Öchsner

This paper investigates the mechanical properties of a new type of hollow sphere structure. For this new type, the sphere shell is perforated by several holes in order to open up the inner sphere volume and surface. The mechanical behaviour of perforated sphere structures under large deformations and strains in a primitive cubic arrangement is numerically evaluated by using the finite element method for different hole diameters and different joining techniques.


2012 ◽  
Vol 594-597 ◽  
pp. 387-390
Author(s):  
Yu Hu ◽  
Qiang Feng

With the saturated - unsaturated seepage theory, Hualianshu landslide is seepage numerical simulated by the finite element method .The changes of Hualianshu landslide seepage are subject to the impact of rainfall and reservoir water level's changes.The formation and variation of the slope seepage field under rainfall infiltration have been come to, providing a basis for analysis of slope stability and landslide prediction.


2013 ◽  
Vol 368-370 ◽  
pp. 756-759
Author(s):  
Jing Ma ◽  
Wen Sheng Chen ◽  
Xue Feng Hu

Based on the Finite Element Method ,a model has been built to study the impact of rigid pile composite foundation with lateral unloading,then obtained a conclusion about the horizontal displacement during excavating.


Author(s):  
Jan Steininger ◽  
Stefan Medvecky ◽  
Robert Kohar ◽  
Tomas Capak

The article deals with an optimization procedure of roller elements geometry with regard to durability of spherical roller bearings. The aim of the article is to examine the impact of change of the roller elements inner geometry on durability and reliability of spherical roller bearings; the contact strain along a spherical roller by means of the Finite Element Method at contact points of components of a spherical roller bearing by means of designed 3D parametric models. The most appropriate shape of roller elements inner geometry of a bearing from the standpoint of calculated durability was determined based on results of the contact analyses.


2021 ◽  
Vol 26 (3-4) ◽  
pp. 255-264
Author(s):  
E.Y. Chugunov ◽  
◽  
A.I. Pogalov ◽  
S.P. Timoshenkov ◽  
◽  
...  

In the context of increasing the electronic components integration level, growing functionality and packaging density, as well as reducing the electronics weight and size, an integrated approach to engineering calculations of parts and assemblies of modern functionally and technically complex microelectronic products is required. Of particular importance are engineering calculations and structural modeling using computer-aided engineering systems, and also assessment of structural, technological and operational factors’ impact on the products reliability and performance. This work presents an approach to engineering calculations and microelectronic products modeling based on the finite-element method providing a comprehensive account of various factors (material properties, external loading, temperature fields, and other parameters) impact on the stress-strain state, mechanical strength, thermal condition, and other characteristics of products. On the example of parts and assemblies of products of microelectronic technology, the approximation of structures was shown and computer finite-element models were developed to study various structural and technological options of products and the effects on them. Engineering calculations and modeling of parts and assemblies were performed, taking into account the impact of material properties, design parameters and external influences on the products’ characteristics. Scientific and technical recommendations for structure optimization and design and technology solutions ensuring the products resistance to diverse effects were developed. It has been shown that an integrated approach to engineering calculations and microelectronic products modeling based on the finite-element method provides for the determination of optimal solutions taking into account structural, technological, and operational factors and allows the development of products with high tactical, technical and operational characteristics.


2018 ◽  
Vol 49 ◽  
pp. 00073 ◽  
Author(s):  
Michał Musiał

This article presents the results of experimental research, carried out on the elements of vertical and internal blinds, containing phase-change material in its. The research was aimed at determining the significance of such factors as: ambient temperature, shape of profiles containing PCM and the intensity of their heating to the actual amount of energy required for complete melting of PCM Samples of aluminum profiles of various cross-sectional shapes containing commercial RT 28 phase-changing material. The author carried out the research presented below on the basis of a poly-selective orthogonal plan. The analysis was performed using the finite element method, in the Statistica 12 program. The obtained effects of the performed tests and the conducted analysis enabled an independent statistical evaluation of the factors of the approximate polynomial.


1995 ◽  
Vol 117 (2A) ◽  
pp. 336-342 ◽  
Author(s):  
W. H. Gau ◽  
A. A. Shabana

In rotating elastic rods, dispersions occurs as the result of the finite rotations. By using Fourier method, it can be shown that the impact-induced longitudinal waves no longer travel with the same phase velocities. Furthermore, the speeds of the wave propagation are independent of the impact conditions including the value of the coefficient of restitution. In this investigation the use of the finite element method in the analysis of impact-induced longitudinal waves in rotating elastic rods is examined. The equations of motion are developed using the principle of virtual work in dynamics. Jump discontinuity in the system velocity vector as result of impact is predicted using the generalized impulse momentum equations. The solution obtained using the finite element method is compared with the solution obtained using Fourier method. Numerical results show that there is a good agreement between the solution obtained by using Fourier method and the finite element solution in the analysis of wave motion. However, discrepancies between the two solutions in the analysis of the velocity waves are observed and discussed in this paper.


2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Saeid Kasiri ◽  
Daniel J. Kelly

Stenting of curved arteries is generally perceived to be more challenging than straight vessels. Conceptually implanting multiple shorter stents rather than a single longer stent into such a curved artery represents a promising concept, but little is known about the impact of such an approach. The objective of this study is to evaluate the effectiveness of using a multiple segment stent rather than a single long stent to dilate a curved artery using the finite element method. A double segment stent (DSS) and a single segment stent (SSS) were modeled. The stents were compared when expanded into a model of a curved artery. The model predicts that the DSS provides higher flexibility, more conformity, and lower recoil in comparison to the SSS. The volume of arterial tissue experiencing high levels of stress due to stent implantation is also reduced for the DSS. It is suggested that a multiple segment stenting system is a potential solution to the problem of higher rates of in-stent restenosis in curved arteries and mechanically challenging environments.


Sign in / Sign up

Export Citation Format

Share Document