scholarly journals Experiment and Simulation Analysis on Noise Attenuation of Al/MF Cylindrical Shells

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Bin Li ◽  
Jian Li ◽  
Shilin Yan ◽  
Wenjie Yan ◽  
Xu He

For the issue concerning internal noise reduction of Al-made cylindrical shell structure, the noise control method of laying melamine foam (MF) layer is adopted for in-shell noise attenuation experiments of Al and Al/MF cylindrical shells and corresponding internal noise response spectrograms are obtained. Based on the Virtual.Lab acoustics software, a finite element model is established for the analysis of noise in the Al/MF cylinder shell and numerical simulation computation is conducted for the acoustic mode and in-shell acoustic response; the correctness of the finite element model is verified via comparison with measured data. On this basis, influence rules of different MF laying rate and different laying thickness on acoustic cavity resonance response within the low and medium frequency range of 100–400 Hz are studied. It is indicated that noise reduction increases with MF laying rate, but the amplification decreases along with the rising of MF laying rate; noise reduction per unit thickness decreases with the increase of laying thickness, while noise reduction per unit area increases.

2020 ◽  
Vol 11 (4) ◽  
pp. 579-589
Author(s):  
Muhamad Husnain Mohd Noh ◽  
Mohd Akramin Mohd Romlay ◽  
Chuan Zun Liang ◽  
Mohd Shamil Shaari ◽  
Akiyuki Takahashi

PurposeFailure of the materials occurs once the stress intensity factor (SIF) overtakes the material fracture toughness. At this level, the crack will grow rapidly resulting in unstable crack growth until a complete fracture happens. The SIF calculation of the materials can be conducted by experimental, theoretical and numerical techniques. Prediction of SIF is crucial to ensure safety life from the material failure. The aim of the simulation study is to evaluate the accuracy of SIF prediction using finite element analysis.Design/methodology/approachThe bootstrap resampling method is employed in S-version finite element model (S-FEM) to generate the random variables in this simulation analysis. The SIF analysis studies are promoted by bootstrap S-version Finite Element Model (BootstrapS-FEM). Virtual crack closure-integral method (VCCM) is an important concept to compute the energy release rate and SIF. The semielliptical crack shape is applied with different crack shape aspect ratio in this simulation analysis. The BootstrapS-FEM produces the prediction of SIFs for tension model.FindingsThe mean of BootstrapS-FEM is calculated from 100 samples by the resampling method. The bounds are computed based on the lower and upper bounds of the hundred samples of BootstrapS-FEM. The prediction of SIFs is validated with Newman–Raju solution and deterministic S-FEM within 95 percent confidence bounds. All possible values of SIF estimation by BootstrapS-FEM are plotted in a graph. The mean of the BootstrapS-FEM is referred to as point estimation. The Newman–Raju solution and deterministic S-FEM values are within the 95 percent confidence bounds. Thus, the BootstrapS-FEM is considered valid for the prediction with less than 6 percent of percentage error.Originality/valueThe bootstrap resampling method is employed in S-FEM to generate the random variables in this simulation analysis.


2014 ◽  
Vol 900 ◽  
pp. 742-745 ◽  
Author(s):  
Yao Jie He ◽  
Bai Jing Qiu ◽  
Ya Fei Yang

In order to attenuate the deformation of spray boom, a finite element model built based on ANSYS, according to the reasults of numerical modal analysis and modal texting, the reliability of the finite element model was affirmed. Then, an isolator was introduced between spray boom and frame, a frame-isolator-spray boom model was built in ADAMS. The effect of the isolators which have different parameters was research, the reasult shows: The isolator has much effect on attenuating spray booms deformation, the stiffness of isolators spring dampers has little effect on spray booms deformation, but the damping of isolators spring dampers has effect on spray booms deformation.


2006 ◽  
Author(s):  
C. M. Mota Soares ◽  
H. Santos ◽  
C. A. Mota Soares ◽  
J. N. Reddy

2012 ◽  
Vol 151 ◽  
pp. 484-489 ◽  
Author(s):  
Jie Fang Xing ◽  
Jie Zhang ◽  
Lu Jun He

Introduce some basic knowledge, methods and theory of using the finite element software ANSYS to carry out contact analysis, and then establish the contact simulation analysis finite element model for CTP imaging drum and plate by using the software ANSYS. A numerical simulation analysis on the imaging drum and the plate indicates that the analysis results are consistent with the experimental results, so as to lay the foundation for the reliability and stability of dynamic design and optimization design of CTP imaging drum.


Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2154
Author(s):  
Vasyl Varvolik ◽  
Dmytro Prystupa ◽  
Giampaolo Buticchi ◽  
Sergei Peresada ◽  
Michael Galea ◽  
...  

To improve the design of electric drives and to better predict the system performance, numerical simulation has been widely employed. Whereas in the majority of the approaches, the machines and the power electronics are designed and simulated separately, to improve the fidelity, a co-simulation should be performed. This paper presents a complete coupled co-simulation model of synchronous reluctance machine (SynRel) drive, which includes the finite element model of the SynRel, the power electronics inverter, the control system, and application examples. The model of SynRel is based on a finite element model (FEM) using Simcenter MagNet. The power electronics inverter is built using PLECS Blockset, and the drive control model is built in Simulink environment, which allows for coupling between MagNet and PLECS. The proposed simulation model provides high accuracy thanks to the complete FEA-based model fed by actual inverter voltage. The comparison of the simulation results with experimental measurements shows good correspondence.


Author(s):  
Qiwei Yang ◽  
Derrick Tate ◽  
Sang-Wook Bae

Although a large number of crash tests have been performed between passenger cars and rigid fixed traffic signs, the number of real tests focusing on crashworthiness of portable roll-up signs is still limited. Because a standard, portable roll-up sign contains at least three kinds of dissimilar materials, such as steel for the base, fiberglass for the batten, vinyl for the sign, and because the sign’s configuration is more complicated than a rigid fixed sign, it is important to simulate the behavior of portable roll-up signs in collision. In this paper, a fine-mesh finite element model precisely representing the portable roll-up sign was created and used together with a car model to simulate the process of impact with 0 and 90 degree orientation. The simulation was performed using LS-DYNA software. Techniques for creating the finite element model were discussed. Afterwards this finite element model, being validated and verified through real tests, can be used for parametric and/or robust design.


2013 ◽  
Vol 639-640 ◽  
pp. 460-469
Author(s):  
Hai Bo Jiang ◽  
Yan Song Deng ◽  
Yun Qiu ◽  
Chun Gen Wei ◽  
Li Chen ◽  
...  

A finite element model is proposed for numerical analysis of mechanical properties of precast segmental concrete test beam with external tendons. The 3D finite element model of test beam is established by SOLID65 element in ANSYS software, while the dry joint between segments is simulated by contact element, and the attachment between concrete beam and external prestressed tendons is achieved by node coupling method. Numerical simulation analysis reveals structural behavior, stress variations and crack opening cases of joints of the test beam by considering the concrete material and geometric nonlinearity. Influencing factors of the bending mechanical properties of the test beam are researched with different tendon types, secondary effect of external tendons and external tendon slip at deviation. Results of the numerical analysis reveal that the segmental joints are in the compressive state below the 300kN.Crack opening is the key factor of the mechanical properties of the test beam above the 300kN.The results can be used for structural design of precast segmental bridge.


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