The Effect of the Cavity Damping on Vehicular Evaluation using the Finite Element Method

2016 ◽  
Vol 41 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Tiago S. Ferreira ◽  
Pedro A. Magalhães ◽  
Frederico L. Moura ◽  
Timoteo S. Ferreira
Keyword(s):  
Automotive Industry ◽  
Development Stage ◽  
The Finite Element Method ◽  
Acoustic Performance ◽  
Numerical Studies ◽  
Variable Function ◽  
Experimental Parameters ◽  
Experimental Correlation ◽  
Parameter Values ◽  
Cavity Damping

Abstract This work focuses on finding a numerical solution for vehicle acoustic studies and improving the usefulness of the numerical experimental parameters for the development stage of a new automotive project. Specifically, this research addresses the importance of modal cavity damping for vehicle exerts during numerical studies. It then seeks to suggest standardized parameter values of modal cavity damping in vehicular acoustic studies. The standardized value of modal cavity damping is of great importance for the study of vehicular acoustics in the automotive industry because it would allow the industry to begin studies of the acoustic performance of a new vehicle early in the conception phase with a reliable estimation that would be close to the final value measured in the design phase. It is common for the automotive industry to achieve good levels of numerical-experimental correlation in acoustic studies after the prototyping phase because this phase can be studied with feedback from the simulation and experimental modal parameters. Thus, this research suggests values for modal cavity damping, which are divided into two parts due to their behaviour: ξ(x) = −0.0126(x − 100) + 6.15 as a variable function to analyse up to 100 Hz and 6.15% of modal cavity damping constant for studies between 30 Hz and 100 Hz. The sequence of this study shows how we arrived at these values.

scholarly journals A Metawindow with Optimised Acoustic and Ventilation Performance

2021 ◽  
Vol 11 (7) ◽  
pp. 3168
Author(s):  
Gioia Fusaro ◽  
Xiang Yu ◽  
Zhenbo Lu ◽  
Fangsen Cui ◽  
Jian Kang
Keyword(s):  
Natural Ventilation ◽  
Noise Control ◽  
Fem Analysis ◽  
The Finite Element Method ◽  
Noise Mitigation ◽  
Acoustic Performance ◽  
Potential Applications ◽  
Ventilation Performance ◽  
Sound Reduction ◽  
Window Design

Crucial factors in window performance, such as natural ventilation and noise control, are generally conceived separately, forcing users to choose one over the other. To solve this dualism, this study aimed to develop an acoustic metamaterial (AMM) ergonomic window design to allow noise control without dependence on the natural ventilation duration and vice versa. First, the finite element method (FEM) was used to investigate the noise control performance of the acoustic metawindow (AMW) unit, followed by anechoic chamber testing, which also served as the validation of the FEM models. Furthermore, FEM analysis was used to optimise the acoustic performance and assess the ventilation potential. The numerical and experimental results exhibited an overall mean sound reduction of 15 dB within a bandwidth of 380 to 5000 Hz. A good agreement between the measured and numerical results was obtained, with a mean variation of 30%. Therefore, the AMW unit optimised acoustic performance, resulting in a higher noise reduction, especially from 50 to 500 Hz. Finally, most of the AMW unit configurations are suitable for natural ventilation, and a dynamic tuned ventilation capacity can be achieved for particular ranges by adjusting the window’s ventilation opening. The proposed designs have potential applications in building acoustics and engineering where natural ventilation and noise mitigation are required to meet regulations simultaneously.

scholarly journals Investigations on Torsion of the Two-Chords Single Laced Members

2017 ◽  
Vol 25 (2) ◽  
pp. 147-160
Author(s):  
Paweł Lorkowski ◽  
Bronisław Gosowski
Keyword(s):  
Cross Sections ◽  
Experimental Studies ◽  
The Finite Element Method ◽  
Second Moment ◽  
Steel Columns ◽  
Numerical Studies ◽  
Traction Network ◽  
Railway Traction ◽  
Parametric Analyses ◽  
The Relationship

Abstract The paper presents experimental and numerical studies to determine the equivalent second moment of area of the uniform torsion of the two-chord steel single laced members. The members are used as poles of railway traction network gates, and steel columns of framed buildings as well. The stiffness of uniform torsion of this kind of columns allows to the determine the critical loads of the spatial stability. The experimental studies have been realized on a single - span members with rotation arrested at their ends, loaded by a torque applied at the mid-span. The relationship between angle of rotation of the considered cross-section and the torque has been determined. Appropriate numerical model was created in the ABAQUS program, based on the finite element method. A very good compatibility has been observed between experimental and numerical studies. The equivalent second moment of area of the uniform torsion for analysed members has been determined by comparing the experimental and analytical results to those obtained from differential equation of non-uniform torsion, based on Vlasov’s theory. Additionally, the parametric analyses of similar members subjected to the uniform torsion, for the richer range of cross-sections have been carried out by the means of SOFiSTiK program. The purpose of the latter was determining parametrical formulas for calculation of the second moment of area of uniform torsion.

scholarly journals Mechanical Assessment of Fuel Line Hoses under Variable Pressure

2019 ◽  
Vol 56 (2) ◽  
pp. 466-468
Author(s):  
Ramona Nagy ◽  
Remus Stefan Maruta ◽  
Mihai Hluscu ◽  
Karoly Menyhardt
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Automotive Industry ◽  
Production Costs ◽  
Variable Pressure ◽  
The Finite Element Method ◽  
Post Production ◽  
Element Method

The automotive industry is one of the largest consumer of flexible hoses for fluids such as fuel or cooling. In order to limit the post production costs, every aspect of a vehicle must be tested in advance, including the lifespan, durability or failure of hoses. Throughout this paper summary results are presented for 4 types of fuel line hoses tested under controlled displacement loads at various pressures in order to validate the Finite Element Method simulations.

scholarly journals Composite materials reinforced with ceramic waste and matrix of unsaturated polyester for applications in the automotive industry

DYNA ◽  
2020 ◽  
Vol 87 (212) ◽  
pp. 251-258
Author(s):  
Jorge Antonio Velasco Parra ◽  
Bladimir A. Ramón Valencia ◽  
William Javier Mora Espinosa
Keyword(s):  
Composite Materials ◽  
Automotive Industry ◽  
Ceramic Industry ◽  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Resin Matrix ◽  
The Finite Element Method ◽  
Bending Tests ◽  
Linear Behavior ◽  
Original Part

In the present investigation an alternative of recycling was evaluated for the residues derived from defective pieces of the ceramic industry, harnessing them as reinforcement in composite materials for the manufacture of parts used in the automotive sector. Sintered clay microparticles to 10% p/p were mixed in an unsaturated polyester resin matrix, through the cast molding technique. Bending tests were performed that showed an elastic-linear behavior, typical of a fragile material. The structure was analyzed through scanning electron microscopy, checking the fragile failure mechanism and a good dispersion of the microparticles. A simulation was carried out with the finite element method, for the design of a motorcycle brake lever, with results that demonstrate a better distribution of stresses and reduction in mass with respect to the original part. Finally, a prototype brake lever was manufactured using computationally validated geometry.

scholarly journals An improved shear deformation theory for bending beams with symmetrically varying mechanical properties in the depth direction

2020 ◽  
Vol 231 (10) ◽  
pp. 4381-4395 ◽  
Author(s):  
Krzysztof Magnucki ◽  
Jerzy Lewinski ◽  
Ewa Magnucka-Blandzi
Keyword(s):  
Mechanical Properties ◽  
Shear Deformation ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
The Finite Element Method ◽  
Three Point Bending ◽  
Total Potential ◽  
Depth Direction ◽  
Numerical Studies ◽  
The Individual

Abstract The paper is devoted to simply supported beams under three-point bending. Their mechanical properties symmetrically vary in the depth direction. The individual shear deformation theory for beams of such features is proposed. Based on the principle of stationary total potential energy the differential equations of equilibrium are obtained. The system of the equations is analytically solved, and the shear coefficients and deflections of example beams are calculated. The solution is compared with other analytical results obtained with the use of another deformation function. Moreover, the bending problem of these beams is also numerically studied using the finite element method. Results of analytical and numerical studies are presented in Figures and Tables.

A Study of Burr Formation Processes Using the Finite Element Method: Part I

1999 ◽  
Vol 122 (2) ◽  
pp. 221-228 ◽  
Author(s):  
I. W. Park ◽  
D. A. Dornfeld
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Metal Cutting ◽  
Ductile Failure ◽  
Development Stage ◽  
Burr Formation ◽  
The Finite Element Method ◽  
Initial Development ◽  
Final Development ◽  
Element Method

A finite element model of orthogonal metal cutting including burr formation is presented. A metal-cutting simulation procedure based on a ductile failure criterion is proposed for the purpose of better understanding the burr formation mechanism and obtaining a quantitative analysis of burrs using the finite element method. In this study, the four stages of burr formation, i.e., initiation, initial development, pivoting point, and final development stages, are investigated based on the stress and strain contours with the progressive change of geometry at the edge of the workpiece. Also, the characteristics of thick and thin burrs are clarified along with the negative deformation zone formed in front of the tool edge in the final development stage. [S0094-4289(00)00702-7]

An Efficient Design Procedure for MEMS Electrothermal Microgripper

2021 ◽  
pp. 1-6
Author(s):  
Ananya Roy ◽  
Rajasree Sarkar ◽  
Arunava Banerjee ◽  
M Nabi
Keyword(s):  
Design Parameter ◽  
Low Voltage ◽  
Design Procedure ◽  
Design Parameters ◽  
Optimized Design ◽  
Efficient Design ◽  
The Finite Element Method ◽  
Compact Size ◽  
Sine Cosine Algorithm ◽  
Parameter Values

Abstract With the development of miniaturization technology, MEMS electrothermal microgrippers have been widely used owing to their compact size, ease of manufacturing, and low production cost. Since most of these systems are governed by partial differential equations (PDEs), modeling of microgrippers poses a significant challenge for designers. To reduce the overall computational complexity, it is a common practice to model the microgripper system using the finite element method (FEM). During the design process, the geometric and analytical properties of the microgripper influence the system dynamics to a great extent, and this work focuses on studying the effects of such parameter changes. In low voltage applications, the performance of the microgripper is influenced by the geometrical variations, and the air gap. Hence, for the modeling of the microgripper, actuator arm lengths, and the gap between the arms are chosen as the two main geometric design parameters, while the input current density is considered as the analytical design parameter. In this work, the optimized design parameter values for maximum possible displacement are obtained with the use of Sine Cosine Algorithm (SCA). Further, an averaging operation is proposed for efficiently designing the MEMS electrothermal microgripper, and the efficacy of the proposed design methodology is demonstrated through simulation studies.

A Combination of Singular Cell-Based Smoothed Radial Point Interpolation Method and FEM in Solving Fracture Problem

2018 ◽  
Vol 15 (08) ◽  
pp. 1850079 ◽  
Author(s):  
Guiyong Zhang ◽  
Yaomei Wang ◽  
Yong Jiang ◽  
Yichen Jiang ◽  
Zhi Zong
Keyword(s):  
Strain Energy ◽  
Interpolation Method ◽  
The Finite Element Method ◽  
Radial Point Interpolation Method ◽  
Bound Solution ◽  
Numerical Studies ◽  
Radial Point Interpolation ◽  
Point Interpolation Method ◽  
Point Interpolation ◽  
Lower Bound Solution

The singular cell-based smoothed radial point interpolation method (CS-RPIM) has been previously proposed and shown good performance in solving fracture problems. Motivated from the fact that CS-RPIM performs over softly by providing an upper bound solution and the finite element method (FEM) is overly stiff by providing a lower bound solution, this work proposes a combination of singular CS-RPIM and FEM with a correlation coefficient [Formula: see text], and [Formula: see text] has been recommended through intensive numerical studies. Several numerical examples have been studied and the proposed method has been found perform quite well from both stress intensity factors and strain energy.

scholarly journals Catalytic constants enable the emergence of bistability in dual phosphorylation

2014 ◽  
Vol 11 (95) ◽  
pp. 20140158 ◽  
Author(s):  
Carsten Conradi ◽  
Maya Mincheva
Keyword(s):  
Total Concentration ◽  
Principal Component ◽  
Intracellular Signalling ◽  
Theoretical Studies ◽  
Direct Computation ◽  
Phosphorylation Of Proteins ◽  
Numerical Studies ◽  
Numerical Effort ◽  
Michaelis Constants ◽  
Parameter Values

Dual phosphorylation of proteins is a principal component of intracellular signalling. Bistability is considered an important property of such systems and its origin is not yet completely understood. Theoretical studies have established parameter values for multistationarity and bistability for many types of proteins. However, up to now no formal criterion linking multistationarity and bistability to the parameter values characterizing dual phosphorylation has been established. Deciding whether an unclassified protein has the capacity for bistability, therefore requires careful numerical studies. Here, we present two general algebraic conditions in the form of inequalities. The first employs the catalytic constants, and if satisfied guarantees multistationarity (and hence the potential for bistability). The second involves the catalytic and Michaelis constants, and if satisfied guarantees uniqueness of steady states (and hence absence of bistability). Our method also allows for the direct computation of the total concentration values such that multistationarity occurs. Applying our results yields insights into the emergence of bistability in the ERK–MEK–MKP system that previously required a delicate numerical effort. Our algebraic conditions present a practical way to determine the capacity for bistability and hence will be a useful tool for examining the origin of bistability in many models containing dual phosphorylation.

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