NVH Performance of Lightweight Glazing Materials in Vehicle Design

2012 ◽  
Author(s):  
Yuksel Gur ◽  
Rick Wykoff ◽  
Kenneth E. Nietering ◽  
David A. Wagner
Keyword(s):  
Fuel Economy ◽  
Weight Reduction ◽  
Loss Factor ◽  
Lightweight Design ◽  
Research Work ◽  
Damping Properties ◽  
Tempered Glass ◽  
Weight Saving ◽  
Damping Loss Factor ◽  
Vehicle Purchase

Fuel economy and NVH (noise, vibration, and harshness) performance of vehicles are important parameters in a customer’s vehicle purchase decision. Lightweight vehicle designs are necessary to help with fuel economy improvements. In this research work, the weight saving potential and NVH performance of different lightweight glazing materials are investigated to help the lightweight design effort. The lightweight glazing materials included in this study are “Material A”, “Material B”, “Material C” with regular lamination, and “Material C” with acoustic lamination. The results of this research work indicate that the lightweight glazing materials have 30% to 40% weight saving potentials without NVH penalty. These materials have much higher damping properties than conventional tempered glass so they can compensate for the mass reduction influence on vehicle NVH. The tire patch noise reduction, vehicle transparency, and wind noise results of “Vehicle A” tested with different lightweight backlight designs indicate that there is almost no acoustic response difference between the tempered glass and other lightweight alternative backlight designs. Damping loss factor measurements indicate that “Material C” with acoustic PVB (polyvinyl-butyral) has the highest damping loss factor value of 37%. The “Material C” backlight with acoustic PVB is the best among all the lightweight alternatives and brings 29% weight reduction without any NVH degradation. Statistical Energy Analysis (SEA) results also indicate that it is possible to eliminate the NVH degradation by using glazing material having high material damping properties or using laminated panels having damping loss values in the range of 6% to 20%. In this paper, we only address the weight reduction and NVH performance of light weight glazing materials but not the costs or any potential assembly procedure changes.

Damping Properties and Mechanism of 0-3 PMN/CB/EP Composites

2009 ◽  
Vol 66 ◽  
pp. 45-48 ◽  
Author(s):  
Min Xian Shi ◽  
Zhi Xiong Huang ◽  
Tao Wei ◽  
Lian Meng Zhang
Keyword(s):  
Carbon Black ◽  
Epoxy Resin ◽  
Loss Factor ◽  
Piezoelectric Ceramic ◽  
Volume Resistivity ◽  
Damping Properties ◽  
Casting Method ◽  
Conductive Carbon Black ◽  
Damping Loss Factor ◽  
Peak Value

0-3 piezoelectric ceramic PMN/conductive carbon black(CB)/epoxy resin(EP) composites were prepared by resin casting method. The electric and damping properties of PMN/CB/EP composites were detected. The volume resistivity of the composites decreases with the addition of conductive carbon black, and the composites experience transition from insulator to semiconductor when the CB content is 6% weight of the resin in the composites. Damping loss factor-temperature curves scanned by DMA showed that the peak value of damping loss factor(tanmax), the loss factor area(TA) and the damping temperature range(T) of the composites increase and reach to maximum values when CB content is 6% weight of EP resin, then drop a little with CB contents further increasing. When CB was just at threshold content 6% of epoxy weight the composite converts from insulator to semiconductor with the volume resistivity being about 108 Ωm and piezo-damping mechanism plays efficiently.

scholarly journals Vibration Damping Measurement on Car Windshields

2018 ◽  
Vol 63 (1) ◽  
pp. 1-6
Author(s):  
Balázs Vehovszky ◽  
István Horváth ◽  
Karl Slenczka ◽  
Martin Schuster ◽  
Tamás Jakubík
Keyword(s):  
Loss Factor ◽  
Laser Scanning ◽  
Measuring Method ◽  
Vibration Damping ◽  
3D Laser Scanning ◽  
Damping Properties ◽  
Reverberation Time ◽  
Damping Loss Factor ◽  
Modal Behavior

Knowledge of the damping properties of a windshield is a fundamental element of the acoustical characterization of a car. The measuring method of damping for a windshield is presented in the paper. The damping loss factor – as a basic measure of mechanical damping – was determined experimentally by two means: the reverberation time from impact hammer testing as well as the modal behavior from 3D laser scanning vibrometer measurements. The results proved that the modal shapes have a fundamental effect on the measured damping values.

Electric and Damping Properties of PU Based IPNs-BaTiO3 Nanocomposites

2007 ◽  
Vol 336-338 ◽  
pp. 118-120
Author(s):  
Dong Yan Tang ◽  
Zheng Jin ◽  
Liang Sheng Qiang
Keyword(s):  
Dielectric Properties ◽  
Loss Factor ◽  
Synergistic Effects ◽  
Electric Properties ◽  
Damping Properties ◽  
Damping Property ◽  
Frictional Damping ◽  
Damping Loss Factor ◽  
The Relationship

(PU/UP IPNs)-BaTiO3 nanocomposites with different amounts of BaTiO3 nanopowder are prepared and polarized. The ferroelectric and dielectric properties are detected and the relationship between electric properties and damping properties are discussed in detail. Results indicate that the synergistic effects can be created successfully by elastic damping of polymer, frictional damping of BaTiO3, and piezoelectric damping of nanocomposites after poling. The nanocomposites increase the damping property evidently and sustain mostly ferroelectric and dielectric characters of inorganic phase. The introduction of BaTiO3 into IPNs decreases the resistivity, and this has advantages to enlarge the damping loss factor (tanδ).

scholarly journals Modified Nanoclays/Straw Fillers as Functional Additives of Natural Rubber Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 799
Author(s):  
Justyna Miedzianowska ◽  
Marcin Masłowski ◽  
Przemysław Rybiński ◽  
Krzysztof Strzelec
Keyword(s):  
Natural Rubber ◽  
Raw Materials ◽  
Research Work ◽  
Damping Properties ◽  
Main Research ◽  
Functional Additives ◽  
Different Types ◽  
Elastomeric Materials ◽  
Research Goal ◽  
The Impact

Increasingly, raw materials of natural origin are used as fillers in polymer composites. Such biocomposites have satisfactory properties. To ensure above-average functional properties, modifications of biofillers with other materials are also used. The presented research work aimed to produce and characterize elastomeric materials with a straw-based filler and four different types of montmorillonite. The main research goal was to obtain improved functional parameters of vulcanizates based on natural rubber. A series of composites filled with straw and certain types of modified and unmodified nano-clays in various ratios and amounts were prepared. Then, they were subjected to a series of tests to assess the impact of the hybrids used on the final product. It has been shown that the addition of optimal amounts of biofillers can, inter alia, increase the tensile strength of the composite, improve damping properties, extend the burning time of the material and affect the course of vulcanization or cross-linking density.

A strengthening approach for damping property and shape memory property of acrylic rubber/polylactide blends

2018 ◽  
Vol 51 (7-8) ◽  
pp. 626-643
Author(s):  
Chengliang Li ◽  
Xingxing Ji ◽  
Yang Lyu ◽  
Xinyan Shi
Keyword(s):  
Shape Memory ◽  
Loss Factor ◽  
Phenol Formaldehyde ◽  
Mechanical Analysis ◽  
Damping Properties ◽  
Shape Memory Property ◽  
Memory Property ◽  
Damping Material ◽  
Shape Memory Properties ◽  
Shape Memory Effects

In this work, a damping material was successfully prepared by blending acrylic rubber (ACM) and polylactide (PLA) with sulfur and soap salt as the curing agents. A phenol-formaldehyde (PF) resin was used as a modifier. The effects of PF on the mechanical properties, damping properties, compatibility and shape memory properties of the blends were studied. The compatibility and damping properties were characterized by dynamic mechanical analysis, Fourier transform infrared spectroscope and microstructure analysis. The shape memory properties were examined by thermal mechanical analyser. The results revealed that the tensile strength of the blends was decreased and the toughness was increased with the increase of PF loadings. The introduction of PF improved the compatibility between PLA and ACM, which was deduced from the fact that the glass transition temperature of ACM was increased and the two loss factor peaks became closer. It was also found that the loss factor peak became higher and the effective damping temperature range became wider due to the formation of hydrogen bonding, implying that the damping properties of ACM/PLA blends were significantly improved. The ACM/PLA blends exhibited good dual-shape memory effect and its shape recovery ratio was increased by introduction of PF and raising the trigger temperature. The blends also exhibited good triple-shape memory property, which was dramatically improved by the introduction of PF. The mechanisms for the enhanced shape memory effects were then analysed.

scholarly journals Experimental study on the compressive strength, damping and interfacial transition zone properties of modified recycled aggregate concrete

2019 ◽  
Vol 6 (12) ◽  
pp. 190813
Author(s):  
Bin Lei ◽  
Huajian Liu ◽  
Zhimin Yao ◽  
Zhuo Tang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Transition Zone ◽  
Loss Factor ◽  
Steel Fibre ◽  
Interfacial Transition Zone ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Damping Properties ◽  
Aggregate Concrete

At present, many modification methods have been proposed to improve the performance of recycled aggregate concrete (RAC). In this study, tests on the compressive strength and damping properties of modified RAC with the addition of different proportions of recycled coarse aggregate (RCA) (0, 50, 100%), rubber powder (10, 15, 20%), steel fibre (5, 7.5, 10%) and fly ash (15, 20, 5%) are carried out. To elucidate the effect of the modification method on the interfacial transition zone (ITZ) performance of RAC, model ITZ specimens are used for push-out tests. The results show that when the replacement rate of RCA reaches 100%, the loss factor of the RAC is 6.0% higher than that of natural aggregate concrete; however, the compressive strength of the RAC decreases by 22.6%. With the addition of 20% rubber powder, the damping capacity of the modified RAC increases by 213.7%, while the compressive strength of the modified RAC decreases by 47.5%. However, with the addition of steel fibre and fly ash, both the compressive strength and loss factor of the RAC specimens increase. With a steel fibre content of 10 wt%, the compressive strength and loss factor of the RAC increase by 21.9% and 15.2%, respectively. With a fly ash content of 25 wt%, the compressive strength and loss factor of the RAC increase by 8.6% and 6.9%, respectively. This demonstrates that steel fibre and fly ash are effective in improving both the damping properties and compressive strength of RAC, and steel fibre is more effective than fly ash. Two methods were used for modification of the RAC: reinforcing the RCA through impregnation with a 0.5% polyvinyl alcohol (PVA) emulsion and nano-SiO 2 solution, and strengthening the RAC integrally through the addition of fly ash as an admixture. Both of these techniques can improve the ITZ bond strength between the RAC and new mortar. Replacing 10% of the cement with fly ash in the new mortar is shown to be the best method to improve the ITZ strength.

A New Methodology for the Accurate and Consistent Identification of Modal Parameters Using Multi-FRF Analysis

1995 ◽  
Author(s):  
R. M. Lin ◽  
S.-F. Ling
Keyword(s):  
Eigenvalue Problem ◽  
Loss Factor ◽  
Frequency Response Function ◽  
Natural Frequencies ◽  
Identification Problem ◽  
Modal Parameters ◽  
Frequency Range ◽  
Case Examples ◽  
Measured Frequency Response ◽  
Damping Loss Factor

Abstract A new method for the estimation of modal parameters is presented in this paper. Unlike the majority of the existing methods which involve complicated curve fitting and interpolative procedures, the proposed method calculates the modal parameters by solving eigenvalue problem of an equivalent eigensystem derived from measured frequency response function (FRF) data. It is developed based on the practical assumption that only one incomplete column of the FRF matrix of the test structure has been measured in a frequency range of interest. All the measured FRFs are used simultaneously to construct the equivalent eigensystem matrices from which natural frequencies, damping loss factor and modeshape vectors of interest can be directly solved. Since the identification problem is reduced to an eigenvalue problem of an equivalent system, natural frequencies and damping loss factors identified are consistent. Further procedures for normalizing the identified eigenvectors so that they become mass-normalized are developed. Numerical case examples are given to demonstrate the practicality of the proposed method and results obtained are indeed very promising. It is believed that with the availability of such identification method, modal analysts’ dream of intelligent and full automatic modal analysis will become a reality.

Optimal design of differential mount using nature-inspired optimization methods

2021 ◽  
Vol 63 (8) ◽  
pp. 764-769
Author(s):  
Emre İsa Albak ◽  
Erol Solmaz ◽  
Ferruh Öztürk
Keyword(s):  
Optimum Design ◽  
Weight Reduction ◽  
Lightweight Design ◽  
Reduction Process ◽  
Optimization Methods ◽  
Convergence Speed ◽  
Structural Performance ◽  
Grey Wolf Optimizer ◽  
Solution Quality ◽  
Dragonfly Algorithm

Abstract Structural performance and lightweight design are a significant challenge in the automotive industry. Optimization methods are essential tools to overcome this challenge. Recently, nature-inspired optimization methods have been widely used to find optimum design variables for the weight reduction process. The objective of this study is to investigate the best differential mount design using nature-based optimum design techniques for weight reduction. The performances of the nature-based algorithms are tested using convergence speed, solution quality, and robustness to find the best design outlines. In order to examine the structural performance of the differential mount, static analyses are performed using the finite element method. In the first step of the optimization study, a sampling space is generated by the Latin hypercube sampling method. Then the radial basis function metamodeling technique is used to create the surrogate models. Finally, differential mount optimization is performed by using genetic algorithms (GA), particle swarm optimization (PSO), grey wolf optimizer (GWO), moth-flame optimization (MFO), ant lion optimizer (ALO) and dragonfly algorithm (DA), and the results are compared. All methods except PSO gave good and close results. Considering solution quality, robustness and convergence speed data, the best optimization methods were found to be MFO and ALO. As a result of the optimization, the differential mount weight is reduced by 14.6 wt.-% compared to the initial design.

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