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Academic literature on the topic 'NVH tests'

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Published: 1 June 2024

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Journal articles on the topic "NVH tests"

Chakroun, Ala Eddin, Mattia Battarra, and Emiliano Mucchi. "Influence of the Hydraulic Circuit Setup on the Dynamic Performance of an Axial Piston Pump by Numerical and Experimental Analysis." Mathematical Problems in Engineering 2024 (April 18, 2024): 1–16. http://dx.doi.org/10.1155/2024/2966138.

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The hydraulic circuit in hydraulic mechanisms may be the cause of several vibration anomalies. Flexible pipes, in particular, commonly used in test rigs, may be the source of vibration issues due to their relatively low natural frequencies altering the pump noise, vibration, and harshness (NVH) performance. The purpose of this study is to detail a methodology based on lumped parameter modeling and experiments to analyze the circuit NVH behavior. An experimental study is carried out on two pump designs to determine the outlet pressure fluctuation of various test rig configurations. Numerical simulations are also performed to simulate the actual behavior of the hydraulic system considering these different test configurations. The tests are carried out at a chosen frequency range with a hydraulic circuit configuration representing realistic layouts. In these situations, the hydraulic circuit layout can be the source of NVH anomalies. Realistic design solutions are proposed to modify the test rig NVH behavior in order to achieve a flat response throughout the desired working range.

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Singh, Rahul, Amogh Nalawade, Manish Pande, and Punit Singh. "Vibration and noise characteristics of an inverter for electric vehicle application." Vibroengineering Procedia 50 (September 21, 2023): 145–51. http://dx.doi.org/10.21595/vp.2023.23563.

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Noise, Vibration & Harshness (NVH) is one of the key parameters associated with comfort of an automobile. An Electric Vehicle (EV) consists of transmission driven by electric motor which ultimately gets its power or current supply from inverter. As per Electric vehicle architecture, motor ranks first followed by transmission and inverter in terms of NVH performance. The function of an inverter is to convert DC current from battery source to 3-phase AC current which goes to electric motor. Torque and speed characteristics of motor is dependent on current and voltage supply from inverter. Hence it is important to assess NVH characteristics of inverter as well. In this paper, vibration and acoustic performance of a standalone EV inverter have been studied by testing it at different vehicle operating conditions. Ideally the output 3 phase AC current from inverter should contain only electrical frequency, but it is observed that AC current contains harmonics in the form of linear combination of electrical frequency and switching frequency. From this study, observations from NVH tests on an EV inverter is highlighted in frequency range where relatively high vibration and noise levels were present.

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Schweighardt, A., B. Vehovszky, and D. Feszty. "The effect of the preload determination process on dynamic mechanical properties." Journal of Physics: Conference Series 2677, no. 1 (December 1, 2023): 012007. http://dx.doi.org/10.1088/1742-6596/2677/1/012007.

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Abstract NVH simulation and experimental methods are getting more and more important because of the increased customer needs for reliability and comfort. In order to obtain appropriate NVH simulation results accurate material properties have to be provided as input parameters. In case of the dynamic mechanical property determination of acoustic viscoelastic foams the results may vary greatly depending on the measurement settings and the quality of the measurement. This study evaluates the effect of the preload determination process on dynamic mechanical properties and the repeatability of the dynamic compression tests. Finally, conclusions are drawn and suggestions are made for the settings.

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Guinebretière, Marie-Hélène, Sandrine Auger, Nathalie Galleron, Matthias Contzen, Benoit De Sarrau, Marie-Laure De Buyser, Gilles Lamberet, et al. "Bacillus cytotoxicus sp. nov. is a novel thermotolerant species of the Bacillus cereus Group occasionally associated with food poisoning." International Journal of Systematic and Evolutionary Microbiology 63, Pt_1 (January 1, 2013): 31–40. http://dx.doi.org/10.1099/ijs.0.030627-0.

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An aerobic endospore-forming bacillus (NVH 391-98T) was isolated during a severe food poisoning outbreak in France in 1998, and four other similar strains have since been isolated, also mostly from food poisoning cases. Based on 16S rRNA gene sequence similarity, these strains were shown to belong to the Bacillus cereus Group (over 97 % similarity with the current Group species) and phylogenetic distance from other validly described species of the genus Bacillus was less than 95 %. Based on 16S rRNA gene sequence similarity and MLST data, these novel strains were shown to form a robust and well-separated cluster in the B. cereus Group, and constituted the most distant cluster from species of this Group. Major fatty acids (iso-C15 : 0, C16 : 0, iso-C17 : 0, anteiso-C15 : 0, iso-C16 : 0, iso-C13 : 0) supported the affiliation of these strains to the genus Bacillus , and more specifically to the B. cereus Group. NVH 391-98T taxon was more specifically characterized by an abundance of iso-C15 : 0 and low amounts of iso-C13 : 0 compared with other members of the B. cereus Group. Genome similarity together with DNA–DNA hybridization values and physiological and biochemical tests made it possible to genotypically and phenotypically differentiate NVH 391-98T taxon from the six current B. cereus Group species. NVH 391-98T therefore represents a novel species, for which the name Bacillus cytotoxicus sp. nov. is proposed, with the type strain NVH 391-98T ( = DSM 22905T = CIP 110041T).

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Dziechciarz, Arkadiusz, Aron Popp, Claudia Marțiș, and Maciej Sułowicz. "Analysis of NVH Behavior of Synchronous Reluctance Machine for EV Applications." Energies 15, no. 8 (April 11, 2022): 2785. http://dx.doi.org/10.3390/en15082785.

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In this paper, an analysis of noise and vibration of a synchronous reluctance machine for EV applications is performed. The analyzed machine was designed for electric vehicle application. The noise and vibration of a synchronous reluctance machine were first estimated during simulations; next, the obtained results were validated during laboratory tests. The analyzed model of the machine was simplified and included only stator core as it was assumed to be the main source of the machine vibration and generated noise. To simulate the noise and vibration of the machine, multiphysics modeling of the machine was performed. Laboratory tests proved the correctness of performed simulations. The obtained results allowed us to investigate the influence of the machine’s operating point on the generated noise and vibration. The frequency of the magnetic radial forces were proven to be the dominant factor in noise generation. The influence of the load and current angle on the machine’s noise and vibration was proven to be negligible. It was also proven that considering only the stator structure in numerical analysis of the noise and vibration of the machine leads to valuable results.

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Guo, Han, Jianwu Zhang, and Haisheng Yu. "Robust optimisation of dynamic and NVH characteristics for compound power-split hybrid transmission." Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 233, no. 4 (June 25, 2019): 817–26. http://dx.doi.org/10.1177/1464419319856774.

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In this paper, vibro-acoustic characteristics of a power-split hybrid transmission including a compound planetary gear set are investigated by numerical procedure and refined system dynamics modelling. For validation of the numerical predictions, bench tests are performed for dynamic and acoustic responses of the hybrid transmission, contribution rates of acoustic radiation power induced due to the planetary gears, support bearings, transmission shafts and the gearbox housing are estimated. In improving the noise, vibration and harshness (NVH) performance of the transmission during hybrid vehicle acceleration, traction torques of the motors against the planetary gear parametric resonance are formulated and an optimal control strategy is proposed. By real road NVH test results acquired on board of the midsize hybrid car, it is demonstrated that a significant reduction of the planetary gear whine noise is achieved. As a result, numerical approaches applied to establish relationships between torques of the two traction motors and parametric excitations of the compound planetary gear train are experimentally validated.

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Li, Hui Bin, Awais A.M., Qi Chen Lu, and De Quan Jin. "Experimental Study on Durability and NVH of Rear Driving Axle of Minibus." Advanced Materials Research 655-657 (January 2013): 511–14. http://dx.doi.org/10.4028/www.scientific.net/amr.655-657.511.

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Experiments on the durability for the rear driving axle were conducted in bench tests. By using time domain and frequency domain methods, the vibration and noise signals at bearings of driving axle were sampled and then analyzed. On the one hand, we find that the vibration level and noise level change with the wear of gears and bearings. On the other hand, with the development of the wear of gear and bearings, the frequency components of vibration and noise change with time. These experimental results will give help to further study of the durability and NVH characteristic of the rear driving axle.

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Shi, Hui, Wenku Shi, Liang Sun, and Zhiyong Chen. "Improving Camper Comfort by Optimizing the Vibration Isolation of Air-Conditioning Compressor." Mathematical Problems in Engineering 2020 (December 23, 2020): 1–14. http://dx.doi.org/10.1155/2020/2958604.

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Compressors are the main excitation source of vibration and noise in camper air-conditioning systems, which directly affects the NVH characteristics in campers. The vibration and noise reduction for camper comfort improvement can be implemented by the optimization method. This paper presents vibration and noise improvement in camper by systematically optimizing the vibration isolation performance of air-conditioning compressor. To analyze the compressor vibration characteristics, operational vibration tests under different conditions and modal identification are implemented. Based on the analysis results, a genetic algorithm is used to optimize the stiffness of the compressor vibration isolation element by the energy decoupling method (EDM). The stiffness, natural frequencies, and energy decoupling rate (EDR) of the compressor vibration isolation system (CVIS) are compared between preoptimization and postoptimization. The stiffness and strength characteristics of the optimized isolation system are verified by the finite element method. Operational vibration and noise tests of a camper are performed to validate the optimization effect. The improvement of camper comfort demonstrates that the proposed optimization procedure of CVIS is effective.

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Yong, Sukjun, and JangSeok Park. "A study on the new PET composite sound-absorbing material applicable to automotive interior materials." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, no. 4 (February 1, 2023): 3297–302. http://dx.doi.org/10.3397/in_2022_0466.

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Various types of sound-absorbing materials are used in vehicles according to external noise and conditions. As sound-absorbing materials for automobiles, there are fiber-type materials such as PET fiber or glass fiber, and foam-type materials such as polyurethane. Among them, PET fiber materials have excellent advantages in terms of weight reduction and recycling, but urethane foam is applied due to their low NVH performance and compressive stress. Recently, as interest in eco-friendly vehicles increases, development of sound absorbing materials using PET fiber is required. To improve this problem, in this study, research was conducted on improving sound absorption performance and compression performance by changing the composition ratio of PET fibers constituting the sound absorption material. The acoustic properties were measured by ALPHA-CABIN and BUCK tests

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Kyprianou, A., J. Giacomin, K. Worden, M. Heidrich, and J. Bocking. "Differential evolution based identification of automotive hydraulic engine mount model parameters." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 214, no. 3 (March 1, 2000): 249–64. http://dx.doi.org/10.1243/0954407001527402.

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Hydraulic engine mounts are commonly used in automotive applications, and numerical models exist for performing full-vehicle noise, vibration and harshness (NVH) studies by means of multibody simulation. The parameters of these models are usually determined by the manufacturer from first-principle numerical calculations, or by means of direct testing of the individual components. This paper describes, instead, a four-step identification method developed to determine the parameter values of a specific hydromount numerical model, the Freudenberg hydromount equations, a set of highly non-linear piecewise-continuous differential equations. The identification procedure is based on two concepts, the first being the use of the differential evolution algorithm for determining optimal parameter values, while the second is the use of data obtained from a series of experimental tests of progressively higher displacement amplitude. Identified parameters provide models whose mean square errors between the calculated output force time history and the experimentally measured force time history are typically of the order of 1-2 per cent.

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Dissertations / Theses on the topic "NVH tests"

De, la Cruz Miguel. "The influence of transient thermo-elastohydrodynamic conjunctions on automotive transmission rattle." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8042.

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Automotive transmission rattle is the noise generated due to impacts between manual transmissions meshing gear teeth in the presence of backlash. It is considered to be a Noise, Vibration and Harshness (NVH) phenomenon and is originated due to combustion irregularities (engine order vibrations), especially in diesel vehicles. This thesis focuses in the case of creep rattle for the MMT6 Ford Getrag transmission (six speeds plus reverse) with a DW10b, 4-cylinder, 4-stroke, 2.0 litres diesel engine. This particular rattle condition is fundamentally similar to any other where an engaged gear is pertained (drive, over-run or float), with the 1st or 2nd gear engaged at a very low engine speed. The numerical models include an initial single degree of freedom (DoF) simulation. It comprises either of the engaged gear pair under Hertzian contact conditions or of a loose gear pair under hydrodynamic regime of lubrication. Once the validity of this model is established and correlated with the results obtained from a single gear pair test rig, simulations of increasing complexity can be envisaged. A 7 DoF numerical model is, therefore, developed. The Hertzian contact model still prevails for the engaged gear pair, whereas an analytical hydrodynamic solution is implemented for the remaining 6 loose gear wheels and Petrov s law is applied to the needle bearings retaining the gear wheels. With the aim of accommodating a fully lubricated model of all the tribological conjunctions, an analytical elastohydrodynamic (EHL) Grubin type algorithm is employed. Also, the energy equation is analytically solved for hydrodynamic and elastohydrodynamic conjunctions, based on the assumptions dictated by the Peclet number. Therefore, under hydrodynamic conditions, the energy equation is governed by viscous heating and convective cooling, whereas in the EHL conjunctions the governing terms are viscous and compressive heating, together with conductive cooling. The retaining needle bearings follow the same heat generation mechanism as journal bearings. The effective viscosity, as obtained from the Houpert s equation accounting for pressure and thermal effects, is fundamental for the study of the friction in the contact. The hydrodynamic contacts are only governed by viscous friction, whereas EHL conjunctions exhibit asperity iv interactions as well as viscous effects. The results obtained from this new 7 DoF model are then compared to the experimental measurements taken from the vehicle tests and various purpose-built drivetrain rigs. A metric named Impulsion Ratio is hereby introduced, aiming to shed some light into the predictions obtained by the various models presented. This metric is the ratio of driving over resistive forces acting on each individual gear wheel. Its use is tested to predict single or double-sided rattle scenarios and, therefore, ascertaining higher and lower rattle levels. The 13 DoF model from which these conclusions were obtained includes shafts planar translation and rocking moments. The rolling element bearings supporting the shafts are, therefore, modelled to capture the inherent frequencies arising from their motion. The final model introduces the effects of transient thermo-elastohydrodynamics. This 7 DoF dynamic model accounts for a numerical solution of Reynolds equation with Elrod s cavitation algorithm for simultaneous teeth in mesh. The results obtained validate the previously used Grubin assumption by comparing the predicted central film thickness along the full mesh of one tooth. Also, the effect of starved input conditions and thermal and isothermal solutions are studied.

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Cantalogo, Alexsander. "Modelagem de \'Deadeners\' usando NASTRAN e correlação experimental." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-13032012-085537/.

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Este trabalho visa o desenvolvimento de um modelo em elementos finitos de elementos de dissipação vibratória de base betuminosa, chamados comumente de deadeners. O modelo baseia-se no algoritmo comercial MSC/NASTRAN e é correlacionado e verificado com base em dados experimentais de laboratório. O resultado final deste projeto é um modelo para os deadeners que pode ser utilizado em modelos de elementos finitos de veículos completos, facilitando assim a definição da melhor localização dos mesmos no veículo bem como a otimização de seu uso. O modelo tem melhor resultado em termos de amplitude para frequências abaixo de 200Hz, porém apresenta tendências de superestimar o efeito do amortecimento nos picos de ressonância
This project aims the development of a finite element model of vibration dissipating elements of bituminous base, commonly called \"deadeners. The proposed model is based on the finite element commercial algorithm MSC/NASTRAN and is correlated and verified on experimental data from laboratory. The end result of this project is a model for \"deadeners\" which can be used in finite element models of complete vehicles, thus facilitating better definition of their location in the vehicle as well as the optimization of its use. The model has a better result in terms of amplitude for frequencies below 200 Hz, but shows a tendency to overestimate the effects of damping at the resonance peaks

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Souza, Fernando José Pires de [UNESP]. "Eficácia de uma vacina comercial contra a raiva frente a desafios com amostras de vírus de campo comparados ao desafio padrão no teste NIH." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/94645.

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No Brasil, a potência das vacinas veterinárias contra a raiva é avaliada pelo teste NIH (“National Institutes of Health”), no qual o desempenho de uma vacina, medido pela DE50 em camundongos, é comparado ao desempenho de uma vacina de referência. São consideradas aprovadas as partidas com potência igual ou superior a 1,0 UI. O presente estudo comparou o desafio viral com vírus fixo CVS, utilizado como padrão no teste de potência NIH, a desafios com três amostras virais isoladas de bovinos naturalmente infectados. O objetivo foi verificar se as amostras de vírus de campo apresentariam virulência maior que a do CVS, o que poderia sugerir a inadequação do teste NIH para a avaliação das vacinas contra a raiva e, portanto, inferir que as vacinas aprovadas por esse teste poderiam não proteger suficientemente o rebanho. Apesar da grande variabilidade que o teste NIH pode apresentar, as três repetições desafiadas com CVS apresentaram semelhança em um intervalo de confiança de 95%, e nos desafios realizados com três amostras de vírus de campo a vacina utilizada protegeu mais do que nos desafios com CVS. Conclui-se que a virulência das amostras de vírus de campo utilizadas não foi maior que a virulência do CVS, em camundongos, e que o rigor do desafio padrão mostrou-se adequado para a avaliação da potência pelo teste NIH e, portanto, para o controle da qualidade de vacinas contra a raiva.
The potency of veterinary rabies vaccines in Brazil is evaluated by the NIH (National Institutes of Health) potency test, in which the ability of a vaccine to induce protection in mice (ED50) is compared with a reference vaccine. The batches are approved when the potency is equal or superior to 1.0 IU. The present study compared CVS strain challenges (standard strain for the potency test) with challenges that used three wild isolates of natural occurrence in cattle. The aim was to verify if the wild strains could be more virulent than the CVS. If this occurred, the NIH potency test would prove inadequate to evaluate rabies vaccines. Therefore, one could infer that the approved vaccines might not provide sufficient herd protection. Despite the great variability of NIH test, all three repetitions that were challenged with CVS were similar at a 95% confidence-level; and when challenged with wild strains, the vaccine provided better protection than the one achieved at CVS challenge. In conclusion, wild strains virulence was not greater than CVS virulence in mice. The strictness of standard challenge proved to be adequate for potency evaluation by NIH test, and consequently, for the quality control evaluation of rabies vaccines.

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Park, Hyungjoo. "Development of a Test System to Measure Squeak Propensity of Vehicle Underbody Components." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1592135515122287.

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Xie, Yuan. "Investigation on Road Noise Transmission through Steering System." Thesis, KTH, MWL Marcus Wallenberg Laboratoriet, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-224153.

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An investigation on noise transmission through the steering gear system is focused on the area of vehicle NVH (Noise Vibration and Harshness). From previous investigations it is well known that noise transmission through the steering system sometimes has a significant influence referring to tire road noise. In these cases, the interface force between steering gear and vehicle subframe is usually of interest during early stages of vehicle development. The target of the current work is to validate an approach based on a method, commonly known as the “Blocked force method” for noise and vibration testing, and check if it is possible to estimate the interface forces based on this method. This method became popular for mechanical testing in the middle 1900s [1] [2] [3], because of its easy applicability. The basic idea is to fix the component on a rigid plate and measure the interface force at the coupling points with force transducers inserted in between. It has a considerable potential in practical use, because if the blocked force could provide a good estimation for the interface force in noise transmission, it enables an efficient measurement of critical NVH behaviors without having to resort to the complete vehicle.However intuitively, the blocked force data could not be used directly. As a result, a coupled system equation is used for the coupling of the steering gear and the car body. Both the inertance of car body and steering system are taken into account, and thus introduces a compensation for the difference between vehicle and test bench. The method is validated against the transfer function measured on the full vehicle as the reference and compare this with the result calculated with the measured “Blocked force” data. Siemens Test.Lab is used for data acquisition and first data processing. Matlab is used for data post processing. Matrix symmetrization and singular value truncation is used to deal with the ill-conditioned data of steering gear inertance. A hybrid model with Finite Element data is proposed. Two test conditions are investigated: one set is with rigid coupling and the other is decoupled with rubber.

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FERRARIS, ALESSANDRO. "Automotive composite components design and test: a vibration reduction oriented approach." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2674339.

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Vehicle manufacturers initially relied on horsepower and speed performances as “standout qualities” to sell their products, but as time progressed, it became increasingly clear that customers were very much concerned about their comfort and safety while driving vehicles. In the late seventies, requirements for driver and passenger comfort were increased significantly, since-then, a large amount of effort has been invested into the vehicle improvement of noise and vibration reduction nevertheless enhancing the safety. Nowadays NVH performance is considered as a critical factor in the purchase decisions of many buyers. This work focusses on the development of a composite automotive door but, the methodology and materials applied could be extended for other panels, as there are several kinds in a typical vehicle whatever class or purpose it has. In the last years, furthermore, lightweight design imposed different design methodologies and materials like fiber reinforced plastics are becoming more and more used in the construction of vehicles for structural and non-structural parts. Reinforced plastics could perform higher performance and higher tailorable possibilities compared to conventional metallic materials, more and more composites are targeted toward structural applications involving combined dynamic, mechanical, thermal and hygral loading. Composite materials are principally preferred in such applications because of their advanced elastic properties and tailoring capability to individual design requirements. They also have the potential for incorporating significant and tailorable passive damping into the candidate structure. At the beginning, tests on two different viscoelastic materials are performed in order to identify mechanical characteristics necessary to provide valid data for numerical analysis of structures. ‘Oberst Beam Method’ is the standard test method for measuring dynamic properties of materials (ASTM E756 – 05). Mechanical characteristics of damping materials have been determined for different temperatures (SAE J1637), frequencies and at different stage of aging (ISO 60068). Besides, low-velocity impact tests have been executed (ASTM 7136). After having post-processed the experimental data, the best material has been chosen. For each test, for each material and specimens topology a significant number of specimen has been tested for statistical purpose. ASTM 756 tests have been replicated virtually and to compare the results FRF Receptance, eigenfrequencies have been matched. Excellent correlation between simulation and experiment has been found. To evaluate the FEM virtual capabilities to reproduce and simulate the dynamic response of a real component and to validate correlation methodology, a first modal analysis has been carried out on a real automotive component. An innovative composite leaf spring is subjected to a free-free frequency response test, in which a series of accelerometers measures the response of the component to an excitation imposed by an electromechanical shaker. Moreover, LIPEZ methodology permitted to post-process data logged and to evaluate the characteristic vibrating modes of the structure. While the real component has been experimentally tested, FEM numerical simulation is reproduced. In the end, eigenfrequencies, eigenmodes (MAC) of experimental and virtual tests have been compared; excellent mode shape correlation has been found-out, errors on eigenfrequencies lower than 5%. Last part of this dissertation is focussed on the design, testing, and development of a damped door by means of interlaminar materials. The activity has been performed in two stages: undamped door testing and correlation with FEM and then manufacturing, testing and correlation of the damped solution. LIPEZ modal extraction algorithm has been used to extract modal parameters for the two artifacts, as well. The undamped door has been tested, real and virtual receptance, eigenfrequencies, eigenmodes computed and correlated. Damped material patches have been dimensioned and positioned considering a trade-off between added mass, costs and vibro-reduction capabilities. Modal analysis executed on the door have demonstrated that high damping capabilities have been achieved with limited drawbacks on weight increase (+5%) and inappreciable cost augmentation. In view of the scopes of the work, the results are deemed satisfactory.

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Otipka, Václav. "Konstrukční návrh zkušebního stavu s uzavřenou smyčkou toku momentu pro experimentální ověření parametrů převodových ústrojí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-378013.

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The thesis deals with the design of the experimental testing rig. Test rig is designed to measure NVH transmission parameters. First, basic knowledge of vibro-acoustic measurement is discussed. This is followed by an evaluation of the most commonly used power devices to derive real loads on measured gearboxes. In more detail, a back-to-back test rig is disassembled among other things. In the thesis are described two main components, which are composed of a connecting element and a test bench. Both components were optimized during the design due to their modal properties. Numerical modal analysis was performed in ANSYS Workbench software. The thesis also includes strength calculations performed using both numerical and analytical approaches. The indispensable result of the design work is the complete drawing documentation. Finally, measurements of vibrations and noise on the physically made connecting element assembly have been performed and subsequently evaluated.

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Baker, Erin R. "Attitudes and Practices of NIH-funded Researchers Toward Reporting Individual Test Results to Research Subjects." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1147100909.

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Schille, Fabian Martin [Verfasser], and A. [Akademischer Betreuer] Albers. "Methode zur generationsübergreifenden NVH-Optimierung des Wiederstartkomforts von Hybridfahrzeugen durch eine manöverbasierte Validierung auf dem Akustikrollenprüfstand = Method for an intergenerational NVH-optimisation regarding the restarting comfort of hybrid vehicles using a manoeuvre-based validation on the acoustic roller test bench / Fabian Martin Schille ; Betreuer: A. Albers." Karlsruhe : KIT-Bibliothek, 2021. http://d-nb.info/1235072436/34.

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Virhammar, Johan. "Idiopathic Normal Pressure Hydrocephalus : Cerebrospinal Fluid Tap Test and Magnetic Resonance Imaging as Preoperative Prognostic Investigations." Doctoral thesis, Uppsala universitet, Neurologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-222779.

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Idiopathic normal pressure hydrocephalus (iNPH) is a condition with dilated cerebral ventricles but intracranial pressure within normal limits. The symptoms of gait impairment, cognitive decline and urinary incontinence develop gradually. Treatment with shunt insertion results in improvement in eight out of ten patients. The cerebrospinal fluid tap test (CSF TT) and preoperative magnetic resonance imaging (MRI) are methods used to select patients who may benefit from shunt surgery, but they are performed and interpreted differently in different centers throughout the world. The aim of this thesis was to evaluate the performance of the CSF TT and the underlying mechanisms of improvement in gait function after CSF removal, and to investigate the prognostic value of preoperative MRI scans. Improvement in gait and changes in cerebral blood flow (CBF) after a CSF TT were investigated in two prospective studies that included 39 and 20 patients, respectively. Gait assessment and perfusion MRI were done before and several times during the first 24 hours after a CSF TT. Perfusion was investigated with pseudo-continuous arterial spin labeling. At the group level, gait function was significantly improved at all investigation times, but only one-third of individual CSF TT responders were improved at all investigation times. In patients with increased CBF in lateral and frontal white matter after the CSF TT, gait function improved more than it did in patients with decreased CBF in these regions. However, in the whole sample, there was no significant increase in CBF after CSF removal. Preoperative MRI scans were retrospectively evaluated in 109 patients with iNPH who had undergone shunt surgery. The callosal angle was smaller in shunt responders compared with non-responders. The following findings showed the highest association with a positive outcome after shunting: a small callosal angle, wide temporal horns, and occurrence of disproportionally enlarged subarachnoid space hydrocephalus. In conclusion, CBF in white matter close to the lateral ventricles may play a role in the reversibility of symptoms after CSF removal in patients with iNPH. The CSF TT should be reevaluated if the patient does not initially improve, and preoperative MRI investigations can add prognostic information regarding the selection of shunt candidates.

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Books on the topic "NVH tests"

Rudman, Jack. NVB, National Veterinary Boards. Syosset, N.Y: National Learning Corporation, 1991.

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NIH stroke scale. Bethesda, Md.?]: National Institute of Neurological Disorders and Stroke, Dept. of Health and Human Services, USA, 2011.

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Rudman, Jack. NVB, National Veterinary Boards: Administered by the National Board of Veterinary Medical Examiners (NBVME) of the American Veterinary Medical Association (AVMA). Syosset, N.Y: National Learning Corp., 1990.

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1945-, Moon Bob, Murphy Patricia 1952-, and Open University, eds. Developments in learning and assessment. London: Hodder & Stoughton in association with the Open University, 1989.

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Kaplan, Tamara, and Tracey Milligan. Dementia 2: CJD, NPH, and Summary (DRAFT). Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190650261.003.0010.

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The video in this chapter explores dementia, and focuses on Creutzfeldt Jakob Disease (CJD), and Normal Pressure Hydrocephalus (NPH). It outlines the causes and symptoms of CJD, as well as diagnostic tests (MRI, CSF presence of protein 14-3-3, EEG, and biopsy). It also discusses NPH, including its characteristics and treatment.

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Standard Variety Pack 2 Contains 3 Tests Maths 11b Vr 11b Nvr 11b. GL Assessment, 2003.

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Kabaaru moy̳y̳o o no Macca winndiri d̳um nih: Feccere adannde e linjiila ... Dakar, Sénégal: M.E.A.O, 1995.

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International Conference on Gears 2017. VDI Verlag, 2017. http://dx.doi.org/10.51202/9783181022948.

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Talking about the design of modern high-performance power train applications, one of the essential components to focus on are the gears. Gears convert torque and speed in a very wide power range, at low cost and with minimal losses and noise emission. However, the demands regarding cost, power density, NVH-behavior and efficiency are steadily increasing. Demands, which can only be met using modern gearing technologies that allow combining individual materials, heat treatment and manufacturing processes. Particularly in the industrial sector, the requirements for the reliability and service life of the gear units have increased. Therefore, more and more accurate calculation methods are required for the load bearing capacity, life expectancy and failure probability as well as better test methods. This aspect is also becoming more important with regard to Industry 4.0 and Predictive Maintenance. In addition, the potentials of innovative production methods like powder metal sintering, plas...

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Murphy, Patricia, and Bob Moon. Developments in Learning and Assessment. Hodder Arnold H&S, 1990.

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Book chapters on the topic "NVH tests"

Millitzer, Jonathan, Jan Hansmann, Giovanni Lapiccirella, Christoph Tamm, and Sven Herold. "Tuning and Emulation of Mechanical Characteristics – Tunable Mounts and a Mechanical Hardware-in-the-Loop Approach for More Efficient Research and Testing." In Lecture Notes in Mechanical Engineering, 129–44. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-77256-7_12.

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AbstractNumerical simulations offer a wide range of benefits, therefore they are widely used in research and development. One of the biggest benefits is the possibility of automated parameter variation. This allow testing different scenarios in a very short period of time. Nevertheless, physical experiments in the laboratory or on a test rig are still necessary and will still be necessary in the future. The physical experiments offer benefits e.g. for very complex and/or nonlinear systems and are needed for the validation of numerical models.Fraunhofer LBF has developed hardware solutions to bring the benefit of rapid and automated parameter variation to experimental environments. These solutions allow the tuning and emulation of the mechanical properties, like stiffness, damping and eigenfrequencies of structures.The work presents two approaches: First a stiffness tunable mount, which has been used in laboratory tests in the field of semi-active load path redistribution. It allowed the researcher to test the semi-active system under different mechanical boundary conditions in a short period of time. Second, a mechanical Hardware-in-the-loop (mHIL) approach for the NVH development of vehicles components is presented. Here a mHIL-system is used to emulate the mechanical characteristics of a vehicle’s body in white in a wide frequency range. This allows the experimental NVH optimization of vehicle components under realistic boundary conditions, without actually needing a (prototype) body in white.

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Chen, Yong. "NVH Test and Optimization for New Energy Vehicle Powertrain." In New Energy Vehicle Powertrain Technologies and Applications, 251–382. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-9566-8_5.

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Yang, Jin, Jun Lan, Xu YongJiang, Jin Cai, XiaoNan Zhang, HanJie Liu, and YanLin Shi. "The Application of Doppler Laser Vibrometer in the Engine NVH Dynocell Test." In Lecture Notes in Electrical Engineering, 607–17. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-33832-8_48.

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Gur, Yuksel, Jian Pan, and David A. Wagner. "Low- and high-frequency NVH CAE – test methods for development of a lightweight sedan design." In Proceedings, 21–41. Wiesbaden: Springer Fachmedien Wiesbaden, 2019. http://dx.doi.org/10.1007/978-3-658-20251-4_2.

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Jamet, Quentin, Etienne Mémin, Franck Dumas, Long Li, and Pierre Garreau. "Toward a Stochastic Parameterization for Oceanic Deep Convection." In Mathematics of Planet Earth, 143–57. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-40094-0_6.

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AbstractCurrent climate models are known to systematically overestimate the rate of deep water formation at high latitudes in response to too deep and too frequent deep convection events. We propose in this study to investigate a misrepresentation of deep convection in Hydrostatic Primitive Equation (HPE) ocean and climate models due to the lack of constraints on vertical dynamics. We discuss the potential of the Location Uncertainty (LU) stochastic representation of geophysical flow dynamics to help in the process of re-introducing some degree of non-hydrostatic physics in HPE models through a pressure correction method. We then test our ideas with idealized Large Eddy Simulations (LES) of buoyancy driven free convection with the CROCO modeling platform. Preliminary results at LES resolution exhibit a solution obtained with our Quasi-nonhydrostatic (Q-NH) model that tends toward the reference non-hydrostatic (NH) model. As compared to a pure hydrostatic setting, our Q-NH solution exhibits vertical convective plumes with larger horizontal structure, a better spatial organization and a reduced intensity of their associated vertical velocities. The simulated Mixed Layer Depth (MLD) deepening rate is however too slow in our Q-NH experiment as compared to the reference NH, a behaviour that opposes to that of hydrostatic experiments of producing too fast MLD deepening rate. These preliminary results are encouraging, and support future efforts in the direction of enriching coarse resolution, hydrostatic ocean and climate models with a stochastic representation of non-hydrostatic physics.

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Taomoto, Katsushi, Akihiro Ijichi, Michio Yamaguchi, and Isao Kinoshita. "Clinical Evaluation of Sophisticated Mental Tests and 123I-IMP SPECT in Normal Pressure Hydrocephalus (NPH) Patients." In Hydrocephalus, 637–51. Tokyo: Springer Japan, 1991. http://dx.doi.org/10.1007/978-4-431-68156-4_65.

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Kersting, Annie B., and Mavrik Zavarin. "Colloid-Facilitated Transport of Plutonium at the Nevada Test Site, NV, USA." In Actinide Nanoparticle Research, 399–412. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11432-8_15.

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Armistead-Jehle, Patrick, Robert L. Denney, and Robert D. Shura. "Use of the Word Memory Test (WMT), Medical Symptom Validity Test (MSVT) and Nonverbal Medical Symptom Validity Test (NV-MSVT) in Assessment Following Head Injury." In Detection of Malingering during Head Injury Litigation, 223–43. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-54656-4_5.

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Chippaux, A., S. Chaniot, L. Mouillot, M. C. Crajer, A. Piat, and R. Netter. "Comparison Between NIH and SRD (Single Radial Immunodiffusion) Techniques for Potency Tests of Inactivated Tissue Culture Rabies Vaccines for Human Use." In Rabies in the Tropics, 318–21. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-70060-6_42.

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Pauwelyn, Ann-Sofie, and Sim Turf. "Smart Shipping on Inland Waterways." In Lecture Notes in Civil Engineering, 951–58. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6138-0_84.

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AbstractInland shipping has been struggling with a shortage of skippers for several years. This means, among other things, that smaller vessels disappear and the smaller waterways are no longer used. In addition, it is also difficult for inland shipping to compete with road transport. In time, this will cause a reverse modal shift: cargo will be brought back from the waterway to the road. However, the road is already dealing with a lot of congestion while the potential of the waterway is being used less and less. This will lead to major mobility problems.Over the years, an international consensus has grown that the automation of vessels can be a mean to solve a large part of the above problems and to revive transport via the waterways. In this way, the great pressure on our roads will also be reduced.In order to gain a better insight in the possibilities of Smart Shipping, the PIANC WG 210 was established in 2019. The PIANC INCOM WG 210 Report on Smart Shipping on Inland Waterways has been published in March 2022. This report researches the impact of Smart Shipping developments on the physical and digital infrastructure and on traffic management, with focus on inland waterways. Smart shipping developments were viewed from the perspective of infrastructure providers and traffic managers of inland waterways to stimulate and maximize the deployment of Smart Shipping.The report includes an analysis of the current (until 2019) Smart Shipping developments, what is currently lacking to stimulate Smart Shipping developments, as well as recommendations for the future that can be picked up in other PIANC working groups or research groups. This paper will highlight the findings of the WG and will zoom in on some more concrete examples of Smart Shipping in Belgium, where de Vlaamse Waterweg nv is monitoring a test area in which several 100s of test have taken place since 2019. Recent international legal initiatives will also be described.

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Conference papers on the topic "NVH tests"

Del Sol, Marc, and Roger Mateu. "Global Tool for Objective Data Acquisition for Brake NVH Tests." In Asia Pacific Automotive Engineering Conference. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2013. http://dx.doi.org/10.4271/2013-01-0053.

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Kruse, Enrico, Hendrik Sell, and Florian Loecken. "Electric Motor Mounting System Validation with Subsystem and Powered e-Axle Tests." In Noise and Vibration Conference & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-01-1097.

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<div class="section abstract"><div class="htmlview paragraph">As more and more electric vehicles on dedicated platforms are being developed and launched, motor mounting systems evolve to focus on the specific requirements of the electric drive units (EDUs) – especially the partially opposing targets of controlling powertrain motion under torque and enhancing high frequency isolation. The initial layout of the EDU mounting system, such as the number, position and orientation of the motor mounts as well as their linear and non-linear stiffness properties, during the quotation phase as well as its continuous optimization after business nomination are the foundation for an optimal NVH performance. To support early-stage model validation, Vibracoustic analyzes the modal properties of the EDU or the EDU / subframe assembly to ground. For more comprehensive investigations, Vibracoustic has devised unique axle test rigs to analyze and optimize the NVH of entire axles without the surrounding vehicle. Load cells at all interface points, acceleration sensors and other signal sources permit a comprehensive NVH characterization of an axle. Upgrading the axle test rig with a battery simulator, external liquid cooling and an automation system has enabled the NVH investigation of electric axles under their own power – an industry first. A recently added optical kinematic measurement system now allows the tracking of all 6 DOF motions of any axle and driveline component, e.g. under EDU torque or due to wheel excitations. In this paper, we will share a first correlation study of measurements with multi-body simulations for both test approaches – the simplified experimental modal analysis and the optical kinematic measurement of a full powered e-axle test on a chassis dyno.</div></div>

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Fodorean, D., M. Sarrazin, Claudia Steluta Martis, J. Anthonis, and H. Van der Auweraer. "Characterizing the motorization of a light electric vehicle through FEM and NVH tests." In 2014 XXI International Conference on Electrical Machines (ICEM). IEEE, 2014. http://dx.doi.org/10.1109/icelmach.2014.6960523.

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Zanarini, Alessandro, Filip De Coninck, Krzysztof Mendrok, and Paul Sas. "Direct and Indirect Vibro-Acoustic Measurements for Road Noise NVH Predictions." In ASME 2005 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/detc2005-85633.

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This paper describes vibro-acoustic direct and indirect measurements for road noise NVH predictions from a complete car. Attention is devoted to the dynamic response of the structure and interior pressure field toward tire patch displacement inputs. The direct measurements exploited the Team Corporation CUBE™ high frequency 6 degree-of-freedom (DOF) shaker recently installed at the KULeuven Vehicle Technologies Laboratory; the input was provided directly at the tire contact patch, while the responses were measured as accelerations and pressures on the structure. In the indirect measurements a low-mid frequency volume velocity source (LMFVVS) was used to acoustically excite the structure in the reverse path direction from the inside of the interior car cavity, while accelerations on the car and forces/torques where acquired by a 6-DOF dynamometer at the tire patch. From both types of excitations Frequency Response Functions (FRF) were calculated in the frequency range [0–500 Hz]. The non-linearity of the full car system was investigated with different direct and indirect measurement tests, in order to assess the feasibility of the reciprocity principle in such a complex structure. Measurement set-ups, results and comparisons are described and discussed in detail.

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Soloiu, Valentin, Emerald Simons, Martin Muinos, and Spencer Harp. "NVH of RCCI With DI ULSD and PFI With 50% N-Butanol." In ASME 2015 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/icef2015-1161.

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The noise of diesel engines is dependent upon numerous factors such as: load, speed, fuel injection strategies and fuel type, design of the piston, piston-pin and cylinder and their tolerances, bearings, valves and rocker arm clearances, and designs of the manifolds. In this study, engine sound and vibrations analysis have been conducted using two types of fueling and combustion strategies: classical ULSD combustion and the new RCCI with n-butanol injected in the intake manifold. The analyses add to the understanding of the influence of combustion characteristics’ effect on mechanical noise and vibrations throughout the engine’s operating cycle. The sound and vibration signals were both analyzed in the frequency and angle domain spectrum. Overall NVH spectrum from ULSD combustion was compared to that of RCCI with 50% by mass PFI of n-butanol (the 50% remaining ULSD fuel was directly injected). Frequency analyses were performed using the FFT and CPB methods with Bruel & Kjaer’s Pulse sound and vibrations analysis software. Angle domain analyses were performed, referencing 0 CAD as TDC in combustion. The engine tests were conducted at 1500 rpm and 4 bar IMEP. The COV of IMEP for DI ULSD and RCCI were 2.4 and 2.2, respectively. The correlations between sound, three dimensional vibration levels, and timings were found for: pressure gradients from combustion process, intake and exhaust valve actuations and gas exchange, and piston slap on the cylinder liner. The measurements were extracted and analyzed, and the results determined that virtually all the noise and vibration values pertinent to RCCI were lower than those of ULSD classical combustion.

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Ostermeyer, Georg-Peter, Andreas Krumm, Frank Schiefer, and Sebastian Montua. "Influence of System Boundary Condition on the NVH Behaviour of Bogie Brake Simulation." In EuroBrake 2021. FISITA, 2021. http://dx.doi.org/10.46720/1735035eb2021-stp-010.

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As in many other industries, weight reduction also plays an important role in the product development of train manufacturers and suppliers. Due to the ongoing weight reduction of the bogie and the components, they are becoming increasingly sensitive to NVH phenomena. A particularly critical component here is the brake, as the non-linear friction contact between the brake pad and the disc makes it predestined for self-excited vibration phenomena and thus for NVH phenomena. In this paper, vibration phenomena known from field tests will be investigated with respect to their systemic influence. Three different models of bogie brakes are considered to perform a complex eigenvalue analysis (CEA), where the level of detail of the model and the boundary conditions are different. The first model is a very detailed model of the brake with highly simplified boundary conditions. The second model is an extension of the first model where an additional wheel axle has been added. By including the axle, the brake disc gets additional degrees of freedom, where additional vibrations can be considered. The third model includes an entire wheel set with brake units. This model has been simplified to investigate phenomenologically vibrations of the entire wheelset and to consider systemic influences. With these three models an evaluation of the influence of the boundary conditions on the NVH behaviour should be carried out. For all modal analyses, the real part of the eigenvalue is used as an essential evaluation criterion and is applied to evaluate the impact of the boundary conditions on the observed vibration phenomena or the stability of the eigenfrequencies. Thereby a sensitivity analysis of the individual boundary conditions with respect to the eigenfrequencies is also a target

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Ryu, Keun, and Zachary Ashton. "Bump-Type Foil Bearings and Flexure Pivot Tilting Pad Bearings for Oil-Free Automotive Turbochargers: Highlights in Rotordynamic Performance." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-43927.

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Oil-free turbochargers require gas bearings in compact units of enhanced rotordynamic stability, mechanical efficiency, and improved reliability with reduced maintenance costs compared with oil-lubricated bearings. Implementation of gas bearings into automotive turbochargers requires careful thermal management with accurate measurements verifying model predictions. Foil bearings are customarily used in oil-free microturbomachinery because of their distinct advantages including tolerance to shaft misalignment and centrifugal/thermal growth, and large damping and load capacity compared with rigid surface gas bearings. Flexure pivot tilting pad bearings are widely used in high performance turbomachinery since they offer little or no cross-coupled stiffnesses with enhanced rotordynamic stability. The paper details the rotordynamic performance and temperature characteristics of two prototype oil-free turbochargers; one supported on foil journal and thrust bearings and the other one is supported on flexure pivot tilting pad journal bearings and foil thrust bearings of identical sizes (OD and ID) with the same aerodynamic components. The tests of the oil-free turbochargers, each consisting of a hollow rotor (∼0.4 kg and ∼23 mm in outer diameter at the bearing locations), are performed for various imbalances in NVH (i.e, cold air driven rotordynamics rig) and gas stand test facilities up to 130 krpm. No forced cooling air flow streams are supplied to the test bearings and rotor. The measurements demonstrate the stable performance of the rotor-gas bearing systems in an ambient NVH test cell with cold forced air into the turbine inlet. Posttest inspection of the test flexure pivot tilting pad bearings after the hot gas stand tests evidences seizure of the hottest bearing, thereby revealing a notable reduction in bearing clearance as the rotor temperature increases. The compliant flexure pivot tilting pad bearings offer a sound solution for stable rotor support only at an ambient temperature condition while demonstrating less tolerance for shaft growth, centrifugal and thermal, beyond its clearance. The current measurements give confidence in the present gas foil bearing technology for ready application into automotive turbochargers for passenger car and commercial vehicle applications with increased reliability.

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Wentzel, Richard. "Development Strategies for Creating Quiet Vehicles: Insights from a 35 -Year Veteran." In Noise and Vibration Conference & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-01-1116.

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<div class="section abstract"><div class="htmlview paragraph">From the early 1980’s through 2015, the engineering community has witnessed dramatic changes in the technology for mitigating sound in vehicles. Throughout these years, vehicle noise, vibration, and harshness (NVH) engineers were skilled and talented in testing vehicles, and at conducting laboratory studies of materials and trim-insulator components. This paper surveys a wide variety of processes that NVH automotive engineers use to develop trim-insulator packages which are effective in reducing cab-interior noise while being esthetically appealing. Analytical models are used to cascade overall cab-interior sound pressure level (<i>SPL</i>) targets to trim-insulator performance targets. This paper also reviews how sound absorption is employed to reduce cab-interior <i>SPL.</i> Acoustical material laboratory tests are briefly described along with the role they play in selecting trim-insulator products for vehicles. And finally, body shell acoustical isolation is examined, and a mathematical relationship is derived between cab air-leakage and acoustical degradation.</div></div>

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Bakal, Nikhil, Omkar Prakash Joshi, Prashant R. Pawar, and Vikram V. Shinde. "Generation of Tire Digital Twin for Virtual MBD Simulation of Vehicles for Durability, NVH and Handling Evaluation." In Symposium on International Automotive Technology. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2024. http://dx.doi.org/10.4271/2024-26-0301.

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<div class="section abstract"><div class="htmlview paragraph">With the recent development in virtual modelling and vehicle simulation technology, many OEM’s worldwide are using digital road profiles in virtual environment for vehicle durability load prediction and virtual design evaluation. For precise simulation results, it is important to have the tire digital twin which is the realistic representation of tire in the virtual environment.</div><div class="htmlview paragraph">The study comprises of discussion about different types of tire models such as empirical, solid model, rigid ring model and flexural ring models such as Pacejka, MF Swift, CD tire, F tire etc. and also the complexity involved in development of these tire models.</div><div class="htmlview paragraph">Generation of virtual tire model requires highly sophisticated test rigs as well as vehicle level testing with Wheel Force transducers and other vehicle dynamics sensors. The large number of data points generated with testing are converted in standard TYDEX format to be further processed in various software tool for virtual model generation. Thus, a robust test routine based on laboratory and vehicle level tests to achieve different tire models such as F Tire, MF Tire etc. has been developed. The research paper also discusses the challenges, complexity in data pre and post processing to arrive at the tire characterization for tire digital twinning.</div><div class="htmlview paragraph">In this paper various technical aspects related to passenger car tires, its functions, available tire models, parameterization have been discussed. Additionally, case study has been explained on experience on generation of the digital twin model of tire with Cosin – Ftire software tool. In continuation with process different applications of the Tire models has been elaborated in brief. Tire model developed can be used for vehicle durability, ride & handling simulation, Autonomous driving and ADAS feature development for various OEM’s and tier 1 suppliers. Virtual tire model will aid in reducing the time and physical track testing efforts required in the tire development cycle</div></div>

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Splendi, Luca, Luca D’Agostino, Andrea Baldini, Luca Castignani, Francesco Pellicano, and Marco Pinelli. "Simplified Modeling Technique for Damping Materials on Light Structures: Experimental Analysis and Numerical Tuning." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-64542.

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Specific polymeric and asphaltic materials are widely used for NVH automotive applications. If patches of such materials are properly collocated on vehicle’s panels, they are able to improve significantly noise and vibration performance by modulating damping and stiffness. This work presents a methodology for tuning a FE composite model, using optimization techniques to improve the correlation with the experimental modal tests performed. In particular, plain and ribbed aluminum plates have been considered for several covering ratios of three damping materials. The correlation between numerical and experimental data is achieved by monitoring dynamic parameters such as natural frequencies, mode shapes, and frequency response functions (FRFs). The optimization strategy consists of two steps and makes use of evolutionary and gradient-based algorithms. LMS Virtual.Lab® is used in this part of the work as an environment for correlation and optimization. In order to verify the reliability of the correlation, modal tests are performed on a particular vehicle’s panel.

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Reports on the topic "NVH tests"

Teitsma, Albert. L52091 Better Understanding of Mechanical Damage in Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2004. http://dx.doi.org/10.55274/r0011829.

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This report summarizes work done at the Battelle Memorial Institute, (Nestleroth, 2003) and the Southwest Research Institute (Chell, 2003) on "Better Understanding of Mechanical Damage in Pipelines" for DOT and GTI under the direction of the Gas Technology Institute. Battelle Memorial Institute concentrated on developing MFL technologies for detecting and characterizing mechanical damage defects. Combining axial and circumferential MFL, provides sensitivity to defects of all orientations, accurately determines the width and length of a defect, and more accurately predicts defect depths due to better compensation for geometry generated MFL amplitude changes. High-low magnetization field MFL detects and qualitatively characterizes mechanical defects and provides a quantitative measure of the depth of the initial dent from the reround halo if the pipe has rerounded. Absence of a reround halo would indicate a possibly innocuous defect. Good correlation was found between FEA stresses and strains and the measured NLH results. NLH characterizes mechanical damage qualitatively. Fractographic and metalograhpic analysis after burst tests were used along with engineering judgment and stress calculation to rank the severity of mechanical damage with respect to variation in length width and depth. An empirical formula is proposed for quickly calculating the relative severity of mechanical damage defects. All methods for characterizing mechanical damage, the formula, fractographic and metallographic, MFL, NLH, FEA, and engineering judgment correlated well with each other.

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Megahed, M. RELAP5/MOD2 assessment simulation of semiscale MOD-2C test S-NH-3. Office of Scientific and Technical Information (OSTI), October 1987. http://dx.doi.org/10.2172/6096818.

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Lee, E. J., B. D. Chung, and H. J. Kim. RELAP5 assessment using semiscale SBLOCA test S-NH-1. International Agreement Report. Office of Scientific and Technical Information (OSTI), June 1993. http://dx.doi.org/10.2172/10171705.

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Lahav, Ori, Albert Heber, and David Broday. Elimination of emissions of ammonia and hydrogen sulfide from confined animal and feeding operations (CAFO) using an adsorption/liquid-redox process with biological regeneration. United States Department of Agriculture, March 2008. http://dx.doi.org/10.32747/2008.7695589.bard.

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The project was originally aimed at investigating and developing new efficient methods for cost effective removal of ammonia (NH₃) and hydrogen sulfide (H₂S) from Concentrated Animal Feeding Operations (CAFO), in particular broiler and laying houses (NH₃) and hog houses (H₂S). In both cases, the principal idea was to design and operate a dedicated air collection system that would be used for the treatment of the gases, and that would work independently from the general ventilation system. The advantages envisaged: (1) if collected at a point close to the source of generation, pollutants would arrive at the treatment system at higher concentrations; (2) the air in the vicinity of the animals would be cleaner, a fact that would promote animal growth rates; and (3) collection efficiency would be improved and adverse environmental impact reduced. For practical reasons, the project was divided in two: one effort concentrated on NH₃₍g₎ removal from chicken houses and another on H₂S₍g₎ removal from hog houses. NH₃₍g₎ removal: a novel approach was developed to reduce ammonia emissions from CAFOs in general, and poultry houses in particular. Air sucked by the dedicated air capturing system from close to the litter was shown to have NH₃₍g₎ concentrations an order of magnitude higher than at the vents of the ventilation system. The NH₃₍g₎ rich waste air was conveyed to an acidic (0<pH<~5) bubble column reactor where NH₃ was converted to NH₄⁺. The reactor operated in batch mode, starting at pH 0 and was switched to a new acidic absorption solution just before NH₃₍g₎ breakthrough occurred, at pH ~5. Experiments with a wide range of NH₃₍g₎ concentrations showed that the absorption efficiency was practically 100% throughout the process as long as the face velocity was below 4 cm/s. The potential advantages of the method include high absorption efficiency, lower NH₃₍g₎ concentrations in the vicinity of the birds, generation of a valuable product and the separation between the ventilation and ammonia treatment systems. A small scale pilot operation conducted for 5 weeks in a broiler house showed the approach to be technically feasible. H₂S₍g₎ removal: The main goal of this part was to develop a specific treatment process for minimizing H₂S₍g₎ emissions from hog houses. The proposed process consists of three units: In the 1ˢᵗ H₂S₍g₎ is absorbed into an acidic (pH<2) ferric iron solution and oxidized by Fe(III) to S⁰ in a bubble column reactor. In parallel, Fe(III) is reduced to Fe(II). In the 2ⁿᵈ unit Fe(II) is bio-oxidized back to Fe(III) by Acidithiobacillus ferrooxidans (AF).In the 3ʳᵈ unit S⁰ is separated from solution in a gravity settler. The work focused on three sub-processes: the kinetics of H₂S absorption into a ferric solution at low pH, the kinetics of Fe²⁺ oxidation by AF and the factors that affect ferric iron precipitation (a main obstacle for a continuous operation of the process) under the operational conditions. H₂S removal efficiency was found higher at a higher Fe(III) concentration and also higher for higher H₂S₍g₎ concentrations and lower flow rates of the treated air. The rate limiting step of the H₂S reactive absorption was found to be the chemical reaction rather than the transition from gas to liquid phase. H₂S₍g₎ removal efficiency of >95% was recorded with Fe(III) concentration of 9 g/L using typical AFO air compositions. The 2ⁿᵈ part of the work focused on kinetics of Fe(II) oxidation by AF. A new lab technique was developed for determining the kinetic equation and kinetic parameters (KS, Kₚ and mₘₐₓ) for the bacteria. The 3ʳᵈ part focused on iron oxide precipitation under the operational conditions. It was found that at lower pH (1.5) jarosite accumulation is slower and that the performance of the AF at this pH was sufficient for successive operation of the proposed process at the H₂S fluxes predicted from AFOs. A laboratory-scale test was carried out at Purdue University on the use of the integrated system for simultaneous hydrogen sulfide removal from a H₂S bubble column filled with ferric sulfate solution and biological regeneration of ferric ions in a packed column immobilized with enriched AFbacteria. Results demonstrated the technical feasibility of the integrated system for H₂S removal and simultaneous biological regeneration of Fe(III) for potential continuous treatment of H₂S released from CAFO. NH₃ and H₂S gradient measurements at egg layer and swine barns were conducted in winter and summer at Purdue. Results showed high potential to concentrate NH₃ and H₂S in hog buildings, and NH₃ in layer houses. H₂S emissions from layer houses were too low for a significant gradient. An NH₃ capturing system was designed and tested in a 100-chicken broiler room. Five bell-type collecting devices were installed over the litter to collect NH₃ emissions. While the air extraction system moved only 10% of the total room ventilation airflow rate, the fraction of total ammonia removed was 18%, because of the higher concentration air taken from near the litter. The system demonstrated the potential to reduce emissions from broiler facilities and to concentrate the NH₃ effluent for use in an emission control system. In summary, the project laid a solid foundation for the implementation of both processes, and also resulted in a significant scientific contribution related to AF kinetic studies and ferrous analytical measurements.

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Zavarin, M. Yields and Cavity Radii of Underground Nuclear Tests with Specified Yields Reported in DOE/NV -- 209-REV 15 (2000). Office of Scientific and Technical Information (OSTI), November 2014. http://dx.doi.org/10.2172/1179117.

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ITLV. Corrective Action Investigation Plan for Corrective Action Unit 500: Test Cell A Septic System, Nevada Test Site, Nevada, Revision 0, DOE/NV--528 UPDATED WITH TECHNICAL CHANGE No.1. Office of Scientific and Technical Information (OSTI), December 1998. http://dx.doi.org/10.2172/8810.

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Author, Not Given. Addendum to: Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) for Corrective Action Unit (CAU) 443: Central Nevada Test Area (CNTA)-Subsurface Central Nevada Test Area, DOE/NV-977. Office of Scientific and Technical Information (OSTI), January 2008. http://dx.doi.org/10.2172/1114521.

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US DOE Nevada Operations Office. Record of Technical Change {number_sign}1 to ''Corrective Action Investigation Plan for Corrective Action Unit 261: Test Cell A Leachfield System, Nevada Test Site, Nevada,'' Revision 0, DOE/NV-519. Office of Scientific and Technical Information (OSTI), February 2000. http://dx.doi.org/10.2172/751162.

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BECHTEL NEVADA and NNSA NEVADA SITE OFFICE. RECORD OF TECHNICAL CHANGE CAP-2 FOR CORRECTIVE ACTION PLAN FOR CORRECTIVE ACTION UNIT 204: STORAGE BUNKERS, NEVADA TEST SITE, NEVADA, REVISION 0, SEPTEMBER 2004, DOE/NV--1003. Office of Scientific and Technical Information (OSTI), June 2005. http://dx.doi.org/10.2172/850238.

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USDOE Nevada Operations Office. Record of Technical Change {number_sign}2 for ''Corrective Action Investigation Plan for Corrective Action Unit 240: Area 25 Vehicle Washdown, Nevada Test Site, Nevada,'' Revision 0, DOE/NV--532. Office of Scientific and Technical Information (OSTI), March 2000. http://dx.doi.org/10.2172/751164.

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