• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.57-63
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• 1998

In this paper, a design tool using continuum design sensitivity analysis (DSA) method has been developed for noise, vibration, and harshness (NVH). Design sensitivity is formulated, implemented numerically, and named SENS1. SENS1 can compute the design sensitivity using model and response files of MSC/NASTRAN of vehicle. A of real vehicle model is considered to validate SENS1. Numerical study shows SENS1 is a useful tool to improve NVH performances of vehicle body.

• Journal of KSNVE
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• v.6 no.2
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• pp.127-133
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• 1996

이 글에서는 부밍소음의 현상과 특성, 발생 메카니즘, 원인규명 방법 및 대책 방법에 대해 알아보았다. 개발 차량이 제작되고 나서 양산 단계까지의 NVH (Noise, Vibration and Harshness) 육성에 초점을 두어 트러블슈팅(troubleshooting) 위주로 서술 하였으나, 이단계에서 NVH 대책을 세우는 것은 시간이 오래 걸릴 뿐 아니라 대책안 적용에 소요되는 비용도 문제가 될 수 있다. NVH 성능이 우수한 차량 을 조기에 개발하기 위해서는 NVH가 고려된 설계가 필수적이다. 설계 단계에서 CAE 해석을 하여 NVH 성능을 미리 예측하고, 설계 미스가 있을 때는 차량이 제작되기 전에 미리 대책을 세움으로써 효율적인 차량 개발을 할 수 있다.

• The Journal of the Acoustical Society of Korea
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• v.37 no.4
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• pp.242-247
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• 2018

The automotive industry is making various efforts to cope with ever-increasing exhaust emissions and fuel economy regulations. However, this often results in degraded NVH (Noise, Vibration, and Harshness) performance. For example, we proposed the causes and improvements for the noise generated by the high-pressure pump noise of a gasoline engine, the change of acceleration noise due to dual injection of MPI (Multi-Point Injection) and GDI (Gasoline Direct Injection), the noise of a gasoline turbocharger, and the combustion noise deteriorated due to the injection parameters calibration in a diesel engine. Since these noises are caused by the high frequency noise, and the driver feels the rough sound quality, efforts to reduce them with proper NVH measures are indispensable.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.483-488
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• 2013

The psychoacoustic quality of ABS is now considered more important than before as the focus of recent ABS function is expanded to basic function from typical emergency function. Thus, the automotive parts manufacturing companies are actively working to improve NVH (Noise, Vibration, and Harshness) in ABS module. In terms of time, test place, and cost, however, it is very inefficient to have all the operating noise validation test in real vehicle configuration especially for partially improved ABS module. To contribute to reducing the development period and to grasping the improvements faster, this research presents the study of a correlation to predict ABS operating noise inside vehicle via HILS rig test. The regression equation in this paper was statistically drawn from using Minitab S/W, and based on that equation, the noise spectrum of vehicle interior was analogized.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.622-625
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• 2007

For optimizing the performance of SI engine such as engine torque, fuel consumption, and emissions, systems for variable valve timing were developed by many automotive researchers. In this work, we investigated the relationship between valve timing and intake orifice noise to improve the NVH (Noise, Vibration and Harshness) performance as well as engine torque and power. Two approaches are conducted, which are engine dynamometer testing and 1-D simulation analysis. Experimental data were measured on about 21 different operating conditions. This experiment shows that the intake and exhaust valve timing related to overlap period influence on the NVH performance, especially intake orifice noise of engine at given range of operation conditions. Similar results are achieved by using 1-D simulation analysis. It is concluded that the optimal strategies of controlling valve timing and tuning intake systems, are necessary to develop engines or vehicles with good sound quality.

• Journal of Mechanical Science and Technology
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• v.17 no.7
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• pp.958-965
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• 2003

Structural integrity of either a passenger car or a light truck is one of the basic requirements for a full vehicle engineering and development program. The results of the vehicle product performance are measured in terms of ride and handling, durability, noise/vibration/harshness (NVH), crashworthiness and occupant safety. The level of performance of a vehicle directly affects the marketability, profitability and, most importantly, the future of the automobile manufacturer In this study, we used the virtual proving ground (VPG) approach for obtaining the dynamic characteristics. The VPG approach uses a nonlinear dynamic finite element code (LS-DYNA3D) which expands the application boundary outside the classic linear static assumptions. The VPG approach also uses realistic boundary conditions of tire/road surface interactions. To verify the predicted dynamic results, a single lane change test has been performed. The prediction results were compared with the experimental results, and the feasibility of the integrated CAE analysis methodology was verified.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.4665-4671
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• 2013

Engine mounting system is the most responsible system for NVH performance of vehicle. The vibration at idle shake, road shake, Key ON/OFF, gear shift tuned by the engine mount position and stiffness. Previously described Engine mounting system theory investigated and summarized in this paper. Decoupling of the Power train rigid mode and Reducing the angle between Torque-Roll-Axis and Elastic-roll-Axis is starting point of optimization. Multi-optimization analysis was performed because of variety simulation case and FE-model. Eventually, Find the best mount location and the stiffness has improved the performance of the vehicle NVH.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.104-109
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• 1996

Continuum element sensitivity analysis (CONTESA) and system optimization (SYSOPT) for Noise, Vibration, and Harshness (NVH) have been developed and applied to automobile structures for sizing, topology, and configuration design using Mindlin plate and Timoshenko beam theories. The topology optimization has been developed using the density approach, sequential linear programming, and the adjoint variable method. CONTESA has been tested using various vehicle models. Optimized vehicles using CONTESA and SYSOPT are manufactured to validate the simulation-based design methodology.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.4
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• pp.291-298
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• 2011

According to the developments of automobile industry, the technology to enhance noise, vibration and harshness(NVH) performance has been studying in a point of view of ride comfort and quietness. Especially the use of computer aided engineering(CAE) simulation tools such as finite element(FE) analysis allows engineers to efficiently evaluate NVH performance. This paper presents the method to bulid FE models for full vehicle including engine, transmission. suspension and steering system, also to evaluate vibration performance of full vehicle. The full vehicle model, which is discussed, is correlated with the result of the frequency response measurement in the case of the car shake performance for high speed driving.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1151-1156
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• 2002

This paper describes the examples of Noise, Vibration and Harshness(N.V.H) development applying Computer Aided Engineering(CAE). Some Commercial Software was used to reduce the cost, development time and to predict the Noise and vibration phenomenon of new vehicle design. This paper is including measured and analysis data, and tried to prove the good correlation between measured and calculated data, so test and analysis data were compared seriously and carefully. Analysis models, which were used to predict and develop the NVH phenomenon, analysis method, and a field of --0application are explained briefly. Also, model pictures are presenting in this paper. This paper describes the analyzing method of the calculated results, design modification and development procedure, and NVH performance target setting up and procedure.