• 제목/요약/키워드: Harshness

검색결과 86건 처리시간 0.025초

비선형 유한요소 해석프로그램(LS-DYNA)을 이용한 차량 동력학해석 (Vehicle Dynamic Analysis Using Nonlinear Finite Element Analysis Program(LS-DYNA))

  • 민한기;이현;양인영
    • 한국안전학회지
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    • 제17권3호
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    • pp.36-42
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    • 2002
  • 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. VPG approach uses a nonlinear, dynamic, finite element code(LS-DYNA3D) which expands the application boundary outside the classic linear, antic assumptions. 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 test results, and the feasibility of the integrated CAE analysis methodology was verified.

거친 청감을 유발하는 엔진소음 개선 방향 고찰 (Improvement of engine noise causing rough sound quality)

  • 정인수;김석준;조덕형
    • 한국음향학회지
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    • 제37권4호
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    • pp.242-247
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    • 2018
  • 지속적으로 강화되는 배기가스 및 연비 규제에 대응하기 위해 자동차 업계에서는 다양한 노력을 하고 있다. 하지만 이로 인해 NVH(Noise, Vibration, and Harshness) 성능이 악화되는 경우들이 많이 발생하고 있다. 사례로 가솔린 엔진의 고압 펌프 소음 및 MPI(Multi-Point Injection)와 GDI(Gasoline Direct Injection)의 듀얼 분사로 인한 가속 천이 소음, 가솔린 터보차저 소음, 디젤 엔진에서의 분사변수 캘리브레이션으로 인해 악화되는 연소음에 대한 원인 및 개선방향을 제시하였다. 이러한 소음들은 고주파 소음으로 운전자에게 거친 청감을 유발하기 때문에 적절한 NVH 대책으로 저감시키는 노력이 반드시 필요하다.

HILS Rig 시험을 통한 실차 ABS 실내작동소음 예측 기법에 대한 연구 (Research on Correlation Method of ABS Interior Operational Noise via HILS Rig Test)

  • 김승환;육지용;한민규;전남일
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2013년도 추계학술대회 논문집
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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.

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Topology Optimization of a Lightweight Multi-material Cowl Cross Member Using Matrix Input with the Craig Bampton Nodal Method

  • Son, Dong il;So, Sangwoo;Choi, Dong hyuk;Kim, Daeil
    • Composites Research
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    • 제32권5호
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    • pp.243-248
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    • 2019
  • As demand of light weight in the automotive industry has increased, the cowl cross member has been investigated using various methods to change the material. Conventionally, a cowl cross member has been made of steel and aluminum, but recently researchers tested multi-material such as aluminum and plastic. We studied a new model of the cowl cross member made of composite and non ferrous materials. For products with a high degree of freedom in design, generally, the method of topology optimization is advantageous and for the partial bracket part of the cowl cross member had a degree of freedom in the design, a topology optimization is appropriate. Considering the characteristics of the cowl cross members, we need research to minimize the weight while having the performance of noise, vibration and harshness(NVH). Taking the mounting status of the product into consideration, we used an assembly model to optimize the cowl cross member. But this method took too much time so we considered simple cowl cross member assemble conditions using the direct matrix input method(DMI) with the Craig-Bampton Nodal Method. This method is capable of considering the status of the assembly without assembling the model, which reduced the solving time and increased the accuracy comparison with a cowl cross member without DMI.

배기정화용 촉매장치의 열화 모사 (Simulated Degradation of a Catalytic Converter)

  • 임명택;위전석
    • 한국자동차공학회논문집
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    • 제10권1호
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    • pp.45-50
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    • 2002
  • Use of a phenomenological model, developed far prediction of catalytic deactivation, is demonstrated in comparing harshness of different driving cycles that are currently used to rapidly age catalytic converters on engine test benches. The model shows that seemingly equivalent driving cycles cause the catalytic converters to reach significantly different levels of deactivation. The comparison of the model prediction with the limited vehicle data seems encouraging despite the simplicity of the model at the current stage of its infancy.

자동차 소음, 진동 저감을 위한 차체 설계 프로그램 개발 (Design Tool Development of NVH of Vehicle Body)

  • 왕세명;이제원;기성현;문희곤;서진관
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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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.

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자동차의 부밍 소음 저감

  • 정해일
    • 소음진동
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    • 제6권2호
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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.

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소비자 중재합의의 부합계약성에 관한 검토 - 미국법을 중심으로 - (Review on the Adhesiveness of Consumer Arbitration Agreements: U.S. Laws)

  • 하충룡
    • 한국중재학회지:중재연구
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    • 제22권3호
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    • pp.47-69
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    • 2012
  • This paper investigates the U.S. courts'attitudes toward the legal doctrine of adhesion contracts, which have been employed as contract defenses by individual consumers who have entered into consumer arbitration agreements with businesses. Some requirements have been added to the sole adhesiveness of the arbitration clause that can invalidate the arbitration clause, including unconscionability and unreasonable harshness. It seems that the U.S. courts have moved toward a more tightened stance in evaluating the validity of consumer arbitration clauses, favoring consumer arbitration.

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자동차 소음/진동의 최적 설계 (Design Optimization of Structure-born Noise of Automobile)

  • 왕세명;최경국;하리쿨카니
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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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.

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