타이어 트레드의 진동에 의한 음향방사

김병삼,홍동표,정태진,Kim, Byoung-Sam,Hong, Dong-Pyo,Chung, Tae-Jin 한국음향학회 1994 韓國音響學會誌 Vol.13 No.2

회전하는 타이어의 표면진동에 의한 소음방사의 이론적인 모델에 대하여 연구하였다. 타이어를 원형링으로 가정하였고 정규주파수와 구조적인 손실계수를 고려하였다. 타이어 전표면에 대한 음압의 수치적분을 통하여, 타이어로부터 방사되는 음향파워를 계산하였다. 가진주파수와 손실계수를 고려한 계산 결과로부터 타이어 트레드 진동에 의한 음향방사를 감소시키기 위한 조건을 구하고자 하였다. A theoretical model is studied to describe the sound radiation by the surface vibration of in-service tires. The tire is modeled as a circular ring model. The effects of normalized frequency and structrual loss factor are included. Through numerical integration of the sound pressure, the radiated sound power is calculated as a fuction of normalized frequency and structural loss factor. The basic sound radiation mechanism is shown to be the damped progressive wave field on the structure in the vicinity of the applied force. The results indicate that the potential sound reduction might be obtained if values of normalized frequency and structural loss factor are investigated.

Pt / super acid 촉매상에서 디젤 매연의 접촉연소반응

김병삼,김기석 ( Byoung Sam Kim,Ki Seok Kim ) 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.2

하중을 받고 회전하는 승용차 타이어의 반경방향 고규진동수 측정에 관한 실험적 연구

김병삼,홍동표,지창헌,Kim, Byoung-Sam,Hong, Dong-Pyo,Chi, Chang-Heon 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.1

The measurement of radial directional natural frequency ina passenger car tire rotating under the load is studied. In order to obtain theoretical matural frequency and mode shape, the ploane vibration of a tire is modeled to that of circular beam. By esing the Tieking method based on Hamiltons's principle, theoretical results are determined by considering tension horce due to tire inflation pressure, retational velocity and tangential, radial stiffness. Radial directional modal parameters varying with the inflation pressure, load, rotational velocity are experimentally determined by using frequency response function method. The results show that experimental conditions canbe considered as the parameters which shift the natural frequency.

음장의 공간적 변환기법을 이용한 타이어 구조 진동 소음 측정

김병삼,Kim, Byoung-Sam 한국음향학회 1995 韓國音響學會誌 Vol.14 No.5

본 논문에서는 불규칙한 노면이 설치된 섀시 동력계(chassis dynamometer)로 부터 가진된 타이어의 구조 진동 소음을 음장의 공간적 변환기법을 이용하여 측정하였다. 음장의 공간적 변환기법은 소음원으로 부터 원거리까지의 전파를 계산하는 기법이다. 즉, 한평면의 음향 측정으로 부터 측정 평면에서 멀리 떨어지거나 더 가까운 평면에서의 음장을 표현하는 변수들인 음압, 음향 인텐시티, 입자속도 등을 계산한다. 측정 평면에서 음원쪽으로 가까운 평면의 계산은 관접음장 홀로그래피를 적용하여 계산하고 먼 쪽은 헬름흘쓰 적분식을 적용한다 측정결과로 부터 타이어 구조 진동 소음의 방사형태와 소음원의 위치를 예측하였다. The Interaction between tire and road is responsible for the excited vibration of the tire, and It is also important for the sound radiation. In this paper. measurement of tire structural vibration noise from a chassis dynamometer using Spatial Transformation of Sound Field(STSF) technique is studied. STSF involving a scan that uses an array of transducers over a planar surface close to the source is under investigation. From cross spectra measurement during the scan, a principal component representing the sound field is extracted. Any power descriptor of the near field can then be investigated by means of near-field acoustic holography, while the distant field can be determined by application of Helmholtz integral equation. The results of the measurement were used to obtain the radiation sound pattern from the center line of the tire, and to locate the radiation sound generating regions in the vicinity of the tire.

선박건조 및 수리업의 소음 저감 대책

김병삼(Kim Byoung Sam),이인섭(Lee In Seop),김갑배(Kim Kab Bae) 한국생산제조학회 2011 한국생산제조시스템학회 학술발표대회 논문집 Vol.2011 No.4

There is a considerable amount of research on ship worker’s hearing loss caused by vibration and noise that comes from the ship’s construction. A further investigation that characterizes the sound that comes from building or repairing a ship is nonexistent or insufficient, however. To do this, a noise management plan is needed. It should include a generated sound process from the main sources of disturbance in the ship-building areas. And a soundproof measurement will identify the amount of noise reduction needed for a hearing-safe working environment. Finally, researchers in this study measured tests on the noise and the vibration process, and the noise caused by operations allowed for an investigation on the suitability of certain environmental conditions. Noise-related programs can be used to predict the noise distribution of the noise level characteristic. This can help identify and reduce the presence of sound interference through sound proofing measures.

자동차 배기 소음 저감을 위한 환상형 소음기

김병삼 ( Byoung-sam Kim ),김형두 ( Hyung-doo Kim ) 한국환경기술학회 2014 한국환경기술학회지 Vol.15 No.3

자동차 엔진은 환경오염의 주 원인중 하나이기 때문에 전 세계적으로 배기가스로 인한 피해를 최소화하기 위한 기술이 필요하다. 특히, 배기가스는 자동차 소음기로 배출되고 배기소음은 주변 환경에 매우 유해하다. 배기소음을 저감하기 위하여 자동차 소음기는 최적으로 배출 효율을 가질 수 있도록 설계되어야 한다. 본 연구에서는 배기가수 소음, 소음분포 특성, 배기가스의 압력과 온도에 대하여 공냉 환상형 자동차 소음기의 온도를 변화시키면서 조사하였다. 자동차 소음기의 주파수 해석으로 부터 소음분포는 1,000~2,000Hz 대역이고, 소음저감은 환상 온도에 영향을 받고 있음을 알 수 있었다. Internal combustion engine is the main source of environmental pollutants and therefore advanced technology is required to reduce harmful elements from the exhaust gases all over the world. Especially, when the exhaust gas is released from the automotive muffler, exhaust noise has many bad influence on the surrounding environment. In order to reduce the exhaust noise, it is necessary that automotive muffler must be designed for best exhaust efficiency. The sound insulation room was installed for the analysis of an acoustics characteristics of the noise from automotive muffler, in this study. Exhaust gas noise, noise distribution characteristics, pressure and temperature of exhaust gas were investigated with the change of annulus temperature of air cooled annulus automotive muffler and cooled annulus automotive muffler. The following results were obtained with this study. From the frequency analysis of automotive muffler, high noise distribution was observed in the range 100~2,000Hz. It means that the noise in this range has an dominate influence for the overall noise. Noise reduction of automotive muffler was affected by the temperature of annulus. It is caused the result that the high temperature and pressure of exhaust gas are changed lower by the drop of annulus temperature. The tendencies of noise, the temperature and pressure of exhaust gas are similar to the performance curve of engine. Exhaust gas pressure is determined by the revolution per minute of engine and affected by the cooling performance of automotive muffler.

자동차 타이어 패턴소음 예측에 관한 연구

김병삼(Byoung-Sam Kim) 한국자동차공학회 2011 한국자동차공학회 지부 학술대회 논문집 Vol.2011 No.5

Tire manufactures have dealt with noise problem by varying the pitch of the tread. The various formulas for the variations are generally determined differently, however. Often these variations are based on a combination of trial and error, intuition, and economics. Some manufactures have models and analogs to test tread patterns and their variations. These efforts, however practical, do not determine the best variation beforehand or guarantee the best results. For this reason it was felt that a general mathematical approach for determining the best variation was needed. Moreover, the method should be completely general, easy to use, and sufficiently accurate. This paper discusses a mathematical method called Mechanical Frequency Modulation(MFM) which meets the above requirements. Thus, MFM pertains to computing an irregular time sequence of events so that the resulting excitation spectrum is shaped to a preferred form. The first part of this paper treats the theoretical basis for computing an optimum variation; the second part discusses experimental results and simulation program which corroborate the theory.

타이어의 진동특성에 관한 실험적 연구

김병삼 ( Byoung-sam Kim ),장일도 ( Il-do Chang ),지창헌 ( Chang-heon Chi ) 한국환경기술학회 2006 한국환경기술학회지 Vol.7 No.2

차량 제조기술의 급격한 발전과 환경문제에 대한 관심의 고조로 인하여 승차감과 정숙성이 차량의 성능 평가에 중요한 요소로 등장하고 있다. 따라서 차량 주행시 발생하는 진동과 소음현상에 대한 연구가 증가하고 있으며, 이러한 현상을 평가하기 위한 측정방법과 해석기술도 활발히 개발되고 있다. 본 연구에서는 주파수 응답함수법을 이용하여 현가장치가 부착되지 않은 타이어의 고유진동수와 감쇠비를 실험적인 방법으로 측정하였다. 구속받지 않는 실험조건 하에서 여러 가지 타이어(승용차에서 트럭 버스 타이어까지)의 반경방향 고유진동수와 감쇠비을 측정하였다. 타이어의 반경방향 모달 파라메타는 타이어 내부 공기압에 따라 변하였다. 내부 공기압, 타이어에 가해지는 하중 등 실험조건의 변화에 따라 고유진동수와 감쇠비는 변하였다. Natural frequencies and damping ratio of tire without suspension are investigated using frequency response function method. In this paper, we have reported natural frequencies and damping ratios in the radial direction of various tires, from PCR(passenger car radial) tires to truck bus tires, under unconstrained condition. We have determined the radial directional modal parameters of tires, which are subjected to different levels of inflation pressure, by using frequency response function method. The results show that experimental conditions shift the natural frequency and damping ratio.

자동차용 알루미늄 합금 휠의 진동특성에 관한 실험적 연구

김병삼(Byoung-Sam Kim),김기전(Gi-jeon Kim),이태근(Tae-Keun Lee),이규철(Gyu-Cheol Lee) 한국자동차공학회 2003 한국자동차공학회 지부 학술대회 논문집 Vol.2003 No.5

The styling of automobile wheels and their effect on vehicle appearance has increased in importance in recent years. The wheel designer has been given the task of insuring that a wheel design meets its engineering objectives without affecting the styling theme. The wheel and tire system is considered as a vehicle component whose dynamic modal information of the tire/wheel system are employed in the modal synthesis model of the vehicle. The Vibration characteristics of a passenger car wheel play an important role to judge a ride comfortability and quality for a passenger car. In this paper, the vibration characteristics of a AI-alloy and steel wheel for passenger car are studied. Natural frequency, damping and mode shape are determined experimentally by frequency response function method. Results show that wheel material property, size and design are parameter for shift of natural frequency and damping.<br/>

자동차 타이어의 유니포미티에 관한 연구

김병삼(Byoung-Sam Kim) 한국자동차공학회 2012 한국자동차공학회 지부 학술대회 논문집 Vol.2012 No.5-2