• Title/Summary/Keyword: Squeak

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A Basic Experimental Study on the Squeak Noise Using the Pin-on-disk (Pin-on-disk를 이용한 기초 마찰소음 실험 연구)

  • Nam, Jae-Hyun;Kang, Jae-Young
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.8
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    • pp.736-741
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    • 2012
  • Squeak noise is studied by using the pin-on-disk system with aluminum pin and steel disk. Noise induced by friction is measured with respect to the normal loads and sliding speeds. The negative slope of friction-velocity curve is seen when the squeak noise occurs. It is found that the normal load influences on the sound level of squeak noise. From the hammering test, the major frequency of the squeak noise is shown to correspond to one of system modes, which implies that squeak phenomenon arises from the unstable system modes. The result of FE analysis shows that the major squeak mode is the bending mode of the pin.

Observation and Characterization of Squeak Noises of Polymeric Materials for Automotive Interior Parts Under Field-Degradation (자동차 내장재용 고분자 재료의 필드 열화에 따른 마찰소음 특성변화)

  • Lee, Changhun;Kang, Byunghyun;Choi, Byoung-Ho;Lee, Jongho;Lee, Kwanghee
    • Transactions of the Korean Society of Automotive Engineers
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    • v.25 no.2
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    • pp.257-265
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    • 2017
  • In this work, the effect of field-degradation of automotive polymeric interior parts on the squeak characteristics was studied for a number of used vehicles with various mileages and years of service. The purpose of this study was to characterize the squeak noise related with long-term degradation in service life. The characteristics of field-degraded polymeric samples are analyzed using Fourier transform infrared(FT-IR) spectroscopy and scanning electron microscopy(SEM). Complicated carbonyl spectra from FT-IR were deconvoluted into various carbonyls to trace field-degradation phenomenon. In addition, various mechanical tests, i.e. tensile test, hardness test as well as coefficient of friction test, were performed to analyze the variation in mechanical properties due to field-degradation. Squeak noise was measured and analyzed by frequency analysis. It was shown that the changes in the chemical structures of polymer due to field-degradation influenced the variation in mechanical properties, and squeak noise may worsen by increasing the squeak noise level in the wide frequency range. The results indicated that customer complaints regarding the squeak noise coming from used vehicles might be one of the important reliability issues because the increase in sound pressure level especially in the high frequency range could annoy drivers and passengers.

Squeak Noise of Ceramic-on-ceramic Hip Joint using FEM (FEM을 이용한 세라믹-세라믹 고관절 마찰소음의 불안정성 해석에 관한 연구)

  • Nam, Jaehyun;Kang, Jaeyoung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.12
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    • pp.1090-1095
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    • 2013
  • This paper describes the FEM analysis for squeak problem of the ceramic-on-ceramic hip joint system. The onset of hip squeak is estimated by the positive real parts of the eigenvalues in the hip joint system. From the complex eigenvalue analysis, the unstable frequencies and the corresponding mode shapes are determined at the certain severe friction coefficients. It is found that some bending and torsion modes of the femoral stem can be unstable due to the mode-coupling mechanism. It also shows that the magnitude of the friction coefficient plays a key role on the occurrence of hip squeak.

Comparison on How Much Dolittle and Squeak Languages Influence Improving Elementary Students' Logical Thinking Capability (두리틀과 스퀵 언어가 초등학생의 논리적 사고력 신장에 미치는 영향 비교)

  • Kim, Young-Ae;Lee, Bong-Kyoo;Kim, Byung-Soon
    • Journal of Digital Contents Society
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    • v.10 no.3
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    • pp.375-380
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    • 2009
  • Computer programming education can improve students' logical thinking and problem-solving ability. Therefore, it is essential tool to improve algorithmic thinking ability. We study how much Dolittle and Squeak influences improving elementary students' logical thinking ability. Thus, we divided 6th grade elementary students into two classes and then taught Dorittle and Squeak programming languages for 6 weeks, respectively. We compare and analyze each logical thinking ability and its sub-classifications. The results showed that Dorritle affects significant improvement, but not Squeak.

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The Effects of Algorithm Learning with Squeak Etoys on Middle School Students' Problem Solving Ability (Squeak Etoys 활용 알고리즘 학습이 중학생의 문제해결력에 미치는 영향)

  • Jeoung, MiYeoun;Lee, EunKyoung;Lee, YoungJun
    • 대한공업교육학회지
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    • v.33 no.2
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    • pp.170-191
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    • 2008
  • Many former researchers demonstrated that algorithm learning has a positive outcome on students' problem-solving abilities. One of the methods for algorithm learning, the 'programming learning' method is highly effective. However, there are numerous constraints in schools for programming learning. This study attempts to overcome these issues. Squeak Etoys, one of the educational visual programming languages for easy and interesting learning, has been selected as a learning tool. We developed the algorithm-learning curriculum for middle school students. They were divided into a control group and an experimental group. The students learned on the basis of equal curriculum but, they used other learning tools through over a total 6 sessions. The result showed that Squeak Etoys based Algorithm learning has a positive effect on improving middle school learners' problem solving abilities, self-efficacies and logical thinking abilities. Although the students' logical thinking abilities in the experimental group are improved a lot more than the students' abilities in control group, the students' logical think abilities in the both groups are improved. Therefore, algorithm education in secondary schools are necessary. In conclusion, Squeak Etoys based Algorithm learning has a positive effect on problem solving ability and self efficacy. The developed curriculum can be applicable as a basis for study on algorithm learning and educational programming language.

An Experimental Approach and Improvement of Buzz, Squeak and Rattle Noise from a Seat (차량 시트의 BSR Noise에 대한 시험적 고찰 및 개선)

  • Jeon, Jun-Sig;Kim, Byung-Hoon;Bang, Byung-Ju;Jang, Ik-Guen;Ji, Sung-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.675-679
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    • 2006
  • Today, the interior noise perceived by the occupants is an important factor in the design of automotive interior assemblies. Buzz, Squeak and Rattle Noises in a Seats are one of the major concerns mentioned above. In this study, the terms 'Buzz, squeak and rattle' were defined as the noise originating from structural vibrations in an assembly. And, the BSR noise of vehicle seat was investigated and the improvement of BSR noise level was confirmed though the structural treatment based on the structural analysis results from the modal and sound intensity of seat.

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Effects on Metacognition and GALT Logical Thinking Ability in Programming Educations using Squeak e-toy (스퀵 e-toy 프로그래밍 교육을 통한 메타인지 및 GALT 논리 사고력 향상 효과 분석)

  • Jong, You-Rim;Hur, Kyeong
    • Journal of The Korean Association of Information Education
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    • v.14 no.2
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    • pp.199-207
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    • 2010
  • This paper is proposed to present elementary algorithmic thinking-based Squeak E-toy programming problems for flowchart-based programming educations without programming languages in elementary programming educations. Furthermore, this paper proves the validity and effects of developed Squeak E-toy programming problems through measurement analyses of metacognition and GALT logical thinking ability experiments by comparing with the language-based traditional programming education.

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Tilting Effect of Automotive Seat System on Squeak Noise (자동차 시트 틸팅 각도에 따른 기어박스 마찰소음 영향도)

  • Kang, Jae-Young
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.6
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    • pp.577-582
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    • 2010
  • The squeak propensity in the gear box of an automotive seat system is investigated analytically. The mating parts in the gear box are the lead screw and the nut, where the friction stresses are exerted on the thread of the screw. The lead screw is modeled as a circular beam allowing the bending and torsional vibrations. In the system, the lead screw converts rotating to translating motion so that it moves the automotive seat slightly tilted on the floor. The tilting angle is considered one major parameter in this study. Therefore, the equations of motion associated with the non-conservative friction force are derived with the inclusion of the tilting angle. It is found that the squeak noise corresponds to the several bending modes of the lead screw and its propensity is increased by the tilting angle of the seat.

BSR (Buzz, Squeak, Rattle) noise classification based on convolutional neural network with short-time Fourier transform noise-map (Short-time Fourier transform 소음맵을 이용한 컨볼루션 기반 BSR (Buzz, Squeak, Rattle) 소음 분류)

  • Bu, Seok-Jun;Moon, Se-Min;Cho, Sung-Bae
    • The Journal of the Acoustical Society of Korea
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    • v.37 no.4
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    • pp.256-261
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    • 2018
  • There are three types of noise generated inside the vehicle: BSR (Buzz, Squeak, Rattle). In this paper, we propose a classifier that automatically classifies automotive BSR noise by using features extracted from deep convolutional neural networks. In the preprocessing process, the features of above three noises are represented as noise-map using STFT (Short-time Fourier Transform) algorithm. In order to cope with the problem that the position of the actual noise is unknown in the part of the generated noise map, the noise map is divided using the sliding window method. In this paper, internal parameter of the deep convolutional neural networks is visualized using the t-SNE (t-Stochastic Neighbor Embedding) algorithm, and the misclassified data is analyzed in a qualitative way. In order to analyze the classified data, the similarity of the noise type was quantified by SSIM (Structural Similarity Index) value, and it was found that the retractor tremble sound is most similar to the normal travel sound. The classifier of the proposed method compared with other classifiers of machine learning method recorded the highest classification accuracy (99.15 %).

Basic principle of BSR (Buzz, Squeak, Rattle) noise according to the generation mechanism (BSR(Buzz, Squeak, Rattle)이음 발생 메커니즘 기본 원리와 시험평가 방법)

  • Choi, Sung uk;Ahn, Sungcheul;Ih, Kang Duck
    • The Journal of the Acoustical Society of Korea
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    • v.37 no.5
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    • pp.309-316
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    • 2018
  • Various studies have been conducted to improve the BSR (Buzz, Squeak, Rattle) noise generated irregularly while the vehicle is running. In vehicle, When an external force such as vibration or force flows into the contact surface, BSR noise is generated at the contact surfaces of nearby components. In this paper, BSR conceptually explain the kind of noise generation mechanisms and the basic principles of generation, which have been proven by observing and improving noise phenomena in automobiles over the last 10 years. Through this, it is expected that researchers who want to study BSR related improvement research not only in automobiles but also in other industries, It will be able to understand the BSR phenomenon and provide a framework for thinking out improvement ideas and to carry out further research.