• Title/Summary/Keyword: Complex stress

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A Strength Analysis of Gear Train for Hydro-Mechanical Continuously Variable Transmission

  • Bae, Myung Ho;Bae, Tae Yeol;Yoo, Young Rak
    • International Journal of Advanced Culture Technology
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    • v.6 no.3
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    • pp.163-172
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    • 2018
  • The power train of hydro-mechanical continuously variable transmission(HMCVT) for the middle class forklift makes use of an hydro-static unit, hydraulic multi-wet disc brake & clutches and complex helical & planetary gears. The complex helical & planetary gears are a very important part of the transmission because of strength problems. The helical & planetary gears belong to the very important part of the HMCVT's power train where strength problems are the main concerns including the gear bending stress, the gear compressive stress and scoring failures. The present study, calculates specifications of the complex helical & planetary gear train and analyzes the gear bending and compressive stresses of the gears. It is necessary to analyze gear bending and compressive stresses confidently for an optimal design of the complex helical & planetary gears in respect of cost and reliability. This paper not only analyzes actual gear bending and compressive stresses of complex helical & planetary gears using Lewes & Hertz equation, but also verifies the calculated specifications of the complex helical & planetary gears by evaluating the results with the data of allowable bending and compressive stress from the Stress - No. of cycles curves of gears. In addition, this paper explains actual gear scoring and evaluates the possibility of scoring failure of complex helical & planetary gear train of hydro-mechanical continuously variable transmission for the forklift.

Complex Trauma and Disorder of Extreme Stress(DESNOS) (복합외상과 극단적 스트레스 장애)

  • Park, Seon-Cheol;Kim, Seok-Hyeon
    • Anxiety and mood
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    • v.5 no.2
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    • pp.80-88
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    • 2009
  • Disorder of Extreme Stress, Not Otherwise Specified (DESNOS) is the proposed diagnosis that meets the severe, complex, and prolonged psychological sequela of victims with chronic traumatization (e.g., family violence, incest, and childhood sexual or physical abuse). The hallmarks of DESNOS are a multiplicity of symptoms (e.g., somatization, dissociation, and depression), pathological changes in relationships, identity disturbances, and a propensity to experience repeated harm and injury at the hands of oneself and others. DESNOS can be directly assessed by Structured Interview of Disorder of Extreme Stress (SIDES) and Self- Report Inventory of Disorder of Extreme Stress (SIDES-SR). The treatment of DESNOS should be phaseoriented and involve movement back and forth among three basic stages : 1) stabilization ; 2) trauma processing ; 3) reintegration.

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A Study on the Stress Distribution of Steel Water Pipes(II) - Characteristics of Stress Distribution by External Forces and PWHT - (상수도용 도복장간관의 용접 및 외부하중에 의한 응력 특성에 관한 연구(II) - 복합외부하중 및 후열처리에 따른 용접부의 응력분포 특성 -)

  • 윤석환;이승기;나석주;고명환
    • Journal of Welding and Joining
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    • v.19 no.3
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    • pp.292-297
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    • 2001
  • One of the major characteristics that affects the life of welded steel water pipes is the stress distribution caused by welding and external forces. Some studios have bean carried out on the residual stress of steel water pipes. But the results on the stress distributions by welding and complex external forces are rare, because real water pipes operate under the ground and many kinds of external forces act simultaneously on the joints. To understand the complex stress distributions of welded joints, therefore predictions by numerical or analytic methods are required. In this study, temperature and stress distributions in steel water pipes produced by welding are predicted by a three-dimensional finite element method(FEM). Based on these results, stress distributions by welding and complex external forces are evaluated by adopting the same numerical method. The influence of some post weld heat treatments on residual stress distributions is also investigated.

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Stress analysis of creep material containing elliptical rigid inclusion by complex pseudo-stress function (복소 유사응력함수에 의한 타원 강체함유물을 내포하는 크립재료의 응력해석)

  • Lee, Kang-Yong;Kim, Jong-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.2
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    • pp.408-415
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    • 1998
  • The analysis model is the power law creep material containing an elliptical rigid inclusion subjected to the arbitrarily directional stress on infinite boudary. The stress analysis is performed using the conformal mapping function and complex pseudo-stress function. The stress distributions near an elliptical rigid inclusion are obtained with various ellipse shapes, strain hardening exponents and directions of applied stress.

복소 유사 응력 함수에 의한 타원 강체 함유물을 내포하는 글잎 재료의 응력 해석

  • 김종성;이강용
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.740-743
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    • 1995
  • The analysis model is the power law creep material containing an elliptical rigid inclusion subjected to the arbitrarily directional stress on infinite boundary. The stress analysis is performed using the conformal mapping function and complex pseudo-stress function. The stress distributions near an elliptical rigid inclusion are obtained with various ellipse shapes, strain hardening exponents and directions of applied stress.

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The influence of complex traditional Korean medical treatment on the Peripheral Facial Paralysis induced stress (한방복합치료(韓方複合治療)가 STRESS로 유발된 말초성안면신경마비(末梢性顔面神經麻痺)에 미치는 영향)

  • Kim, Kyung-tae;Song, Ho-sueb
    • Journal of Acupuncture Research
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    • v.21 no.4
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    • pp.53-64
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    • 2004
  • Objective: This study was to evaluate the influence of stress on Peripheral Facial Paralysis during the complex traditional korean medical treatment. Methods: We investigated 41 cases of patients with Peripheral Facial Paralysis who were given the complex traditional korean medical treatment. one group had stress as main factor, the other group didn't it. we evaluated the treatment effect of each group by using Gross Grading System of House-Brackmann, Yanagihara's Unweighed Grading System. Results : 1. In age, sex, lesion, duration of disease, frequency of treatment, duration of treatment, we found that two groups have no significant differences. 2. Pain back of the ear showed the highest frequency in symptoms at onset. 3. Boyangwhanotang showed the highest frequency in oriental herb medicine treatment. 4. As a result of evaluation by using Gross Grading System of House-Brackmann, Yanagihara's Unweighed Grading System, treatment score after 2weeks was marked more higher than score before treatment and treatment score after final treatment was more higher than treatment score after 2weeks on each groups. 5. After final treatment, Non-stress group had signficant result on Gross Grading System of House-Brackmann, Yanagihara's Unweighed Grading System compared with stress group. Conclusion : These results suggested that patient with Non-stress group should be get better than stress group.

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Strength Evaluation of Complex Planetary Gear Train of Traveling Reducer for 1.7-Ton Grade Small Excavator (1.7톤급 소형 굴착기용 주행 감속기의 복합 유성기어류에 대한 강도 평가)

  • Nam, SeockJu;Bae, MyungHo;Cho, YonSang
    • Tribology and Lubricants
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    • v.38 no.1
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    • pp.22-26
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    • 2022
  • A 1.7-ton grade small excavator is a construction equipment that can perform various functions in limited spaces where heavy equipment cannot enter easily. Owing to the recent acceleration of urbanization, it has been used increasingly in drainage and gas pipes, as well as for road repair works in urban areas. The power train of a traveling reducer for a 1.7-ton grade small excavator utilizes a complex planetary gear system. Complex planetary gears are vital to the power train of a traveling reducer as it mitigates the fatigue strength problem. In the present study, the specifications of a complex planetary gear train are calculated; furthermore, the gear bending and compressive stresses of the complex planetary gears are analyzed to achieve an optimal design of the latter in terms of cost and reliability. In this study, the actual gear bending and compressive stresses of a planetary gear system are analyzed using a self-developed gear design program based on the Lewes and Hertz equation. Subsequently, the calculated specifications of the complex planetary gears are verified by evaluating the results with the data of allowable bending and compressive stress based on curves of stress vs. number of cycles of the gears.

Nonlinear response of complex fluids under LAOS(large amplitude oscillatory shear) flow

  • Ahn, Kyung-Hyun;Kyu Hyun;Nam, Jung-Gun;Manfred Wilhelm;Lee, Seung-Jong
    • Korea-Australia Rheology Journal
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    • v.15 no.2
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    • pp.97-105
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    • 2003
  • In the previous paper (Hyun et al.,2002), we have investigated the shape of storage modulus (G') and loss modulus (G") of complex fluids under large amplitude oscillatory shear (LAOS) flow. As the strain amplitude increases, owever, the stress curve becomes distorted and some important information may be smothered during data processing. Thus we need to investigate the stress data more precisely and systematically. In this work, we have obtained the stress data using high performance ADC (analog digital converting) card, and investigated the nonlinear response of complex fluids, 4wt% xanthan gum (XG), 2 wt% PVA/ 1 wt% Borax, and 1 wt% hyaluronic acid (HA) solutions, using Fourier transformation (FT) rheology. Comparing the strain signals in time domain with FT parameters in frequency domain, we could illustrate the sensitivity and importance of FT rheology. Diverse and unique stress patterns were observed depending on the material system as well as flow environment. It was found that they are not the outcome of experimental deficiency like wall slip but characteristics of the material system. When nonlinear response of complex fluids is analyzed, the intensity and phase angle of higher harmonic contributions should be considered together, and the shape of the stress signal was found to be strongly dependent upon phase angle.ngle.

Strength Analysis of Complex Gear Train for Transmission of 21-Ton Grade Wheel Excavator (21톤급 휠 굴착기용 트랜스미션의 기어 트레인에 대한 강도 해석)

  • Lee, JunHee;Bae, MyungHo;Cho, YonSang
    • Tribology and Lubricants
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    • v.38 no.5
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    • pp.179-184
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    • 2022
  • The power train of transmission for 21-ton grade wheel excavator makes use of a complex gear train composed of a planetary and helical gear system to drive the wheel excavator by transmitting power to the axle. The complex gear train with a shift mode is an important part of the transmission because of strength problems in an extreme environment. To calculate the specifications of the complex gear train and analyze the gear bending and compressive stresses of the complex gear train, this study analyzes gear bending and compressive stresses accurately for the optimal design of the complex gear train with respect to cost and reliability. In this article, the gear bending and compressive stresses of the complex gear train are calculated using the Lewes and Hertz equation. Evaluating the results with the data of the allowable bending and compressive stress from the stress and number of cycles curves of the gears verified the calculated specifications of the complex gear train. A computer structure analysis is performed with the 3D model of the planetary and helical gears to analyze the structure strength of the complex gear train. The results demonstrate that the durability and strength of the complex gear train are safe, because the safety factors of the bending and compressive stresses are more than 1.0.

Crack Opening Displacement Analysis of Complex Cracked Pipes based on Enhanced Reference Stress Method (개선된 참조응력법을 이용한 복합균열이 존재하는 배관의 균열개구변위 계산)

  • Huh, Nam-Su;Kim, Yun-Jae;Kim, Young-Jin
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.80-86
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    • 2001
  • An engineering estimation equation for the crack opening displacement (COD) is proposed for a complex cracked pipe, based on the reference stress approach. To define the reference stress, a simple plastic limit load analysis for the complex cracked pipe subjected to combined bending and tension is performed considering the crack closure effect in the compressive-stressed region. Comparison with ten published test data and the results from existing method shows that the present method not only reduces non-conservatism associated with the existing method, but also provides consistent and overall satisfactory results.

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