• Title/Summary/Keyword: 체결력

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Optimum Design of Lock Snap-fit Using Design of Experiment (실험계획법을 이용한 이탈방지 스냅핏의 최적설계)

  • Son, In-Seo;Shin, Dong-Kil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.8
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    • pp.378-385
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    • 2017
  • This study investigated the design of a snap fit, which is widely used for fastening plastic parts. We analyzed the assembly mechanism of a lock snapfit, measured the assembly force and separation force based on the design of experiments, and derived a regression equation through an analysis of variance. The response surface methodology was also used. Polybutylene terephthalate was used to fabricate specimens, and the assembly force and separation force were measured using a micro-tensile tester. The length, width, thickness, and interference were considered as factors. A second-order regression model was used to derive the regression equation. The assembly force decreased with increasing length and width, but it increased with increasing thickness and interference. The finite element method was used to analyze the assembly mechanics. The width decreased the assembly force by increasing the ductility. The influences of the factors for low assembly force and high release force were shown to be opposite to each other. It was necessary to design a structure that minimized the assembly force while maintaining an appropriate level of separation force.

Simplified Finite Element Model of an Anchor Bolt Inserted Through Concretes Considering Clamping Forces (체결력을 고려한 콘크리트 삽입 앵커볼트의 간편 유한요소 모델)

  • Noh, Myung Hyun;Lee, Sang Youl;Park, Kyu Sik
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.4
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    • pp.293-300
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    • 2013
  • In this study we proposed a simplified finite element model of anchor bolt system inserted through concrete structures considering clamping forces. The three different finite element types using LS-DYNA are applied for numerical efficiency of the anchor bolt modeling. Combined beam and solid elements are used to reflect the tension state at internal part of anchor bolt due to torques. The clamping forces due to torques are considered by introducing a compression for a nut plane modeled by beam elements. The numerical examples show good agreement with different element types. Parametric studies are focused on the various effects of different element types on the induced axial and shear forces of anchor bolts considering clamping forces.

Influence of Initial Clamping Force of Tension Clamp on Performance of Elastic Rail Fastening System (텐션클램프의 초기 체결력이 탄성레일체결장치의 성능에 미치는 영향)

  • Lee, Dong Wook;Choi, Jung Youl;Baik, Chan Ho;Park, Yong Gul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.3
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    • pp.1243-1251
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    • 2013
  • The purpose of this study is to investigate the influence of initial clamping force of tension clamp on the performance of an elastic rail fastening system used in sharp curve track. In this study, the initial clamping force and the increasing lateral wheel loads were conducted in the analytical and experimental study, i.e., finite element analysis, laboratory and field test. Using the analytical and experimental results, the performance of the tension clamp was investigated. It was found that the stress of tension clamp depends on the initial clamping force. Therefore the initial clamping force appeared to directly affect the compression stress of the tension clamp. It was found that the compression stress of tension clamp was transferred to the tensile stress by applied the lateral wheel load in service sharp curve track. Further, it was concluded that the initial clamping force was applied on the strengthening force for the tension clamp and then the appropriate initial clamping force was important to ensure a stable performance and long term endurance of tension clamp.

Study on The Suggested Curve Fitting Algorithm for Bolt Clamping Force Measurement (볼트 체결력 측정을 위해 제안한 커브피팅 알고리즘에 관한 연구)

  • Lee, Ki-Won
    • Journal of Satellite, Information and Communications
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    • v.7 no.3
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    • pp.94-98
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    • 2012
  • In order to serve the exact torque clamping force, the torque measurement system use the curve fitting algorithm by the least square. The corrected least square curve fitting algorithm which suggested in this paper can surpport more exact clamping force for fastner in variable industry field using the torque. At first, This paper introduces mathematical modeling for curve fitting algorithm, and simulate it. As a result, the corrected least square algorithm have shown lower standard error value than that of the used algoritm with torque, and so this corrected least square algorithm prove high accuracy than nomal least square algorithm. The suggested algorithm will contribute to improvement of cost and safety on industry field with bolt clamping force for precision industry parts, electronics parts, aircraft, aerospace, etc.

Structural Analysis of High Precision Reflector Using Finite Element Analysis (유한요소해석법을 이용한 고정밀 반사경의 구조 해석)

  • Lee, Sang-Yong;Kim, Ghiseok;Kim, Geon-Hee;Lee, Young-Shin
    • Journal of the Korean Society for Nondestructive Testing
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    • v.33 no.2
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    • pp.154-159
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    • 2013
  • In this paper, the effect of bolt clamping force and form accuray of contact surface between mirror and mount on mirror surface was studied. Normally, mirror used in reflecting optical system was assembled with mount by bolts or adhesive. In this case, the tension caused by bolt clamping force or adhesive force may distort the mirror surface. Also, form accuracy error of the contact surface have a negative impact on wrenched mirror surface which assembled by bolts or adhesive. In this study, stress and distorted displacements on mirror surface were analyzed according to the different contact surface form accuracies and bolt clamping forces by using the finite element analysis method.

A Study on The Change of Insert Clamping Force Influence According to the Surface Treatment of Armor Aluminum Alloy Plate (장갑판재의 표면처리에 따른 인서트 체결력 변화 연구)

  • Hwang, Bu Il;Yang, Sang Hun;Kim, Chi Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.8
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    • pp.787-791
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    • 2015
  • In some cases which are unable to replace the inserts when the depot maintenance or performance improvement of armored vehicles are carried out could have a risk of declining clamping forces by re-processing chromate. The change in the clamping forces of inserts has been investigated by applying a chromate process to hold the insert on the aluminum plate of the armored vehicle in this paper. In order to identify the effect of types and surface treatment, the breaking strength has been measured by the equivalent test item to the actual conditions. These tests would contribute the establishment of the armored vehicle production process.

Estimation of Contact Stress Distribution Factor in Bolt Joint with variable Fastening torque (체결력에 따른 볼트 결합부의 접촉응력분포계수 평가)

  • 김종규
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.2
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    • pp.73-79
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    • 1999
  • Most of mechanical structures are combined of substructures such as beams and/or plates. There are few systems with unibody structures but are many systems with united body structures. Generally the dynamic a nalysis of whole structures is performed under alternation load. In the structure design, the analysis of each bolted joint is more important than others for zero severity. This paper presents the analysis method of contact stress distribution factor in the bolted joint with variable fastening torque on joints in the structure. At first, a static vibration test was performed to find out a nominal stress of bolt jointed plates from the relationship between natural frequency and nominal stress. Then a contact stress was computed at contact point between bolt and plate in the structure. It is believed that the proposed method has promisiong implications for safer design with index of contact stress distribution factor and has merits for cost-down and saving time at the beginning of vehicle development.

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An Experimental Study of Vibrator Amplitude Change for a Clamping Force Dispersion and Friction Coefficient Decrease (체결력 산포와 마찰계수의 감소를 위한 가진기의 진동량 변화 실험)

  • Lee, Geum-Gang;Moon, Seok-Man;Cho, Yong-Joo
    • Tribology and Lubricants
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    • v.27 no.6
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    • pp.332-337
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    • 2011
  • The object of this experimental study is to investigate influences of vibrator amplitude on clamping force in vibration for bolted joint. The experiment is that change the vibrator amplitude to check clamping force. also the friction coefficient calculated by equation to use an obtained in experiments. The main purpose of generation vibrations is decreasing the clamping force dispersion. also If vibration occurs while tightening the bolt is reduced coefficient of friction. In this paper, In experiments to measure the clamping force before vibrator's amplitude changing. Vibrator's amplitude changes to 5.5mm from 4.4mm. As a result, under various vibration condition, relationship of clamping force and Vibrator amplitude.

Estimation of stress concentration factor in bolt jointed structure with variable preload (체결력에 따른 볼트 결합구조물의 응력집중계수 평가)

  • 송준혁
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • pp.298-303
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    • 1998
  • Most of mechanical structures are combined of substructures such as beam and/or plates. There are few system with unibody structures but are not a few systems with united body structures. Generally the dynamic analysis of whole structures is perform ed under alternating load. However, the analysis of each joint area is more important than others for zero severity. This paper presents the results of analysis of concentration stress in bolt jointed structure with variable preload. At frist, a static vibration test was performed to find out a nominal stress of bolt joint ed plates from the relationship between natural frequency and nominal stress. Then a concentration stress was computed at contact point between bolt and plate in the structure. It is believed that the proposed method has promising implications for safer design with fatigue quality index of stress concentration factor and has merit for cost down and saving time at the beginning of vehicle development.

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Improvement of Connection Force in Hydro-Embedding Process Through the Rotational Piercing of the Connection Element (하이드로 임베딩시 연결요소의 회전을 통한 체결력 개선 연구)

  • Kim, Bong-Joon;Kim, Dong-Kyu;Kim, Dong-Jin;Moon, Young-Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.12
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    • pp.1503-1508
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    • 2006
  • To increase the applicability and productivity of hydroforming process, hydro-embedding process was developed by combining the hydro-forming process with embedding process simultaneously. It is necessary in the automotive parts to form hollow bodies with connection elements which combine one part with another. The hydro-embedding process is embedding the connection element hydraulically during the operating steps of the hydroforming. In this study, technique of rotational piercing is added on the existing hydro-embedding to increase the connection force of hydro-embedded element. To estimate the feasibility of new trial process, integrated researches on the hydro-embedding process technology have been performed by analyzing the deformed mode of the tubes and the optimal process parameters for various shapes of the connection elements.