• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.271-276
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• 2018

When the driver riding in a bicycle goes on board, the load of driver is shown differently according to the position loaded on the frame of bicycle. The load is applied most at the joint of bike frame and the load at the mid-part of frame is applied least than the other parts. So, the weight of frame is decreased as the part not applied with a lot of load is manufactured into the thin thickness. As the part applied with high load is manufactured into the thick thickness, it can be endured through this load. The configurations of general frame, double butted and triple butted were modelled by using CATIA program. The durabilities of each model due to the load of passenger were investigated by carrying the structural and fatigue analyses. As this study result investigated with the analysis program of ANSYS, the deformation of general frame happened most and that of triple butted became least. These simulation analysis data are intended to be used to design the actual bicycle frame in the most efficient way at design and manufacture.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.1
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• pp.121-127
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• 2013

With the continuing demand for lightweight bicycles, carbon fiber composite materials have been widely used in manufacturing bicycle frames and components. Unlike general isotropic materials, the structural characteristics of composite materials are strongly influenced by the staking directions and sequences of composite laminates. Thus, to verify the design process of bicycles manufactured using composites, structural analysis is considered essential. In this study, a carbon-fiber-reinforced plastic (CFRP) bicycle frame was designed and its structural behavior was investigated using finite element analysis (FEA). By measuring the failure indices of the fiber and matrix under various stacking sequences and loading conditions, the effect of the stacking condition of composite laminates on the strength of the bicycle structure was examined. In addition, the structural safety of the bicycle frame can be enhanced by reinforcing weak regions prone to failure using additional composite laminates.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.147-156
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• 2016

In this paper, optimal designs of bicycle frame were studied for weight reduction of bicycle using carbon-fiber-reinforced plastic (CFRP), glass-fiber-reinforced plastic (GFRP) and Kevlar-fiber-reinforced plastic (KFRP), respectively. Based on the anisotropic properties of FRP material, stacking angle and thickness optimization were performed under the safety reference of European committee for standardization (CEN) to ensure the stability of bicycle frame. Finally, performances of FRP bicycle frame was evaluated by digital logic method based on the optimized results of weight, strength properties and cost. Then, the optimized bicycle frame composed of each FRPs were evaluated and ranked by total performance values.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.9
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• pp.1077-1082
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• 2013

To improve cycling performance, the power output of the rider and the sources of resistance (e.g., air resistance, frame stiffness, and cycle mass) must be considered. From a mechanical viewpoint, we consider how the bike frame performance can be increased while decreasing the resistance. First, to improve the competitive ability of a racing track cycle, we should consider the stiffness of the bike frame including the pedal loading and aerodynamic effects when riding. Therefore, we obtained the cross-sectional area of each part of the bike frame and then aimed to minimize the drag force through an aerodynamic parametric study. In addition, the frame should remain safe under the loading applied by the rider. Under the guidelines of the UCI (union Cycliste Internationale) regulations, the bike frame has been evaluated under the proposed loading condition, and we developed a racing track cycle for elite cyclists.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1011-1015
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• 2013

The demand of bike increases eco-friendly as the mean of transportation but domestic production basis becomes sluggish. In this study, the design analysis of horizontal and vertical frame is performed on the model which is proposed as the bike of new concept in conjunction with public transport system. As the result, the structural analysis is conducted on the main frame of urban bike used with cast magnesium alloy. As the vertical load of 150 kg is applied, the design technology insures that maximum stress less than 70 MPa is obtained.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.4
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• pp.178-185
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• 2017

Carbon fiber frames are actively developed for developing carbon fiber frames as the material of the next generation of bicycle frames, and are currently being developed with carbon fiber frames, hardness, shock absorption, light intensity, and strength. The carbon fiber bike models require a premium, differentiated design concept, which is essential to the development of a conceptual and differentiated design, requiring the development of essential structural structures, safety and refinement, and more of their own identity. In this study, a personal and unified image was derived from the research of the needs of consumers and image analysis process and then in the practical design work, the road bike bicycle frame design was proposed targeting the frame on the basis of carbon fiber materials.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.45-52
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• 2016

One commercial package for magnetic analysis was used to apply repulsive forces of permanent magnetics to bicycle cushion system. Reliabilities of finite element analysis were acquired by comparing with those of experimental measurements. Equivalent spring stiffnesses corresponding to various sizes of magnetics were implemented into the bicycle dynamic model with three degree of freedom. Input force caused at front and rear wheels due to road unevenness was considered in the dynamic model. Dynamic behaviors were observed in terms of vertical displacements of the rider and the front reach as well as pitching displacement of the mass center when the bicycle ran over half-triangular bump. The methodology suggested in this paper by the finite element analysis and numerical model will be an useful tool for more accurate prediction of cushion design for any vehicle system if magnetic forces are utilized.

• Composites Research
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• v.29 no.6
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• pp.358-362
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• 2016

Mechanical properties of static and dynamic behavior became important since the use of conical composite tubes in large structures such as aerospace, planes, and submarines as well as leisure goods such as bicycle frames, fishing rods, and golf shafts. In the past, the mechanical property prediction model for static behavior was studied using vibration, bending, and buckling. But there is a need to study how fiber orientation error affects mechanical properties of conical composite structure because the model assumes constant fiber orientation angle. The purpose of this study is to derive an equation that can predict the static behavior of conical composite tube for bicycle frames by considering fiber orientation error with respect to various design parameters.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.122-129
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• 2012

This study investigates structural and vibration analyses according to the thickness of bicycle frame tube. The model of bicycle frame has the dimension as length of 862mm, width of 100mm and hight of 402.5mm. There are 3 kinds of models with tubes of top, down and seat at bicycle frame as thicknesses of 10, 15 and 20mm. The maximum displacement and stress occur at the center part of seat stay and at the installation part of rear wheel respectively. Maximum displacements become 0.031936, 0.029159 and 0.027984mm in cases of thicknesses of 10, 15 and 20mm respectively. In case of thickness of 20mm among 3 cases, maximum displacement becomes lowest. But maximum stresses become 10.019, 8.5492 and 9.2511MPa in cases of thicknesses of 10, 15 and 20mm respectively. In case of thickness of 15mm among 3 cases, maximum stress becomes lowest. There is no resonance at practical driving conditions and natural frequency remains almost unchanged along the change of thickness. In case of the displacement due to vibration mode, the displacement difference at thickness between 15mm and 20mm becomes 1/2 times than that between 10mm and 15mm. Design at bicycle frame tube becomes most economical and durable effectively in case of thickness of 15mm among 3 cases.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.208-208
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• 2012

최근 환경문제가 많이 제기되면서 친환경적 운송수단인 자전거 개발과 관련하여 다양한 기술개발이 이루어지고 있다. 그 중 고부가가치의 서스펜션 포크의 프레임에 고기능성 표면처리로 Arc ion plating deposition system (AIPDS)을 이용하여 부식, 내마모 특성이 뛰어난 TiN 박막을 증착시켰다. AIPDS는 기존의 arc system과 달리 다원계 소재 코팅 공정조건 확립을 위하여 chamber wall에 2개의 rectangular type sputter source를 장착하고 소재의 pre-treatment 용 linear type ion source를 설치하였다. 장비의 Chamber 중앙에는 pipe형 arc cathode를 설치하였으며, 그 주위를 anode 역할을 하는 copper 코일로 감아 이는 발생한 arc를 target인 cathode 축을 중심으로 방향성을 가지고 회전하여 진행 할 수 있도록 유도 하였다. 이 시스템에서 증착된 TiN 박막은 bias 전압 변화에 따른 박막의 구조 및 물성을 평가하였다. XRD 장비를 통하여 TiN 박막의 상분석을 진행하였고, 마모테스터, 원자현미경, 마이크로 비커스 경도기 등을 이용하여 기계적 특성을 평가하였다.