• Elastomers and Composites
• /
• 제38권3호
• /
• pp.206-212
• /
• 2003

본 논문에서는 인솔에 coolant가 있는 골프화에 대해서 이론적인 해석방법과 설계기술을 연구하였다. 골프화를 구성하고 있는 인솔의 형상과 미드솔, 아웃솔을 고려하여 유한요소법으로 모델링하였다. 열전달을 위한 유한요소의 경계조건으로는 인간발의 표준적인 온도가 사용되었다. 열전달해석을 위해 상용프로그램으로는 MARC V7.3를 사용하였고 온도 및 인솔의 열전도량을 구했다. 본 연구에서 열전달의 특성에 따라서 유한요소법의 결과가 다르게 나온다는 결론을 얻었다. 본 연구 결과는 골프화 해석에 보다 나은 이해를 제공해준다. 더욱이, 본 연구결과는 골프화 관련 업체에서 활용할 경우 보다 효과적으로 설계하도록 도울 것이라고 믿는다.

• Structural Engineering and Mechanics
• /
• 제86권6호
• /
• pp.715-730
• /
• 2023

Broad studies have addressed the issue of structural element damage identification, however, rubber bearing, as a key component of load transmission between the superstructure and substructure, is essential to the operational safety of a bridge, which should be paid more attention to its health condition. However, regarding the limitations of the traditional bearing damage detection methods as well as few studies have been conducted on this topic, in this paper, inspired by the model updating-based structural damage identification, a two-stage bearing damage identification method has been proposed. In the first stage, we deduce a novel bearing damage localization indicator, called element relative MSE, to accurately determine the bearing damage location. In the second one, the prior knowledge of bearing damage localization is combined with sailfish optimization (SFO) to perform the bearing damage estimation. In order to validate the feasibility, a numerical example of a 5-span continuous beam is introduced, also the noise robustness has been investigated. Meanwhile, the effectiveness and engineering applicability are further verified based on an experimental simply supported beam and actual engineering of the I-40 Bridge. The obtained results are good, which indicate that the proposed method is not only suitable for simple structures but also can accurately locate the bearing damage site and identify its severity for complex structure. To summarize, the proposed method provides a good guideline for the issue of bridge bearing detection, which could be used to reduce the difficulty of the traditional bearing failure detection approach, further saving labor costs and economic expenses.

• Earthquakes and Structures
• /
• 제5권4호
• /
• pp.477-497
• /
• 2013

This paper reports extensive experimental study done to compare workability and bond strength of five different types of polymer-based bonding agents for reinforcing bars in pinning retrofit. In pinning retrofit, steel pins of 6 to 10 mm diameters are inserted into holes drilled diagonally from mortar joints. This technique is superior to other techniques especially in retrofitting historic masonry constructions because it does not change the appearance of constructions. With an ordinary cement paste as bonding agent, it is very difficult to insert reinforcing bars at larger open times due to poor workability and very thin clearance available. Here, open time represents the time interval between the injection of bonding agent and the insertion of reinforcing bars. Use of polymer-cement paste (PCP), as bonding agent, is proposed in this study, with investigation on workability and bond strengths of various PCPs in brick masonry, at open times up to 10 minutes, which is unavoidable in practice. Corresponding nonlinear finite element models are developed to simulate the experimental observations. From the experimental and analytical study, the Styrene-Butadiene Rubber polymer-cement paste (SBR-PCP) with prior pretreatments of drilled holes showed strong bond with minimum strength variation at larger open times.

• Smart Structures and Systems
• /
• 제16권6호
• /
• pp.1023-1047
• /
• 2015

In this study, the optimal location of the MR fluid segments in a partially treated laminated composite sandwich plate has been identified to maximize the natural frequencies and the loss factors. The finite element formulation is used to derive the governing differential equations of motion for a partially treated laminated composite sandwich plate embedded with MR fluid and rubber material as the core layer and laminated composite plate as the face layers. An optimization problem is formulated and solved by combining finite element analysis (FEA) and genetic algorithm (GA) to obtain the optimal locations to yield maximum natural frequency and loss factor corresponding to first five modes of flexural vibration of the sandwich plate with various combinations of weighting factors under various boundary conditions. The proposed methodology is validated by comparing the natural frequencies evaluated at optimal locations of MR fluid pockets identified through GA coupled with FEA and the experimental measurements. The converged results suggest that the optimal location of MR fluid pockets is strongly influenced not only by the boundary conditions and modes of vibrations but also by the objectives of maximization of natural frequency and loss factors either individually or combined. The optimal layout could be useful to apply the MR fluid pockets at critical components of large structure to realize more efficient and compact vibration control mechanism with variable damping.

• 한국해양공학회지
• /
• 제17권4호
• /
• pp.37-42
• /
• 2003

The mechanical components with high-pressure hoses are generally produced by the swaging process. The hoses are composed of the rubber materials and the reinforced braids to support tensile forces. In case they are subjected to high mechanical and thermal loads under severe operating conditions, the oil in hoses can leak at the parts of small clamping forces. In this paper, the deformation characteristics of a fiber-reinforced hose are analyzed with respect to the jaw strokes using the finite element method. The manufacturing process is modeled with a contact problem in consideration of a real situation, and the material properties based on the experimental results are used in the analysis. Examinations of the relationship between the swaging strokes and the deformation behaviors of the hose were made on the basis of the stress and strain values of the hose components. The relations between clamping forces and separating forces are also proposed, in order to estimate clamping forces corresponding to separating forces for the given model.

• 한국기계가공학회지
• /
• 제10권3호
• /
• pp.39-46
• /
• 2011

The automotive air conditioning hose is used for connecting the components of air conditioner in a vehicle. The hose is usually manufactured by the swaging process to connect the rubber hose with the metal fitting at the end of the hose. In case that the clamping force is small, the refrigerant gas in the hose can leak locally under the severe operating circumstances. The practical test of clamping force is performed by means of the measurement of separation force. In this study, the swaging process of a hose is simulated with the finite element method, to investigate the effect of friction coefficient on the clamping force. The contact condition is used in consideration of real manufacturing process, and the material properties for the Mooney-Rivlin model is obtained by the experimental results. The result interpretations are focused on the contact forces, which is displayed graphically with respect to friction coefficient, on the surfaces between the hose and the metal fittings.

• Structural Monitoring and Maintenance
• /
• 제5권1호
• /
• pp.39-50
• /
• 2018

Taking three types of bridge bearings with diameter being 100 mm as examples, the theoretical analysis, the experimental research as well as the numerical simulation of these bearings is conducted. Since the normal compression and shear machines cannot be applied to the small-size bearings, an improved equipment to test the properties of these bearings is proposed and fabricated. Besides, the simulation of the bearings is conducted based on the explicit finite element software ANSYS/LS-DYNA, and some parameters of the bearings are modified in the finite element model to reduce the computation cost effectively. Results show that all the research methods are capable of revealing the fundamental properties of the small-size bearings, and a combined use of these methods can better catch both the integral properties and the inner detailed mechanical behaviors of the bearings.

• Tribology and Lubricants
• /
• 제25권2호
• /
• pp.120-124
• /
• 2009

In automobile chassis system, several environmental factors weaken durability of automobile's components. The environmental factors are temperature, humidity, intensity of radiation and dust particle inflow. Especially, dust particle inflow leads to increase in friction and wear of automobile's components. The wear of automobile's component leads to increase in noise and exerts a bad influence on life of components. In this study, dust particles were investigated for study on the influence of dust particle inflow. Dust particles are collected on urban area, rural area and highway in China. The size of dust particle is analyzed using the image plus program, and the element of dust particle is analyzed using the SEM and EDX. The elements of dust particle are $SiO_2$ and $Al_{2}O_{3}$. The other elements(Na, Ca, Cl etc..) are detected on urban area and highway.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 춘계학술대회논문집
• /
• pp.622-625
• /
• 2008

SIL-based optical disk drive will be promising candidate of next-generation storage devices. However, a near-field optical disk drive requires the robustness to external shock because of extremely small gap between SIL and media. Especially, high-level shock damages permanently to SIL and it makes difficulties in general application. To study the likelihood of failure, the shock analysis must be performed over all others. This research explores the dynamic characteristics of rotating disk through FEM which is compared to analytical solution and experimental modal analysis. We also develop the finite element model of an optical disk drive, which includes rubber mounts, sled base, rotating disk and pickup assembly, and simulate the shock response.

• Tribology and Lubricants
• /
• 제28권6호
• /
• pp.283-288
• /
• 2012

In this study, a new sliding contact problem involving an elastomeric seal, a spherical particle and a hard coated steel counterface was modeled to investigate the detailed wear mechanisms related to the sealing surface. The model was also used to design the optimum coating conditions. A three-dimensional finite element contact problem was modeled and analyzed using the nonlinear finite element code, MARC. The deformed steel surface and stress distributions are presented for different coating layers and thicknesses. When the coating thickness is relatively small, the entrapped particle produces surface plastic deformations such as groove and torus. In addition, the sealing surface can be damaged by abrasive wear as well as fatigue wear. For a relatively thick and multi-layered coating, on the other hand, surface plastic deformation does not occur, and the amount of abrasive and fatigue wear is reduced. Therefore, the proposed contact model and results can be used in the design of various sealing systems, further intensive studies are required.