• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.677-680
• /
• 2004

This study investigates the buckling evaluation of connecting rods used in the diesel engine through finite element analysis. The Rankine formula, which is modified from classical Euler‘s formula, has been widely accepted in automotive industry to evaluate the buckling of connecting rods. Apparently, this formula is most suitable for the straight and idealized rod shape, and over-simplifies the geometric complexity associated with connecting rods. The subspace iteration method in FEA is used to predict the critical buckling stress of a connecting rod with certain slenderness ratio. To create models with various slenderness ratios for shank portion in the rod, the automatic meshing preprocessor was implemented. Results from FEA were verified by the experiments, in which the embedded strain gages measured for the connecting rod running at 4000rpm. The result indicates that the buckling prediction curve through FEA and experiment is effectively different from the curve of classical Rankine formula.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.24 no.6
• /
• pp.716-723
• /
• 2016

A connecting rod is a crucial part for transmitting an explosive force to the crankshaft in the engine. Stress concentration in connecting rod due to the accumulation of the repeated load may initiate micro crack and result in a crucial break down of the component. Two approaches are adopted to obtain a robust design of connecting rod. Inner and outer array matrix based on combinations of control factors and noise factors are constructed for using Taguchi method. Calculated stress results for each element of matrix are plotted in the Goodman diagram. Robust design approach by Taguchi method reduces stress concentration occurred in small end fillet area of the default model. Variable stress approach using Goodman diagram also confirms a robust design by Taguchi method.

• Transactions of Materials Processing
• /
• v.6 no.5
• /
• pp.435-445
• /
• 1997

In order to study the manufacturing possibility of connecting rod by direct quenching method, the difference between connecting rod by direct quenching and that by general heat treatment were investigated by observing microstructure, by measuring mechanical properties, by conducting fatigue testing, and by measuring the amount of tool wear in actual cutting. Connecting rod manufactured by direct quenching had better fatigue life than that by general heat treatment, which was due to homogeneous microstructure, and higher strength. The amount of cutting tool wear of connecting rod by direct quenching was higher than that by general heat treatment, which was due to low machinability and high toughness of tempered martensite microstructure. Therefore it will be added the study of heat treatment and cutting condition for manufacturing by direct quenching.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.12 no.4
• /
• pp.137-147
• /
• 2010

This study set out to make experimental clothes by giving variations to the connecting part of a seamless sweater, propose designs and composition approaches to improve the wearing sensation and satisfaction with appearance through wearing trials, and provide basic data that would be of practical help to follow-up study on seamless knit and the growth of seamless knit in the Korean knit industry. The connecting part is the biggest characteristic and the most important part in seamless knitwear and affect the functionality and fitness of the clothes and the appearance of the armhole. The investigator thus made five different pieces of experimental clothes according to the composition methods for connecting part and put them to the test by a group of experts for appearance assessment. The assessment results were analyzed through Analysis of variance(ANOVA), and the items with similar results were put to the Duncan test for intergroup comparison. According to the analysis results, experimental clothes C and E received the highest evaluation in almost every assessment item, whereas experimental clothes A did the lowest appearance evaluation.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.2
• /
• pp.382-390
• /
• 1995

Failure of connecting rod in automotive engine may cause catastrophic situation. The corner radius at small end has an effect on stress raising. To investigate the stress distribution in connecting rod during operation, the finite element analysis was used by giving possible maximum tension and compression. Excessive sizing after forging connecting rod may result in the tensile residual stress which lower the fatigue life and cause premature failures. It was shown that when the sizing amount is too large, the location of high tensile residual stress coincide with that of high stress amplitude during operation through the elastic-plastic finite element analysis. The endurance limit moves down due to the surface finish and decarburization, which combines with the movement of resultant stress points to dangerous range. It was concluded that the precise control of sizing and enough corner radius are necessary to a reliability of connecting rod.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.4
• /
• pp.14-20
• /
• 2008

Fatigue fracture of engine connecting-rod bolts is encountered frequently during the developement of high-speed engines. Only the engine dyno test is a currently reliable fatigue durability assessment method. It is because the available rig tests cannot mimic the engine running condition completely, and because the finite element analysis cannot provide realistic stresses near the bolt thread that is modeled as a cylinder. This paper introduces a methodology to assess the fatigue durability of the connecting-rod bolts using the finite element analysis. The methods to contruct the bolt model, to extract the critical bolt stresses for the fatigue analysis, and to obtain the bolt fatigue endurance limit experimentally are discussed. Reliability of the method is verified indirectly.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1997.04a
• /
• pp.183-189
• /
• 1997

This paper presents the motion of dynamically loaded journal in the connecting rod bearing of reciprocating internal combustion engine. Journal motions in engine bearings have been composed of two components, which was rotational and translational motion. Early study of journal locus in engine bearing had been performed on each motion. This paper has been considered two motions simultaneously. Reynolds equation including the squeeze effect has been analyzed using the ADI method, and real engine bearing and crankshaft system has been considered to calculate the cyclic external force. The equations of journal motion have been derived and then the numerical integration of these equations performed by 4th order Runge-Kutta method. This paper gives various journal orbits in connecting rod bearing depending on cyclic external forces, rotating speeds, and bearing parameters.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.4
• /
• pp.17-23
• /
• 1998

This paper presents the motion of dynamically loaded journal in the connecting rod bearing of reciprocation internal combustion engine. Journal motions in engine bearings have been composed of two components, which was rotational and translational motion. Early study of journal locus in engine bearing had been performed on each motion. This paper has been considered two motions simultaneously. Reynolds equation including the squeeze effect has been analyzed using the ADI method, and real engine bearing and crankshaft system has been considered to calculate the cyclic external force. The equations are performed by 4th order Runge-Kutta method. This paper gives various journal orbits in connecting rod bearing depending on cyclic external forces, rotation speeds, and bearing parameters.

• Structural Engineering and Mechanics
• /
• v.10 no.3
• /
• pp.263-275
• /
• 2000

In this paper, a core wall structure coupled with connecting beams is discretized and modeled as an equivalent thin-walled member with closed section, while the connecting beams between openings are replaced by an equivalent shear diaphragm. Then, a numerical method (finite member element method, FMEM) for dynamic analysis of the core wall structure is proposed. The numerical method combines the advantages of the FMEM and Vlasov's thin-walled beam theory and the effects of torsion, warping and, especially, the shearing strains in the middle surface of the walls are considered. The results presented in this paper are very promising compared with the ones obtained from finite element method.

• International Journal of Advanced Culture Technology
• /
• v.10 no.2
• /
• pp.194-200
• /
• 2022

Traditionally, postal services that produce and deliver paper-based notices have been the mainstream. The reason is that it has the function of distribution and proof of delivery in the postal delivery system as well as the advantage of information delivery through postal delivery. After all, for the purpose of distribution and proof of delivery, many organizations use paper-based postal notices. However, in recent years, it has been in the spotlight to produce a paper-based postal notice as an electronic notice and deliver information to a mobile device through the Internet. In this paper, we propose a safe interworking method for user identification information required for private institutions to transmit mobile electronic notices. In order for a private institution to accurately deliver an electronic notice to a mobile service subscriber, a means to confirm whether the private institution and the mobile device subscriber are the same person is required. In the mobile electronic notification service, the connecting information provided by the personal identity proofing agency is used as a means of user identification. Connecting information is called a resident registration number on the Internet and is one-way hash information that can only be created by the personal identity proofing agency designated by the government. In order to transmit a mobile electronic notice, it is necessary to share connecting information for the same user identification between the institution that requests the sending of the electronic notice and the institution that processes the sending of the electronic notice. Connecting information is personal information that can uniquely identify a user, and if it is disclosed, damage such as personal information infringement may occur. As such, it is necessary to prevent problems that may arise from misuse and abuse of connecting information as well as increase in the benefits of sending the mobile electronic notice. In this paper, a safe and effective mobile electronic notification service can be performed by suggesting a method for safe interworking of information related to the mobile electronic notification service.