• 한국공작기계학회논문집
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• 제13권2호
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• pp.9-16
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• 2004

Because a generated heat during grinding operation makes a serious deformation on a ground surface as a convex form, a real depth of cut in deformed zone has larger than an ideal depth of cut. Consequently, the ground surface has a geometric error as a concave form after cooling the workpiece. In this study, the force and the geometric error of surface grinding were examined. From evaluating magnitude and mode of the geometric error according to grinding conditions, an optimal grinding condition was proposed to minimize the geometric error. In addiction the relationship between the geometric error and the grinding force was found out. Due to least square regression it was able to predict the geometric error by using the grinding force.

• 한국구조물진단유지관리공학회 논문집
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• 제11권6호
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• pp.159-168
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• 2007

장대레일에 발생되는 축력은 좌굴 혹은 파단 등과 같은 사고의 예방에 있어서 매우 중요한 요소이므로 많은 철도 기술자들은 장대레일에 발생되는 축력 산정에 많은 관심을 나타내고 있다. 본 논문에서는 장대레일에 발생되는 축력을 추정하기 위한 보-기둥 이론의 적용성을 고찰하였으며 축력을 추정하는 방정식과 모델의 개발 과정을 제안하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.972-977
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• 2009

For the improvement of a train speed in the conventional line from overhead system point of view, it is necessary to approach not only in the aspect of the increasement of tension for catenary but the application of a pre-sag. A certain tension acting on a dropper is removed when it is slack by the pantograph passing. Right after the pantograph passes, the dynamic force caused by the mass of contact wire acts on the dropper. If the pre-sag is applied to the catenary, the static force on the dropper is increased. For the assurance of the safety for the dropper, it is necessary to predict the dynamic force. The purpose of this study is to predict and analyze the force on the dropper according to the applied pre-sag.

• 소성∙가공
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• 제28권4호
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• pp.190-196
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• 2019

The capability of accurately predicting the roll force profile across a strip in the bite zone in cold rolling process is vital for the calculation of strip profile. This paper presents a derivation of a precision mathematical model for predicting variations in the roll force across a strip in cold rolling. While the derivation is based on an approximate 3-D theory of rolling, this mathematical model also considers plastic deformation in the pre-deformation region which is located close to the roll entrance before the strip enters the bite zone. Finally, the mathematical model is expressed as a boundary value problem, and it predicts the roll force profile and tension profile in addition to lateral plastic strain profile.

• 한국정밀공학회지
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• 제14권2호
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• pp.169-177
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• 1997

In this study, investigated are the effects of tool rake angles and the change of cutting conditions on the specific cutting pressure in face milling. The cutting force in face milling is predicted from the double cutting edge model in3-dimensional cutting. Conventional specific cutting pressure model is modified by considering the variation of tool rake angles. Effectiveness of the modified cutting force model is verified by the experiments using special face milling cutters with different cutter pockets and various rake angles. From the comparison of the presented model and the specific cutting pressure, it is shown that the axial force can be predicted by the tangential force, radial force and geometric conditions. Also, the rela- tionship between specific cutting pressure and cutting conditions including feedrate, cutting velocity and depth of cut is studied.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.564-567
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• 1997

In the design of structure the forces acting on the structure are important parameter for noise and vibration control. However, in the complex structure, the forces at the injection point on the structure cannot be measured directly. Thus it is necessary to find out indirect force evaluation method. In this paper forces have been measured with in-situ vibration responses and system information. Three existing techniques of indirect force measurement, viz. direct inverse, principal component analysis and regularization have been compared. It has been shown that multi-vibration responses are essential for the precise estimation of the forces. To satisfy those conditions, Rotary compressor is adopted as test sample, because it is very difficult to measure the injection forces from internal excitation to shell. It has also been obtained that relatively higher force is transmitted though three welding paths to the compressor shell. It shows a good agreement between direct and indirect force evaluation with curvature shell and plate and is investigated the possibility of force evaluation of rotary compressor as a complex structure.

• 한국생산제조학회지
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• 제8권4호
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• pp.87-92
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• 1999

Generally the life of die is limited by fatigue fracture or dimensional inaccuracy originated from wear. In this paper to predict the fatigue life of die the stress and strain histories of die can be predicted by the analysis of elastic-plastic finite element method and the elastic analysis of die during the process analysis of workpiece. Also the stress-life curve of die material can be obtained through experiment. With the above to재 facts we propose the analysis method of prediction fatigue life in die,. In the proposed model the analysis of elastic-plastic finite element method for material is carried out by using ABAQUS. Surface force resulted from the contacting border of the die and workpiece is transformed into the nodal force of die to implement elastic analysis. besides the proposed analysis model of die is applied to extrusion die and forging. die.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.1018-1022
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• 2000

Enhancement of the accuracy of products and productivity are essential to survive in a global industrial competition. This trend requires tighter dimensional tolerance specifications. To actively cope with the rapid change of the workpiece material and cutter geometry, a general method that can predict and analyze the machined surface is needed. Surface generation model for the prediction of the topography of machined surfaces is developed based on cutting force model considering cutter deflection and runout. This paper presents the method that constructs the three-dimensional machined surface error following the movement of a cutter, irrespective of the variations of cutting conditions. In addition, the effects of the cutting forces and the kink shape on the machined surface are extensively investigated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.721-724
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• 2000

This paper presents a prediction of tool deflection and resulting machining error fur sculptured surface productions in the ball-end milling process. Due to the different materials and the dimensions of the tool holder and cutter, a cantilever hem model with three uniform sections is proposed fur the tool deflection model. The ability of this model has been verified by a machining experiment. In this study, cutting force and machining error are investigated. This paper provides the prediction of machining error for sculptured surface to improve machining quality for industrial application.

• 대한기계학회논문집
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• 제17권12호
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• pp.3045-3054
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• 1993

The mechanics related with piston-slap induced vibration has been studied in terms of non-dimensionalized dynamic equation of motion, various non-dimensional parameters such as non-dimensional side-thrust force and non-dimensional impact velocity throughout the numerical simulation. Experimental verification on the suggested prediction method has been also performed by using single cylinder engine which was carefully designed and manufactured to wisely control the engine parameters, especially clearance and the mass of piston. The predicted and experimentally observed vibration signature confirm that the proposed method is practically useful.