• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.124-125
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• 2019

The use of road cutters in the maintenance of obsolete underground facilities maintains polluting dust, cutting sludge, etc, polluting the air environment, soil, and water, causing civil complaints caused by noise, and consequently interrupting work. Therefore, it is time for eco-friendly pavement cutting technology for fugitive dust and cutting sludge emission management and noise management. This study was based on research by the development of eco-friendly pavement cutting technology in urban areas. In this study, the current state of existing road cutters is investigated and the patented technology analysis of road cutters is conducted to derive the design elements of eco-friendly pavement cutting technology.

• 대한기계학회논문집A
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• 제22권1호
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• pp.1-15
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• 1998

In this paper, thermo-viscoplastic finite element analysis of the effect of tool edge radius on cutting process are performed. The thermo-viscoplastic cutting model is capable of dealing with free chip geometry and chip-tool contact length. The coupling with thermal effects is also considered. Orthogonal cutting experiments are performed for 0.2% carbon steel with tools having 3 different edge radii and the tool forces are measured. The experimental results are discussed in comparison with the results of the FEM analysis. From the study, we confirm that this cutting model can well be applied to the cutting process considered the tool edge radius and that a major causes of the "size effect" is the tool edge radius. With numerical analysis, the effects of the tool edge radius on the stress distributions in workpiece, the temperature distributions in workpiece and tool, and the chip shape are investigated.estigated.

• International Journal of Precision Engineering and Manufacturing
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• 제6권1호
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• pp.65-72
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• 2005

Drilling process is one of the most common, yet complex operations among manufacturing processes. The performance of a drill is largely dependent upon drilling forces, Many researches focused on the effects of drill parameters on drilling forces. In this paper, an effective theoretical model to predict thrust and torque in drilling is presented. Also, with the predicted forces, the stress analysis of the drill tool is performed by the finite element method. The model uses the oblique cutting model for the cutting lips and the orthogonal cutting model for the chisel edge. Thrust and torque are calculated analytically without resorting to any drilling experiment, only by tool geometry, cutting conditions and material properties. The stress analysis is performed by the commercial FEM program ANSYS. The geometric modeling and the mesh generation of a twist drill are performed automatically. From the study, the effects of the variation of the geometric features of the drill and of the cutting conditions of the drilling on the drilling forces and the stress distributions in the tool are calculated analytically, which can be applicable for designing optimal drill geometry and for improving the drilling process.

• Coupled systems mechanics
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• 제2권1호
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• pp.23-51
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• 2013

An analytical algorithm for the estimation of the resistance forces exerted on the dipper of a cable shovel and the specific energy consumed in the cutting-loading process is presented. Forces due to payload and to cutting of geomaterials under given initial conditions, cutting trajectory of the bucket, bucket's design, and geomaterial properties are analytically computed. The excavation process has been modeled by means of a kinematical shovel model, as well as of dynamic payload and cutting resistance models. For the calculation of the cutting forces, a logsandwich passive failure mechanism of the geomaterial is considered, as has been found by considering that a slip surface propagates like a mixed mode crack. Subsequently, the Upper-Bound theorem of Limit Analysis Theory is applied for the approximate calculation of the maximum reacting forces exerted on the dipper of the cable shovel. This algorithm has been implemented into an Excel$^{TM}$ spreadsheet to facilitate user-friendly, "transparent" calculations and built-in data analysis techniques. Its use is demonstrated with a realistic application of a medium-sized shovel. It was found, among others, that the specific energy of cutting exhibits a size effect, such that it decreases as the (-1)-power of the cutting depth for the considered example application.

• 터널과지하공간
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• 제32권6호
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• pp.386-396
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• 2022

로드헤더에 미치는 변수의 영향력을 분석하기 위해 픽커터 절삭시험 관련 참고문헌들을 조사하였고, 수록된 데이터들을 수집하였다. 입력 인자는 일축압축강도, 절삭 깊이, 절삭 간격, 받음각, 비틀림각, 출력 인자는 비에너지, 절삭력, 수직력으로 결정했다. 입력 인자와 출력 인자로 분류 후 실험계획법을 작성하였고 분산분석을 이용해 변수들에 대한 기여도를 조사하였다. 그 결과, 절삭력과 비에너지에 가장 큰 영향을 미치는 요인은 일축압축강도와 절삭 간격으로 분석되었다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.483-488
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• 2005

The complex three-dimensional miniature components are needed for a wide range of applications from the aerospace to the biomedical industries. To manufacture these products, micro machining that can make a high aspect ratio part and has good accuracy is widely researched. In this paper, cutting characteristics were analyzed in micro machining using cutting force coefficients, which are the specific cutting force for normal and frictional direction of rake surface. From measured cutting force in micro end milling, cutting condition independent cutting force coefficients were determined and used for analysing the characteristics of micro cutting. Using the cutting force coefficient, 써써써.

• 한국터널지하공간학회 논문집
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• 제22권4호
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• pp.451-468
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• 2020

단면이 작게 만들어진 노후화된 터널은 만성적인 교통정체를 유발한다. 이는 터널의 확폭을 통하여 해결할 수 있다. 일반적으로 터널을 확폭할 경우, 기계식 또는 발파식 굴착방법을 통하여 기존터널의 외곽부를 굴착하게 된다. 이러한 굴착은 주변 지반뿐만 아니라 기존터널에도 영향을 미치게 된다. Pre-cutting 공법의 적용은 이러한 문제를 효과적으로 해결할 수 있는 방법이 될 수 있다. 따라서 Pre-cutting을 적용하여 확폭을 수행할 경우, 이에 따른 영향분석은 필수적으로 수행되어야 한다. 본 연구에서는 터널 확폭에서 Pre-cutting을 적용할 경우, 이에 따른 영향을 분석하기 위하여 6가지의 지반등급에서 수치해석을 수행하였다. 해석에서는 확대차로와 Pre-cutting의 굴착길이를 변수로 하여 수행하였으며, 기존터널과 확폭터널의 천단침하에 주목하여 분석하였다. 그 결과, 확폭터널의 천단침하는 확폭이 완료가 되면, Pre-cutting의 굴착 길이와 상관 없이 동일한 값으로 수렴하는 것을 확인하였다. 기존터널의 경우, 굴진면의 전방 5 m 내에서 융기가 발생하였으며, Pre-cutting의 굴착 길이가 짧을수록 융기 발생 예방에 효과적인 것으로 나타났다.

• 한국산학기술학회논문지
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• 제6권1호
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• pp.83-86
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• 2005

본 연구에서는 절삭 가공시 공구가 받는 절삭력과 칩-공구 사이에서 발생하는 절삭온도에 의한 공구의 변형을 예측하였다. 3D CAD를 이용하여 공구를 모델링 하였으며 절삭력과 절삭온도를 하중조건으로 부여하여 유한요소해석을 수행하였다. 하중조건으로 사용한 절삭력과 절삭온도는 절삭이론을 이용한 절삭력 모델을 사용하여 예측하였으며 실험을 통해 모델의 타당성을 검증하였다. 그러므로 본 연구는 절삭조건과 재료 물성치 그리고 공구 형상만을 알면 이에 따른 절삭력 성분 및 절삭온도 둥을 얻을 수 있고, 이를 이용하여 절삭 가공시 발생하는 공구의 변형을 예측할 수 있다.

• 한국정밀공학회지
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• 제18권3호
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• pp.195-204
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• 2001

Virtual computer numerical control(VCNC) arises from the concept that one can experience pseudo-real machining with a computer-numerically-controlled(CNC) machine before actually cutting an object. To achieve accurate VCNC, it is important to determine abnormal behavior, such as chatter, before cutting. Detecting chatter requires an understanding of the dynamic cutting force model. In general, the cutting process is a closed loop system that consists of structural and cutting dynamics. Machining instability, namely chatter, results from the interaction between these two dynamics. Several previous reports have predicted stability for a single path, using a simple cutting force model without tool runout and penetration effects. This study considers both tool runout and penetration effects, using experimental modal analysis, to obtain more accurate predictions. The machining stability in the corner cut, which is a typical transient cut, was assessed from an evaluation of the cutting configurations at the corner.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.519-524
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• 2000

This paper presents a study of surface roughness prediction model by experimental design in turning operation. Regression analysis technique has been used to study the effects of the cutting parameters such as cutting speed, feed and depth of cut on surface roughness. The experiment has been conducted using coated tungsten carbide inserts without cutting fluid. The reliability of the surface roughness model as a function of the cutting parameters has been estimated. The results show that the experimental design used in cutting process is a method to estimate the effects of cutting parameter on surface roughness.