Determination of Flow Stress and Cutting Force Prediction of Ti-6Al-4V Material for 3D Printer using S-K Constitutive Equation

Dae-Gyoun Park(박대균),Tae-Ho Kim(김태호),Eon-Chan Jeon(전언찬) 한국기계가공학회 2018 한국기계가공학회지 Vol.17 No.6

Study on the Ti-6Al-4V have been carried out using cutting simulation, and researches for cutting force and chip shape prediction have been actively conducted under various conditions. However, a 3D printer application method using Ti-6Al-4V metal powder material as a high-power method has been studied for the purpose of prototyping, mold modification and product modification while lowering material removal rate. However, in the case of products / parts made of 3D printers using powder materials, problems may occur in the contact surface during tolerance management and assembly due to the degradation of the surface quality. As a result, even if a 3D printer is applied, post-processing through cutting is essential for surface quality improvement and tolerance management. In the cutting simulation, the cutting force and the chip shape were predicted based on the Johnson-Cook composition equation, but the shape of the shear type chip was not predictable. To solve this problem, we added a damaging term or strain softening term to the Johnson-Cook constitutive equation to predict chip shape. In this thesis, we applied the constant value of the S-K equations to the cutting simulation to predict the cutting force and compare with the experimental data to verify the validity of the cutting simulation and analyzed the machining characterization by considering conditions.

아레니우스 타입 구성식을 통한 알루미늄 합금의 고속 변형거동 예측

정대관(D. K. Joung),최호준(H. J. Choi),신영철 한국소성가공학회 2019 한국소성가공학회 학술대회 논문집 Vol.2019 No.10

롤포밍 공정에서의 성형방법에 따른 직진성 예측

정상화,이상희,김재상,박진완,임성빈 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.2

Roll forming process is one of the most widely used processes in the world for forming metals. It can manufacture goods of the uniform cross section throughout the continuous processing. However, analysis of process is very difficult because of the inherent complexity of the process. For this reason, the computer analysis methods such as the FEM(Finite Element Method) and the FDM(Finite Difference Method) are frequently used in roll forming design. In this paper, the under rail composed of upper member, center member and lower member is modeled. Also the flower pattern of the upper member is designed and the roll forming process is simulated. The upper member is designed using constant arc length forming method and constant radius forming method for excellent design. The cold rolled carbon steel sheet(SCP-l) is used in this simulation, and a flow stress equation is set up through the tensile test. Each types are simulated and compared with the longitudinal strain using SHAPE-RF software. In addition. the numerical magnitude of camber and bow is predicted from the results of the simulation.

FEM을 이용한 롤 포밍 공정의 3차원 모델링

정상화(Sang Hwa Jeong),이상희(Sang Hee Lee) 한국생산제조학회 2007 한국생산제조시스템학회 학술발표대회 논문집 Vol.2007 No.5

Cold-roll-forming (CRF) is a well known process used to manufacture long sheet metal products with a constant cross section. It can manufacture goods of the uniform cross section on a large scale as a continuous processing. Also it is a very important process in many industrial fields to increase of the application. However, product design procedures, in terms of rolls design and rolls pass schedule, remain rather an art than science. Therefore, many times and money are needed for manufacturing goods. In order to overcome this difficulty, a new computational method based on the rigid-plastic finite method is developed for the analysis of roll forming process and the optimum design. Analysis using FEM(Finite Element Method) and FDM(Finite Difference Method) is used in the deformation analysis. In this paper, to make lower member for under rail roll using FEM simulation software(SHAPE-RF), the roll forming 3-D modeling and simulation are performed, Tensile test is performed about SCP-1 for input properties to program. Besides, curve fitting is executed to set up the flow stress equation. Final shape is predicted after 11-pass. The longitudinal strain is estimated on the basis of simulation result. In addition, Bow and Camber which is one of the several defects are measured.

FEM을 이용한 롤 포밍 공정의 3차원 모델링

정상화(Sang Hwa Jeong),이상희(Sang Hee Lee) 한국생산제조학회 2007 한국공작기계학회 춘계학술대회논문집 Vol.2007 No.-

Cold-roll-forming (CRF) is a well known process used to manufacture long sheet metal products with a constant cross section. It can manufacture goods of the uniform cross section on a large scale as a continuous processing. Also it is a very important process in many industrial fields to increase of the application. However, product design procedures, in terms of rolls design and rolls pass schedule, remain rather an art than science. Therefore, many times and money are needed for manufacturing goods. In order to overcome this difficulty, a new computational method based on the rigid-plastic finite method is developed for the analysis of roll forming process and the optimum design. Analysis using FEM(Finite Element Method) and FDM(Finite Difference Method) is used in the deformation analysis. In this paper, to make lower member for under rail roll using FEM simulation software(SHAPE-RF), the roll forming 3-D modeling and simulation are performed, Tensile test is performed about SCP-1 for input properties to program. Besides, curve fitting is executed to set up the flow stress equation. Final shape is predicted after 11-pass. The longitudinal strain is estimated on the basis of simulation result. In addition, Bow and Camber which is one of the several defects are measured.

롤 포밍 공정에서의 길이방향 변형률 및 직진성 예측

정상화(Sang-Hwa Jeong),이상희(Sang-Hee Lee) 한국기계가공학회 2007 한국기계가공학회 춘추계학술대회 논문집 Vol.2007 No.-

Cold roll forming can be described basically as a process where a metal sheet is continuously formed in the transverse direction into a product with a desired cross-sectional profile by passing a series of pairs of forming rolls. However, process analysis is very difficult because deformation procedures are quite complex and have many variable. The cold-roll forming has been mostly developed through the experimental knowledge. In order to overcome this difficulty, the roll forming process for manufacturing the under rail is analyzed using a new computational method based on the rigid-plastic finite element. In this paper, the roll forming process of the lower member at under rail is simulated using simulation software. Tensile test is performed about SCP-1 to obtain material properties and curve fitting is executed to set up the flow stress equation. The lower member is designed using the constant arc length forming method and the constant radius forming method for excellent design. The longitudinal strain is estimated on the basis of simulation results. In addition, the numerical magnitudes of camber and bow are predicted from the results of the simulation

3D 프린팅으로 제작한 Ti-6Al-4V 재료의 Johnson-Cook 모델의 유동 응력 결정

박대균(Dae-Gyoun Park),김태호(Tae-Ho Kim),전언찬(Eon-Chan Jeon) 한국기계가공학회 2018 한국기계가공학회지 Vol.17 No.4

This paper investigates the compressive deformation behavior of direct metal tooling (DMT), processing titanium alloy (Ti-6Al-4V) parts under high strain loading conditions. Split Hopkinson Pressure Bar (SHPB) experiments were performed to determine the flow stress and the coefficients of the Johnson-Cook model. This model is described as a function of strain, strain rate, and temperature. SHPB experiments were performed to characterize the deformation behavior of specimens made with 3D printers, using Ti-6Al-4V material under high temperature and dynamic loading.

강소성 유한요소법을 이용한 롤포밍 시뮬레이션

정상화,이상희,김광호,김주환,신상문 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

The slide rail is the latest device driven by rectilinear reciprocating motion. It is used for the great deal of fields with the progress of high technology in these days: for example, telecommunication device, measurement device, copy machine, refrigerator, car, office furniture and wood furniture, etc., But it is very difficult to produce the press mold that has a. forming of narrow thickness, straight quality and high accuracy. Recently Roll forming technique is used to fabricate the slide rail. To evaluate the characteristics of each path shape is not easy because the roll forming passes the sheet metal in the continuously arranged multistage roll stands. In this paper, Roll forming simulation is performed to make U-channel using SHARP-RF. Longitudinal strain and total effective strain are evaluated. In addition, Bowing and Camber which is one of the several defects are measured.

언더레일 성형을 위한 롤포밍 공정 설계

정상화,이상희 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

Roll forming process is one of the most widely used processes in the world for forming metals. It can manufacture goods of the uniform cross section throughout the continuous processing. However, analysis of process is very difficult because of the inherent complexity of the process. For this reason, the computer analysis methods such as the FEM(Finite Element Method) and the FDM(Finite Difference Method) are frequently used in roll forming design. In this paper, the under rail composed of upper member, center member and lower member is modeled. Also the flower pattern of the upper member is designed and the roll forming process is simulated. The upper member is designed using constant arc length forming method and constant radius forming method for excellent design. The cold rolled carbon steel sheet(SCP-1) is used in this simulation, and a flow stress equation is set up through the tensile test. Each types are simulated and compared with the longitudinal strain using SHAPE-RF software. In addition, the numerical magnitude of camber and bow are predicted from the results of the simulation.

강소성 유한요소법을 이용한 롤포밍 시뮬레이션

정상화(Sang Hwa Jeong),이상희(Sang Hee Lee),김광호(Gwang Ho Kim),김주환(Ju Hwan Kim),신상문(Sang Moon Shin) 한국생산제조학회 2006 한국생산제조시스템학회 학술발표대회 논문집 Vol.2006 No.5

The slide rail is the latest device driven by rectilinear reciprocating motion. It is used for the great deal of fields with the progress of high technology in these days: for example, telecommunication device, measurement device, copy machine, refrigerator, car, office furniture and wood furniture, etc., But it is very difficult to produce the press mold that has a. forming of narrow thickness, straight quality and high accuracy. Recently Roll forming technique is used to fabricate the slide rail. To evaluate the characteristics of each path shape is not easy because the roll forming passes the sheet metal in the continuously arranged multistage roll stands. In this paper, Roll forming simulation is performed to make U-channel using SHARP-RF. Longitudinal strain and total effective strain are evaluated. In addition, Bowing and Camber which is one of the several defects are measured.