Numerical Modeling of Stacked Composite CFRP/Ti Machining under Different Cutting Sequence Strategies

Jinyang Xu,Mohamed El Mansori 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.1

Stacked composite CFRP/Ti is identified as an innovative structural configuration for manufacturing the key aircraft components favoring energy saving in the modern aerospace industry. Machining of this composite-to-metal alliance exhibits the most challenging task in manufacturing community due to the disparate natures of each phase involved and their respective poor machinability. Since the experimental studies are highly cost and time consuming, the numerical approach should be a capable alternative to overcoming the several technical limitations involved. In this research, an original FE model was developed to simulate the complete chip formation process when orthogonal cutting (OC) of hybrid CFRP/Ti stacks. Different constitutive models and failure criteria were implemented into the Abaqus/Explicit code to construct the entire machining behavior of the stacked composite material. The stack model was built to replicate accurately the key physical phenomena activated in the hybrid cutting operation. Special concentration was made on the comparative studies of the effects of different cutting-sequence strategies on the machining responses induced by CFRP/Ti cutting. The numerical results highlighted the significant role of cutting-sequence strategy in affecting the final machined surface morphology and subsurface damage extent, and hence emphasized the importance of selecting reasonable cutting-sequence strategy for hybrid CFRP/Ti machining.

엔드밀 가공시 진동, 표면거칠기, 절삭온도에 미치는 최적가공조건에 관한 연구

홍도관(Hong, Do-Kwan),김동영(Kim, Dong-Young),안찬우(Ahn, Chan-Woo) 한국소음진동공학회 2004 한국소음진동공학회 논문집 Vol.14 No.12

End-milling has been used widely in industrial system because it is effective to a material manufacturing with various shapes. Recently the end-milling processing is needed the high-precise technique with good surface roughness and rapid time in precision machine part and electronic part. The optimum mechanical vibration of main spindle, surface roughness and cutting temperature have an effect on end-milling condition such as, cutting direction, revolution of spindle, feed rate and depth of cut, etc. Therefore, this study carried to decide the working condition for optimum mechanical vibration of main spindle, surface roughness and cutting temperature using design of experiments, ANOVA and characteristic function. From the results of experimentation, mechanical vibration has an effect on revolution of spindle, radial depth of cut, and axial depth of cut. The surface roughness has an effect on cutting direction, revolution of spindle and depth of cut. And then the optimum condition used design of experiments is upward cutting In cutting direction, 600 rpm in revolution of spindle, 240 mm/min in feed rate, 2 mm in axial depth of cut and 0.25 mm in radial depth of cut. By design of experiments and characteristic function, it is effectively represented shape characteristics of mechanical vibration, surface roughness and cutting temperature in end-milling.

다구찌 실험 계획법을 이용한 고속가공에서 공구수명 조건의 최적화

양균의,임표 한국기계가공학회 2006 한국기계가공학회지 Vol.5 No.4

High Speed Machining(HSM) reduces machining time and improves surface accuracy because of the high cutting speed and feedrate. Development of HSM makes it allowable to machine difficult-to-cut material and use small-size-endmill. It is however limited to cutting condition and tool material. In the machining operation, it is important to check main parameter of tool life and select optimal cutting condition because tool breakage can interrupt progression of operation. In this study, cutting parameters are determined to 3 factors and 3 levels which are a spindle speed, a feedrate and a width of cut. Experiment is designed to orthogonal array table for L9 with 3 outer array using Taguchi method. Also, it is proposed to inspect significance of the optimal factors and levels by ANOVA using average of SN ratio for tool life. Finally, estimated value of SN ratio in the optimal cutting condition is compared with measured one in the floor shop and reduction of loss is predicted.

직교형 2차원 진동절삭기의 기구학적 해석 및 진동 특성 고찰

노병국(Loh, Byoung-Gook),김기대(Kim, Gi-Dae) 한국소음진동공학회 2012 한국소음진동공학회 논문집 Vol.22 No.9

In elliptical vibration cutting(EVC) where the cutting tool traces a micro-scale 2-dimensional elliptical trajectory, the kinematical and vibrational characteristics of the EVC device greatly affect cutting performance. In this study, kinematical and vibrational characteristics of an EVC device constructed with two orthogonally-arranged stacked piezoelectric actuators were investigated both analytically and experimentally. The step voltage was applied to the orthogonal EVC device and the associated displacements of the cutting tool were measured to assess kinematical characteristics of the orthogonal EVC device. To investigate the vibrational characteristic of the orthogonal EVC, sinusoidal voltage was applied to the EVC device and the resulting displacements were measured. It was found from experiments that coupling of displacements in the thrust and cutting directions and the tilt of the major axis of the elliptical trajectory exists. In addition, as the excitation frequency is in vicinity of resonant frequencies the distortion in the shape of the elliptical trajectory becomes greater and change in the rotation direction occurs. To correct the shape distortion of the elliptical trajectory, the shape correcting procedure developed for the parallel EVC device was applied for the orthogonal EVC device and it was shown that the shape correcting method successfully corrects distortion.

Experimental Study on the Deformation of a Cut-Off Wall in a Landfill

Guozhong Dai,Jia Zhu,Yang Song,Shujin Li,Guicai Shi 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.5

To effectively solve the leakage problem of landfill leachate, it is necessary to establish a vertical cut-off wall around the landfill site for seepage control. To accurately analyze the deformation of the cut-off wall, a 1/8-scale landfill cut-off wall miniature model is designed and fabricated. The actual force of the cut-off wall is simulated by filling sand on the outer side of the model wall. Meanwhile, a nonlinear finite element model of the wall is established using the ANSYS to simulate the deformation of the seepage wall. The results show that the cut-off wall made from a polyvinyl alcohol-bentonite-fly ash-cement (PBFC) anti-seepage slurry has a high ultimate bearing capacity, and its ultimate strain is approximately 5%, which is much higher than the limit strain of the actual force conditions of the cut-off wall. The horizontal displacement of the cut-off wall is approximately linear and decreases gradually from the top to the bottom, and no reverse displacement is observed. The main stress of the wall is smaller than that of the slurry, and there is no tensile stress. The simulated results are similar to the measured values of the cut-off wall, which indicates the accuracy of the simulation analysis.

Cutting Modeling Using Cohesive Zone Concept of Titanium/CFRP Composite Stacks

Jinyang Xu,Mohamed El Mansori 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

In modern aerospace industry, hybrid CFRP/Ti stacks have taken a prominent position in manufacturing aircraft and spacecraft structural components due to their combined resistance and enhanced characteristics favoring the energy saving. Compared to the great interest of experimental studies, nearly rare scientific literature deals with the numerical modeling of hybrid CFRP/Ti cutting. This is the key incentive that motivates the current research to propose an original FE model to address the mentioned issues. The FE model was developed into Abaqus/Explicit commercial code. The CFRP phase was modeled as an equivalent homogeneous material (EHM) by implementing Hashin damage criteria to simulate the rupture and separation of the fiber/matrix system. The Ti phase was assumed isotropic with elastoplastic behavior, and Johnson-Cook criteria were utilized to replicate the local failure of the metallic phase. The CFRP/Ti interface physically described as an intermediate constituent was modeled through the concept of cohesive zone (CZ). The multiple aspects of machining responses induced in hybrid CFRP/Ti cutting were precisely investigated with a special focus on the interface damage formation. The numerical results highlighted the significant effects of feed rate on the force generation and the pivotal role of bi-material interface consumption (BIC) in affecting the interface delamination.

2차원 기계가공면의 표면성상에 관한 연구

문상돈,오성훈 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2002 工學硏究 Vol.33 No.-

Metal cutting leaves a plastically deformed layer in the machined surface. This deformed layer affects in various forms to the physical properties of machined components such as the dimensional instability, the micro crack. These physical properties is called surface integrity which is very important in precision cutting. In this study, we introduce plastic strain, surface roughness, cutting force to evaluate surface integrity of machined surface, and examine mutual relation of these parameters.

TiAlN 코팅 엔드밀공구 R-Curve 가공시 절삭력이 공구에 미치는 영향

김원중(Won - Jung Kim),백용하(Yong -Ha Baek) 산업기술교육훈련학회 2010 산업기술연구논문지 (JITR) Vol.15 No.4

It is the required of high precision and high efficiency machining process for most of the mechanical and electronic parts along with the rapid development of modern industry. Necessity of efficient R-curve processing is rising in the machine and parts industry of electronics industry and troy industry field. In machining experimentation the results of R-curve, When spindle speed 25,000 rpm and feed rate 2,000mm/min and depth of cut 0.1mm, it was shown the best result as surface roughness. also, When R-curve machining, it is analyzed that it is affected in tool wear in increase of spindle speed and Cutting force and depth of cut.

TiAIN 코팅 엔드밀공구 R-Curve 가공시 절삭력이 공구에 미치는 영향

김원중(Won Jung Kim),백용하(Yong Ha Baek) 산업기술교육훈련학회 2010 산업기술연구논문지 (JITR) Vol.15 No.4

It is the required of high precision and high efficiency machining process for most of the mechanical and electronic parts along with the rapid development of modern industry. Necessity of efficient R-curve processing is rising in the machine and parts industry of electronics industry and troy industry field. In machining experimentation the results of R-curve, When spindle speed 25,000 rpm and feed rate 2,000mm/min and depth of cut 0.lmm, it was shown the best result as surface roughness. also, When R-curve machining, it is analyzed that it is affected in tool wear in increase of spindle speed and Cutting force and depth of cut.

Effect of rake angle on cutting performance during machining of stone-plastic composite material with polycrystalline diamond cutters

Pingxiang Cao,Zhaolong Zhu,Dietrich Buck,Xiaolei Guo,Mats Ekevad,Xiaodong (Alice) Wang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

This study investigates the effect of rake angle on cutting performance during machining of stone-plastic composite material with diamond cutters. To that end, an orthogonal cutting experiment was designed, in which stone-plastic composite material was planed by a polycrystalline diamond (PCD) cutter to produce chips. The features studied include cutting forces, cutting heat, chip formation and cutting quality. The conclusions are as follows: Firstly, increased rake angle causes frictional force and resulting force to decrease, promoting an increase in normal force. Secondly, during planing, cutting heat is primarily distributed in the chips, with less retained in the cutting edge, and the least retained in the machined surface. The temperatures of both cutting edge and chip decline with an increase in rake angle. Thirdly, as rake angle increases, chip morphology changes from segmental to curved and then to particle chips, with chip-breaking lengths first increasing and then decreasing. Finally, an increased rake angle leads a more stable cutting process and improved cutting quality. Therefore, with the precondition of blade strength, a diamond cutter with a larger rake angle can be used to machine stone-plastic composite to improve production quality by forming a smoother machined surface.