scholarly journals Constant Chip Volume Machining

2016 ◽  
pp. 0960-0966
Author(s):  
Jan Hnatik ◽  
Lubos Kroft ◽  
Jan Kutlwaser
Keyword(s):  
Chip Volume

Molecular Dynamics and Multiscale Simulations of Nanoindentation and Nanoscratch

2010 ◽  
Author(s):  
Peng-zhe Zhu ◽  
Hui Wang ◽  
Yuan-zhong Hu
Keyword(s):  
Molecular Dynamics ◽  
Computational Cost ◽  
Three Dimensional ◽  
Multiscale Model ◽  
Md Simulations ◽  
System Size ◽  
Multiscale Simulations ◽  
First Case ◽  
Chip Volume ◽  
Indenter Shape

Three-dimensional molecular dynamics (MD) simulations have been performed to investigate behaviors of nanoindentation and nano-scratch. The first case concerns the effects of material defect on the nanoindentation of nickel thin film. The defect is modeled by a spherical void embedded in the substrate and located under the surface of indentation. The simulation results reveal that compared to the case without defect, the presence of the void softens the material and allows for larger indentation depth at a given load. MD simulations are then performed for nano-scratch of single crystal copper, with emphasis on the effect of indenter shape (sharp and blunt) on the substrate deformation. The results show that the blunt indenter causes larger deformation region and much more dislocations at both the indentation and scratch stages. It is also found that during the scratching stage the blunt indenter results in larger chip volume in front of the indenter and gives rise to more friction than the sharp indenter. The scope of the simulations has been extended by introducing a multiscale model which couples MD simulations with Finite Element Method (FEM), and multiscale simulations are performed for two-dimensional nanoindentation of copper. The model has been validated by well-consistent load-depth curves obtained from both multiscale and full MD simulations, and by good continuity of deformation observed in the handshake region. The simulations also reveal that indenter radius and indentation velocity significantly affect the nanoindentation behavior. By use of multiscale method, the system size to be explored can be greatly expanded without increasing much computational cost.

Chip Load Kinematics in Milling With Radial Cutter Runout

1996 ◽  
Vol 118 (1) ◽  
pp. 111-116 ◽  
Author(s):  
J.-J. Junz Wang ◽  
S. Y. Liang
Keyword(s):  
Chip Thickness ◽  
Machining Process ◽  
Volume Distribution ◽  
Monitoring And Control ◽  
Cutter Runout ◽  
Validity Assessment ◽  
Thickness Prediction ◽  
Milling Forces ◽  
Chip Load ◽  
Chip Volume

This paper presents the analytical modeling of chip load and chip volume distribution in milling processes in the presence of cutter runout. The understanding of chip load kinematics has a strong bearing on the prediction of milling forces, on the assessment of resulting surface finish and tool vibration, and on the identification of runout for multi-toothed machining process monitoring and control. In this study a chip thickness expression is analytically established in terms of the number of flutes, the cutter offset location and the ratio of offset magnitude to feed per tooth. The effects of runout geometry, feed rate, and depths of cut on the overall chip generating action is discussed through the illustration of cutting regions and chip load maps. Explicit solutions for the entry and exit angles are formulated in the context of milling parameters and configuration. Experimental measurement of the resulting chip volumes from machining with an offset cutter is compared to an analytical model formulated from the chip thickness expression. Additionally, an average chip thickness prediction, based on the chip volume model in combination with the entry/exit angle solutions, is compared to data reported in the literature for validity assessment.

scholarly journals Concept and proof for an all-silicon MEMS micro speaker utilizing air chambers

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Bert Kaiser ◽  
Sergiu Langa ◽  
Lutz Ehrig ◽  
Michael Stolz ◽  
Hermann Schenk ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Harmonic Distortion ◽  
Smart Devices ◽  
Mems Devices ◽  
Key Factors ◽  
Unit Costs ◽  
Linearity Improvement ◽  
Design Options ◽  
High Sound ◽  
Chip Volume

Abstract MEMS-based micro speakers are attractive candidates as sound transducers for smart devices, particularly wearables and hearables. For such devices, high sound pressure levels, low harmonic distortion and low power consumption are required for industrial, consumer and medical applications. The ability to integrate with microelectronic circuitry, as well as scalable batch production to enable low unit costs, are the key factors benchmarking a technology. The Nanoscopic Electrostatic Drive based, novel micro speaker concept presented in this work essentially comprises in-plane, electrostatic bending actuators, and uses the chip volume rather than the its surface for sound generation. We describe the principle, design, fabrication, and first characterization results. Various design options and governing equations are given and discussed. In a standard acoustical test setup (ear simulator), a MEMS micro speaker generated a sound pressure level of 69 dB at 500 Hz with a total harmonic distortion of 4.4%, thus proving the concept. Further potential on sound pressure as well as linearity improvement is outlined. We expect that the described methods can be used to enhance and design other MEMS devices and foster modeling and simulation approaches.

Modeling the effects of Undeformed Chip Volume (UCV) on residual stresses during the milling of curved thin-walled parts

2020 ◽  
Vol 167 ◽  
pp. 105162 ◽  
Author(s):  
Xiaohui Jiang ◽  
Xiangjing Kong ◽  
Zhenya Zhang ◽  
Zhouping Wu ◽  
Zishan Ding ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Thin Walled ◽  
Chip Volume

Single Grain Scratch Tests to Determine Elastic and Plastic Material Behavior in Grinding

2011 ◽  
Vol 325 ◽  
pp. 48-53 ◽  
Author(s):  
Jan C. Aurich ◽  
M. Steffes
Keyword(s):  
Plastic Material ◽  
Cutting Speed ◽  
Material Behavior ◽  
Cutting Process ◽  
Pile Up ◽  
Single Grain ◽  
Scratch Tests ◽  
Different Sources ◽  
Chip Volume ◽  
Cutting Speeds

This paper presents an overview of kinematic simulations in grinding. Up to now the simulations are carried out under the assumption of an ideal cutting process. Therefore, the simulation results are not exactly identical to the experimental results. For this reason, the simulation needs to be enhanced with the plastic material flow during cutting. To explain this behavior, single grain scratch experiments were conducted to detect the different sources of influence on the plastic deformation and on the pile-up. First, in the experiments the grain shapes as well as the cutting speeds were varied. To take the effect of different grain shapes into account, three different grains were used. The effect of the cutting speed was investigated at cutting speeds ranging from 60 to 120 m/s. The results were evaluated with a confocal microscope. To quantify the results of the efficiency of the cutting process, the relative chip volume parameter was used.

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