Numerical Investigation of the Damage Evolution in Vibration Assisted Nano Impact Machining by Loose Abrasives With Different Operating Parameters

2018 ◽  
Author(s):  
Nick H. Duong ◽  
J. Ma ◽  
Shuting Lei
Keyword(s):  
Material Removal ◽  
Frictional Coefficient ◽  
Material Model ◽  
Impact Angle ◽  
Ductile Material ◽  
Nanoscale Material ◽  
Impact Speed ◽  
Atomic Force ◽  
Afm Probe ◽  
The Impact

In this paper, the commercial FEM software package Abaqus is employed to model a novel nanomachining process, in which an atomic force microscope (AFM) is used as a platform and the nano abrasives injected in slurry between the workpiece and the vibrating AFM probe impact the workpiece and result in nanoscale material removal. Diamond particles are used as loose abrasives. The ductile material model is used to describe the behavior of the silicon workpiece. The effects of impact speed, impact angle, and the frictional coefficient between the workpiece and abrasives on material removal mechanism are investigated. It is found that the impact speed, impact angle, and frictional coefficient between the silicon workpiece and nanoabrasives have big influence on material removal volume in this novel nanomachining process.

FEM Investigation of the Effects of Impact Speed and Angle of Impacts of Abrasive in the Vibration Assisted Nano Impact Machining by Loose Abrasives

2017 ◽  
Author(s):  
Nick H. Duong ◽  
J. Ma ◽  
Shuting Lei
Keyword(s):  
Frictional Coefficient ◽  
Impact Angle ◽  
The Novel ◽  
Abrasive Machining ◽  
Nanoscale Material ◽  
Impact Speed ◽  
Atomic Force ◽  
Hard And Brittle Materials ◽  
Afm Probe ◽  
The Impact

In this paper, the commercial FEM software package Abaqus is employed to model the novel nanomachining process, Vibration Assisted Nano Impact machining by Loose Abrasives (VANILA), which combines the principles of vibration-assisted abrasive machining and tip-based nanomachining to conduct nano abrasive machining of hard and brittle materials. In this novel nanomachining process, an atomic force microscope (AFM) is used as a platform and the nano abrasives injected in slurry between the workpiece and the vibrating AFM probe impact the workpiece and result in nanoscale material removal. Diamond particles are used as the loose abrasives. The effects of impact speed, angle of impacts, and the frictional coefficient between the workpiece and abrasives are investigated using Abaqus. It is found that the impact speed, impact angle, and frictional coefficient between the silicon workpiece and nanoabrasives have big influence on the nanocavity’s size and depth.

FEM Investigation of Damage Evolution at Elevated Temperatures With Multiple Impact Hits in Vibration Assisted Nano Impact Machining by Loose Abrasives

2019 ◽  
Author(s):  
Nick H. Duong ◽  
Jianfeng Ma ◽  
Shuting Lei ◽  
Murali Sundaram ◽  
Muhammad P. Jahan
Keyword(s):  
Material Removal ◽  
Elevated Temperatures ◽  
Operating Temperature ◽  
Computational Study ◽  
Frictional Coefficient ◽  
Impact Angle ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Multiple Impact ◽  
The Impact

Abstract In this paper, a computational study of a novel nanomachining process, Vibration Assisted Nano Impact machining by Loose Abrasives (VANILA), is conducted using the commercial FEM software package ABAQUS. In this novel nanomachining process, an atomic force microscope (AFM) is utilized as a platform and the nano abrasives are injected in the slurry which is located between the workpiece and the vibrating AFM probe. These nano abrasives impact the workpiece and result in nanoscale material removal. In this research, diamond particles are used as loose abrasives and the ductile mode machining is used to describe the behavior of the brittle silicon workpiece. This study aims to investigate the effects of operating temperature and number of multiple impact hits on material removal mechanism of VANILA process. The impact speed of the loose abrasives is kept constant at 200 m/s and the impact angle is fixed at 90°. The frictional coefficient during the machining is considered to be 0.05. The material removal mechanism at various operating temperatures (20°C, 100°C, 200°C, 400°C, 600°C, and 800°C) and multiple impacts are tested. It is found that the operating temperature and number of impact hits have substantial influence on material removal volume in the VANILA process.

Numerical Investigation of Effect of Operating Parameters on the Phase Transformation During Vibration-Assisted Nano-Impact Machining of Silicon by Loose Abrasives

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Nick H. Duong ◽  
Jianfeng Ma ◽  
Muhammad P. Jahan ◽  
Shuting Lei ◽  
Vamshi Krishna Kore ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Friction Coefficient ◽  
Impact Angle ◽  
Transformation Process ◽  
Impact Speed ◽  
Atomic Force ◽  
Afm Probe ◽  
Linear Regression Modeling ◽  
Impact Angles ◽  
The Relationship

Abstract Vibration-assisted nano-impact machining by loose abrasives (VANILA) is a newly developed process based on the atomic force microscope (AFM) platform, where the nanoabrasive (diamond particles) slurry is injected between the workpiece and the vibrating AFM probe. This study aims to use the commercial finite element method (FEM) software package abaqus to simulate the phase transformation experienced by the silicon workpiece and to study the effects of VANILA process parameters, such as impact speed, impact angle, and coefficient of friction between the nanoabrasive and silicon workpiece, on the volume of phase transformation of silicon. Among these three parameters, impact speed is found to have the most dominating effect on the phase transformation process, followed by impact angle and friction coefficient. It is found that the volumes for Si-VII, Si-VIII, and Si-X phases increase with the increase of impact speed from 100 m/s to 200 m/s. The phase volumes of Si-VII and Si-VIII are found to decrease slightly with the increase of friction coefficient from 0.05 to 0.5. The phase volumes for Si-VII, Si-VIII, and Si-X are found to increase with the increase of impact angles from 20 deg to 90 deg. Finally, the multiple linear regression modeling using a design of experiments is carried out to study the relationship among the three parameters and the volume of different phases of silicon.

FEM Investigation of Phase Transformation in Vibration Assisted Nano Impact Machining by Loose Abrasives (VANILA)

2018 ◽  
Author(s):  
Nick H. Duong ◽  
J. Ma ◽  
Muhammad P. Jahan ◽  
Shuting Lei ◽  
Murali Sundaram
Keyword(s):  
Phase Transformation ◽  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Numerical Study ◽  
Impact Angle ◽  
Machining Parameters ◽  
Phase Volume ◽  
Impact Speed ◽  
Afm Probe ◽  
The Impact

In this paper, a numerical study of a nanomachining process, Vibration Assisted Nano Impact machining by Loose Abrasives (VANILA), has been conducted. In the VANILA process, an atomic force microscope (AFM) is used as a platform and the nano abrasives (diamond particles) are injected in slurry between the silicon workpiece and the vibrating AFM probe. The vibration of the AFM probe generates kinetic energy for the abrasives to impact the silicon workpiece and result in nanoscale material removal. In addition, silicon usually experiences phase transformation when subject to high pressure at nano-scale. The commercial Finite Element Method (FEM) software package Abaqus is employed to simulate the phase transformation experienced by the silicon workpiece in this VANILA process under different machining parameters such as impact speed, impact angle and coefficient of friction between the nano-abrasive and silicon workpiece. It is found that the machining parameters (impact speed, impact angle, and coefficient of friction) have substantial influence on the phase transformation of silicon workpiece in the nanomachining VANILA. Phase volumes for Si-VII, Si-VIII, and Si-X increase as the impact speed increases from 100 m/s to 200 m/s. Phase volume of Si-X increases as the friction coefficient increases. For Si-VII and Si-VIII, the phase volumes decrease as friction coefficient increases from 0.05, 0.3 and 0.5. In addition, the phase volumes for Si-VII, Si-VIII, and Si-X usually increase as the impact angles increases from 20° to 90°. However, for impact speed of 150 m/s and frictional coefficient of 0.05, the Si-VII phase volume increases first as impact angle increases from 20° to 70° and then decreases as the impact angle increases from 70° to 90°.

scholarly journals Mechanical Properties of Electrospun, Blended Fibrinogen: PCL Nanofibers

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1843
Author(s):  
Jacquelyn M. Sharpe ◽  
Hyunsu Lee ◽  
Adam R. Hall ◽  
Keith Bonin ◽  
Martin Guthold
Keyword(s):  
Mechanical Properties ◽  
Strain Softening ◽  
Electrospun Nanofibers ◽  
High Energy ◽  
Optical Microscope ◽  
Ductile Material ◽  
Breaking Strain ◽  
Atomic Force ◽  
Microscope Technique ◽  
Afm Probe

Electrospun nanofibers manufactured from biocompatible materials are used in numerous bioengineering applications, such as tissue engineering, creating organoids or dressings, and drug delivery. In many of these applications, the morphological and mechanical properties of the single fiber affect their function. We used a combined atomic force microscope (AFM)/optical microscope technique to determine the mechanical properties of nanofibers that were electrospun from a 50:50 fibrinogen:PCL (poly-ε-caprolactone) blend. Both of these materials are widely available and biocompatible. Fibers were spun onto a striated substrate with 6 μm wide grooves, anchored with epoxy on the ridges and pulled with the AFM probe. The fibers showed significant strain softening, as the modulus decreased from an initial value of 1700 MPa (5–10% strain) to 110 MPa (>40% strain). Despite this extreme strain softening, these fibers were very extensible, with a breaking strain of 100%. The fibers exhibited high energy loss (up to 70%) and strains larger than 5% permanently deformed the fibers. These fibers displayed the stress–strain curves of a ductile material. We provide a comparison of the mechanical properties of these blended fibers with other electrospun and natural nanofibers. This work expands a growing library of mechanically characterized, electrospun materials for biomedical applications.

scholarly journals Modeling of Tool Wear in Vibration Assisted Nano Impact-Machining by Loose Abrasives

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Sagil James ◽  
Murali M. Sundaram
Keyword(s):  
Wear Rate ◽  
Tool Wear ◽  
Experimental Studies ◽  
Tool Wear Rate ◽  
Nanoscale Material ◽  
Workpiece Surface ◽  
Atomic Force ◽  
Hard And Brittle Materials ◽  
Afm Probe

Vibration assisted nano impact-machining by loose abrasives (VANILA) is a novel nanomachining process that combines the principles of vibration assisted abrasive machining and tip-based nanomachining, to perform target specific nanoabrasive machining of hard and brittle materials. An atomic force microscope (AFM) is used as a platform in this process wherein nanoabrasives, injected in slurry between the workpiece and the vibrating AFM probe which is the tool, impact the workpiece and cause nanoscale material removal. The VANILA process are conducted such that the tool tip does not directly contact the workpiece. The level of precision and quality of the machined features in a nanomachining process is contingent on the tool wear which is inevitable. Initial experimental studies have demonstrated reduced tool wear in the VANILA process as compared to indentation process in which the tool directly contacts the workpiece surface. In this study, the tool wear rate during the VANILA process is analytically modeled considering impacts of abrasive grains on the tool tip surface. Experiments are conducted using several tools in order to validate the predictions of the theoretical model. It is seen that the model is capable of accurately predicting the tool wear rate within 10% deviation.

IMPACT FORCE RESPONSE OF SHORT CONCRETE FILLED STEEL TUBULAR COLUMNS UNDER AXIAL LOAD

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1361-1368 ◽  
Author(s):  
GOUPING REN ◽  
ZHU LI
Keyword(s):  
Impact Force ◽  
Time History ◽  
Material Model ◽  
Critical Energy ◽  
Steel Tube ◽  
Peak Force ◽  
Impact Speed ◽  
Tubular Columns ◽  
Unitary Model ◽  
The Impact

The impact test on short concrete filled steel tubular column was conducted through DHR-9401 dropped hammer tester. Based on analysis on recorded time-history curve of impact force, the relations of impact force with respect to confining effect coefficient and impact speed are obtained. So are done that of the impact duration. By use of ANSYS/LS-DYNA, values of impact peak force in relation with those of impact speed were computed in the case of unitary material model and composite material model respectively. The simulation results show that peak force-speed curve of unitary model has better description of test data than that of composite one. Critical energy is found to increase linearly with the steel ratio when steel tube and concrete remain unchanged.

A study on the frontal oblique collision-induced derailment mechanism in subway vehicles

2019 ◽  
Vol 234 (6) ◽  
pp. 584-595
Author(s):  
Shuguang Yao ◽  
Huifen Zhu ◽  
Mingyang Liu ◽  
Zhixiang Li ◽  
Ping Xu ◽  
...  
Keyword(s):  
Lateral Displacement ◽  
Element Model ◽  
Vertical Displacement ◽  
Rigid Wall ◽  
Impact Angle ◽  
Oblique Impact ◽  
Oblique Collision ◽  
Impact Speed ◽  
Vertical Displacements ◽  
The Impact

Oblique collisions can more easily lead to train derailment and cause heavy casualties. In this paper, a fine finite-element model of a subway head vehicle–rigid wall frontal oblique collision was established and validated by a single wheelset derailment simulation. Furthermore, the derailment mechanisms and patterns under an oblique impact angle of 6.34°–40° and at an impact speed of 8–40 km/h were studied via simulation. The results indicated that three types of derailment, such as roll-over derailment, climb/roll-over derailment and wheel-lift derailment, have occurred. When the impact speed was set to 25 km/h, a climb/roll-over derailment occurred under the impact angle of greater than 40°; a roll-over derailment occurred under the impact angle of 20°–40°; and the vehicle would not derail when the impact angle was less than 15°. When the impact angle was 6.34°, the vehicle was in danger of wheel-lift derailment with the largest wheel vertical displacement of 26.83 mm and lateral displacement of 12.52 mm under the impact speed of 40 km/h, but it was safe with the largest displacement of no more than 18 mm and lateral displacement of 8.39 mm if the impact speed was less than 40 km/h. It is shown that the derailment patterns are more sensitive to the impact angle. Therefore, both the lateral and vertical displacements should be considered when studying the oblique collision-induced derailment mechanisms and patterns.

scholarly journals Neck Moment Characterization of Restrained Child Occupant at Realistic Nontest Standard Higher Impact Speed of 32.2 km/h

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
S. Shasthri ◽  
V. Kausalyah ◽  
Qasim H. Shah ◽  
Kassim A. Abdullah ◽  
Moumen M. Idres ◽  
...  
Keyword(s):  
Interactive Effect ◽  
Impact Angle ◽  
Side Impact ◽  
Impact Speed ◽  
Child Restraint ◽  
Child Restraint System ◽  
Impact Angles ◽  
Child Occupant ◽  
The Impact

The effects of bullet vehicle crash impact angle, child restraint system design, and restraint harness slack at side impact speed of 32.2 km/h (20 mph) on moments sustained at the neck by a three-year-old child are investigated. Mathematical models are built using the response surface method based on simulation results whereby good fitness is achieved. The singular and cross interactive effect of each predictor on the neck moment are analyzed. The number of significant parameters affecting the neck moment is shown to be the largest for wide impact angles (ϕ≥60°) and the impact angle parameter is largely revealed to be the most sensitive. An ideal safe range for low neck moment has been established to be within ϕ angles 45° and 65°. It is further shown that the nature of all parameters effect on the neck moment is highly dependent on the impact angle range.

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