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Rowan Deam - One of the best experts on this subject based on the ideXlab platform.

  • particles impact characteristics on cutting surface during the abrasive water jet machining numerical study
    Journal of Materials Processing Technology, 2016
    Co-Authors: Dewan Hasan Ahmed, Jamal Naser, Rowan Deam
    Abstract:

    Abstract The cutting performance of an abrasive water jet mainly depends on the abrasive particle’s velocities and impact angles as well as the physical properties of the particles and the workpiece being cut. This ultimately causes the different modes of Erosion Process at the time of cutting of the job specimen. During the cutting Process the cutting profile changes with the depth of the cut to form the kerf. Due to the change of radius of curvature of the cutting surface with depth, the Erosion Process per unit depth decreases because of the changing of the impact angle. Here comprehensive numerical studies have been carried out to find the particle impact characteristics on the groove wall (cutting surface) as well as side walls for different radii of curvature. The results obtained from the simulations have indicated that the particle impact angles depend on the radius of curvature. The study has shown that the particles have a tendency to slide or stay close to the cutting surface for the large radius of curvature and have very small impact angles. The particles’ primary impact velocity are decreased little, however, the particle’s impact velocities are significantly decreased for the secondary, tertiary and following impacts due to fluid drag. The numerical simulation results have been used to calculate the particle’s distribution factor for both deformation wear and cutting wear. The distribution factors indicate that the particles have tendency to slide on the groove wall for higher radius of curvature. These findings are consistent with the literature.

Jun Wang - One of the best experts on this subject based on the ideXlab platform.

  • on the Erosion Process on quartz crystals by the impact of multiple high velocity micro particles
    Tribology International, 2016
    Co-Authors: Huan Qi, Jun Wang, Huaizhong Li
    Abstract:

    Abstract A computational model using the discrete element method is presented to investigate the impact Process of multiple micro-particles on a quartz crystal. It is shown that the impacts initiate median and lateral cracks that degrade the strength of the substrate material and facilitate material removal in subsequent impacts. Elemental materials are removed through breaking their contacts with all adjacent elements by crack propagation and intersection. A larger overlapping impact condition between two impacts is more efficient for material removal in the second impact, but a total overlap does not yield the maximum material removal. The number of micro-cracks and the thickness of the cracked layer left on the eroded specimen are also studied in relation to the impact conditions.

  • particle velocity models for ultra high pressure abrasive waterjets
    Journal of Materials Processing Technology, 2009
    Co-Authors: Jun Wang
    Abstract:

    Particle velocity and trajectory in an ultra-high pressure abrasive waterjet (AWJ) are important jet characteristic information required for understanding and modelling the particle Erosion Process involved in AWJ machining. In this paper, mathematical models for the particle velocity variations across and along an AWJ are developed based on an in-depth understanding of the jet dynamic characteristics from a computational fluid dynamics (CFD) simulation study. The models are then assessed qualitatively and quantitatively. It is found that the model predictions are reasonable and consistent with the data from a verified CFD model with an average percentage error of less than 1%.

  • a preliminary study of the Erosion Process in micro machining of glasses with a low pressure slurry jet
    Key Engineering Materials, 2008
    Co-Authors: Thai Nguyen, King Lun Pang, Jun Wang
    Abstract:

    The Erosion Process in micro-machining of brittle glasses using a low pressure slurry jet is discussed. The Process capability of the technique is assessed by examining the machined surface integrity in relation to fluid flow dynamics in micro-hole generations. The holes produced are characterised by a “W” shape in the cross section, while the surface morphology is distinguished by three zones associated with the fluid flow behaviour, i.e. a direct impact zone, a wavy zone and an accumulation zone. The surfaces appear to be smooth and without cracks, indicating a predominance of the ductile mode Erosion Process. With the increase of pressure, the Erosion rates can be enhanced as a result of the expending of the accumulation zone while the outer diameter of the holes remains unchanged. This study shows that this technique can be used for micro-machining with high surface quality, and provides an essential understanding for further research in the avenue.

A. B. Tkhabisimov - One of the best experts on this subject based on the ideXlab platform.

  • experimental investigation into the Erosion wear of structural materials
    Thermal Engineering, 2014
    Co-Authors: Vyacheslavovich Artem Ryzhenkov, L I Seleznev, A. F. Mednikov, A. B. Tkhabisimov
    Abstract:

    Results of investigations into Erosion wear of Grade 20Kh13 steel with the collision velocity of rotating samples Vimp = 250 m/s with the particles of monodispersed erodent dd = 800 μm are considered. Substantial distinctions in the development of the Erosion Process of steel of the same brand subjected to the erodent effect with the same characteristics determined by accidental (unknown) circumstances are shown.

Lei Zhang - One of the best experts on this subject based on the ideXlab platform.

  • assessment of the impacts of soil Erosion on water environment based on the integration of soil Erosion Process and landscape pattern
    Journal of Applied Ecology, 2013
    Co-Authors: Bingfang Wu, Yuan Zeng, Lei Zhang
    Abstract:

    : The integration of the effects of landscape pattern to the assessment of the impacts of soil Erosion on eco-environmental is of practical significance in methodological prospect, being able to provide an approach for identifying water body's sediment source area, assessing the potential risks of sediment export of on-site soil Erosion to the target water body, and evaluating the capacity of regional landscape pattern in preventing soil loss. In this paper, the RUSLE model was applied to simulate the on-site soil Erosion rate. With the consideration of the soil retention potential of vegetation cover and topography, a quantitative assessment was conducted on the impacts of soil Erosion in the water source region of the middle route for South-to-North Water Transfer Project on rivers and reservoirs by delineating landscape pattern at point (or cell) scale and sub-watershed level. At point (or grid cell) scale, the index of soil Erosion impact intensity (I) was developed as an indicator of the potential risk of sediment export to the water bodies. At sub-watershed level, the landscape leakiness index (LI) was employed to indicate the sediment retention capacity of a given landscape pattern. The results revealed that integrating the information of landscape pattern and the indices of soil Erosion Process could spatially effectively reflect the impact intensity of in situ soil Erosion on water bodies. The LI was significantly exponentially correlated to the mean sediment retention capacity of landscape and the mean vegetation coverage of watershed, and the sediment yield at sub-watershed scale was significantly correlated to the LI in an exponential regression. It could be concluded that the approach of delineating landscape pattern based on soil Erosion Process and the integration of the information of landscape pattern with its soil retention potential could provide a new approach for the risk evaluation of soil Erosion.

Chuanzhen Huang - One of the best experts on this subject based on the ideXlab platform.

  • fem analysis on the abrasive Erosion Process in ultrasonic assisted abrasive waterjet machining
    The International Journal of Advanced Manufacturing Technology, 2015
    Co-Authors: Zhe Lv, Chuanzhen Huang
    Abstract:

    In this work, a finite element method (FEM) explicit dynamic simulation was employed to investigate the abrasive Erosion Process in ultrasonic-assisted abrasive waterjet (AWJ) machining. Johnson-Holmquist ceramic material model with failure criteria was utilized to realize the deletion of the failure elements for the simulation of material removal. The effects of impact angle and particle shape on the Erosion rate were analyzed. The residual stress in workpiece induced by the Erosion under the vibration condition was compared to that under the non-vibration condition. Furthermore, the ultrasonic-assisted Erosion Processes of multiple particles under different overlapping conditions on the impact areas were simulated. The simulation results show that the application of vibration can effectively improve the Erosion rate and influences the contact Process between the particle and the workpiece surface. The residual stress distribution in the section of workpiece parallel to the vibration direction is not symmetric under the vibration condition, which is quite different from the nearly symmetric one obtained without vibration.

  • an sph simulation on vibration assisted abrasive Erosion of hard brittle material in abrasive waterjet machining
    Advanced Materials Research, 2014
    Co-Authors: Zhe Lv, Chuanzhen Huang
    Abstract:

    Abrasive waterjet machining (AWJ) is one of the fastest growing non-conventional machining methods. However, low pressure and fine abrasive implemented in AWJ precision machining for reducing the surface damage reduce the efficiency. Therefore ultrasonic vibration is considered to apply on the workpiece to improve the machining efficiency. In order to analyze the effect of the vibration on Erosion in AWJ machining, smoothed particle hydrodynamics (SPH) is used to simulate the Erosion Process for avoiding the mesh distortion in finite element method (FEM) when simulating large deformation and high strain rate problems. The results show that the application of ultrasonic vibration can effectively improve the Erosion rate due to the dynamics variation of the Erosion Process.

  • experiment study on abrasive waterjet machining mechanisms of brittle materials
    Key Engineering Materials, 2008
    Co-Authors: Chuanzhen Huang, Quan Lai Li
    Abstract:

    The Erosion Process of abrasive waterjet (AWJ) on target material is very complicated and a complete clear understanding about material removal mechanisms in AWJ machining has not been obtained. In this paper, an experiment study on AWJ machining mechanisms of brittle materials is introduced so as to understand the actions of water jet and abrasive particle in material removal Process and some experiment evidences of the change of material removal mechanisms have been obtained.