scholarly journals Simulation Analysis of Cluster Effect of High-Shear Low-Pressure Grinding with Flexible Abrasive Tools

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 827
Author(s):  
Chengjin Tian ◽  
Jinguo Han ◽  
Yebing Tian ◽  
Bing Liu ◽  
Zhiqiang Gu ◽  
...  

Based on the clustering effect of shear-thickening fluids (STFs), a high-shear low-pressure flexible grinding wheel has been developed. In order to explore the material removal mechanism, the coupled Eulerian—Lagrangian (CEL) method is adopted to simulate the novel grinding process. The simulation results show that particle clustering effects do occur at the tangential and bottom positions of the micro-convex peak when it instantaneously strikes the workpiece surface. The particle clusters drive the harder abrasive particles to resist the strong interactions of micro-convex peaks. The micro-convex peaks are removed due to the cutting effect of the harder abrasive particles. Compared with traditional grinding, the ratio of tangential force to normal force for the high-shear low-pressure flexible grinding wheel is improved. The various trends in force ratio are consistent with the experimental results, which verifies the effectiveness of high-shear low-pressure grinding.

Author(s):  
Yebing Tian ◽  
Linguang Li ◽  
Shuo Fan ◽  
Qianjian Guo ◽  
Xiang Cheng

In this work, a novel grinding method using a special abrasive tool was first proposed to achieve high tangential grinding force and low normal grinding force. The abrasive tool was developed with flexible composites to remove workpiece materials under “high-shear and low-pressure” grinding mode. The concept of the high-shear and low-pressure grinding method was introduced in detail. Grinding tests were carried out on a precision grinder with the developed abrasive tool for single crystal silicon specimens. The results showed that the grinding force ratio between tangential force and normal force for the proposed grinding method was ranged between 0.9 and 1.3, which was three times larger than that of the conventional grinding method. It was verified that the developed abrasive tool possessed the grinding characteristics of high tangential grinding force and low normal grinding force. After grinding of silicon specimens for 120 min, the value of surface roughness decreased from 429.20 to 32.91 nm under the selected grinding conditions. The surface quality of the silicon specimens was greatly improved after grinding.


Author(s):  
Li Chang ◽  
Ziyan Man ◽  
Lin Ye

This paper reported the new polishing technique by using a shear thickening fluid (STF). In experiments, the steel workpiece was immersed into the STF under the static condition. When the workpiece started rotating at a certain speed, the surrounding STF became solidified due to the shear thickening effect. Consequently, the solidified STF held the abrasive particles and polished the surfaces of the workpiece. The surface roughness of the treated surfaces was clearly dependent on the size of the abrasive particles. Owing to the reversible phase transition between liquid and solid status for the STF, the polishing process can be conducted without the use of polishing pads. Moreover, the new polishing technique using the STF can polish some complex structures having the surfaces with different heights and/or orientations, which cannot be achieved by the traditional one-step polishing method.


2016 ◽  
Vol 1136 ◽  
pp. 78-83
Author(s):  
Anand Nambiar ◽  
Kou Matsumoto ◽  
Masaru Yamamoto ◽  
Kazuhito Ohashi ◽  
Shinya Tsukamoto

While grinding with CNC cylindrical grinding machines, there are many factors that determine the precision and accuracy of the finished product. These may include dimensional accuracy, surface roughness, circularity (roundness), cylindricity, etc. But all these factors pertain to the work. The condition of the tool, in this case, the cutting edges of the grinding wheel, also greatly influence the profile and precision of the work. So, in order to maintain the precision of the work, there is a need to repeatedly and regularly maintain the cutting edges in a good cutting condition, by the process of dressing. In other words, when the swarf gets adhered to the grinding wheel, the abrasive particles can no longer perform machining with the same efficiency, due to increase in contact surface area between the abrasive particles and the work. This dissertation describes a technique that can be adopted to continuously monitor the grinding forces generated during the grinding operation, by using an in-process 2-dimensional piezoelectric force sensor, which can simultaneously measure the force and break it down into its two force components. The force sensor not only calculates the force generated, but also quantifies the force variation. By analyzing the variation in the radial and tangential force components individually, and by conducting Fourier analysis on the observed data, it is found that deterioration of the grinding wheel and the dress pattern can be continuously monitored and controlled.


2011 ◽  
Vol 4 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Jie Ding ◽  
Weihua Li ◽  
Shirley Z. Shen

2021 ◽  
pp. 002199832098424
Author(s):  
Mohsen Jeddi ◽  
Mojtaba Yazdani

Whereas most previous studies have focused on improving the penetration resistance of Shear Thickening Fluids (STFs) treated composites, in this study, the dynamic compressive response of single and multi-ply 3 D E-Glass Fiber Reinforced Polymer (GFRP) composites with the STF matrix was investigated by using a drop-weight low-velocity impact test. The experimental results revealed the STF improved the compressive and cushioning performance of the composites such that with increasing its concentration, further improvement was observed. The five-ply composite containing the STF of 30 wt% silica nanoparticles and 1 wt% carbon nanotubes (CNTs) reduced the applied peak force by 56% and 26% compared to a steel plate and five-ply neat samples, respectively. A series of repeated impacts was performed, and it was found that the performance of high-concentration composites is further decreased under this type of loading.


2007 ◽  
Vol 46 (8) ◽  
pp. 1099-1108 ◽  
Author(s):  
Christian Fischer ◽  
Christopher J. G. Plummer ◽  
Véronique Michaud ◽  
Pierre-Etienne Bourban ◽  
Jan-Anders E. Månson

Author(s):  
Nariman Ashrafi ◽  
Habib Karimi Haghighi

The effects of nonlinearities on the stability are explored for shear thickening fluids in the narrow-gap limit of the Taylor-Couette flow. It is assumed that shear-thickening fluids behave exactly as opposite of shear thinning ones. A dynamical system is obtained from the conservation of mass and momentum equations which include nonlinear terms in velocity components due to the shear-dependent viscosity. It is found that the critical Taylor number, corresponding to the loss of stability of Couette flow becomes higher as the shear-thickening effects increases. Similar to the shear thinning case, the Taylor vortex structure emerges in the shear thickening flow, however they quickly disappear thus bringing the flow back to the purely azimuthal flow. Naturally, one expects shear thickening fluids to result in inverse dynamical behavior of shear thinning fluids. This study proves that this is not the case for every point on the bifurcation diagram.


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