Effect of Particle Impact Velocity on Cone Crack Shape in Ceramic Material

2005 ◽  
pp. 1321-1326
Author(s):  
Sang Yeob Oh ◽  
Hyung Seop Shin
Keyword(s):  
Ceramic Material ◽  
Impact Velocity ◽  
Particle Impact ◽  
Cone Crack ◽  
Crack Shape ◽  
Particle Impact Velocity

Effect of Particle Impact Velocity on Cone Crack Shape in Ceramic Material

2005 ◽  
Vol 297-300 ◽  
pp. 1321-1326 ◽  
Author(s):  
Sang Yeob Oh ◽  
Hyung Seop Shin
Keyword(s):  
Impact Velocity ◽  
Computational Simulation ◽  
Back Surface ◽  
Particle Impact ◽  
Cone Crack ◽  
Crack Shape ◽  
The Impact ◽  
Particle Impact Velocity ◽  
Sic Particle ◽  
Ring Cracks

The damage behaviors induced in a SiC by a spherical particle impact having a different material and size were investigated. Especially, the influence of the impact velocity of a particle on the cone crack shape developed was mainly discussed. The damage induced by a particle impact was different depending on the material and the size of a particle. The ring cracks on the surface of the specimen were multiplied by increasing the impact velocity of a particle. The steel particle impact produced the larger ring cracks than that of the SiC particle. In the case of the high velocity impact of the SiC particle, the radial cracks were generated due to the inelastic deformation at the impact site. In the case of the larger particle impact, the morphology of the damages developed were similar to the case of the smaller particle one, but a percussion cone was formed from the back surface of the specimen when the impact velocity exceeded a critical value. The zenithal angle of the cone cracks developed into the SiC decreased monotonically as the particle impact velocity increased. The size and material of a particle influenced more or less on the extent of the cone crack shape. An empirical equation was obtained as a function of impact velocity of the particle, based on the quasi-static zenithal angle of the cone crack. This equation will be helpful to the computational simulation of the residual strength in ceramic components damaged by the particle impact.

Experimental Investigation of the Location of Maximum Erosive Wear Damage in Elbows

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Quamrul H. Mazumder ◽  
Siamack A. Shirazi ◽  
Brenton McLaury
Keyword(s):  
Experimental Investigation ◽  
Mass Loss ◽  
Solid Particle ◽  
Impact Velocity ◽  
Single Phase ◽  
Erosive Wear ◽  
Particle Impact ◽  
Erosion Behavior ◽  
Wear Damage ◽  
Particle Impact Velocity

Erosive wear damage of elbows due to solid particle impact has been recognized as a significant problem in several fluid handling industries. Solid particle erosion is a complex phenomenon due to different parameters causing material removal from the metal surface. The particle density, size, shape, velocity, concentration, impact angle, and impacting surface material properties are some of the major parameters. Among the various factors, the particle impact velocity has the greatest influence in erosion. The particle impact velocity and impact angles depend on the fluid velocity and fluid properties. The particle to particle, particle to fluid, and particle to wall interactions increase the complexity of the erosive wear behavior. In multiphase flow, the presence of different fluids and their corresponding spatial distribution of the phases, adds another dimension to the problem. Most of the previous investigations were focused on determination of erosion in terms of mass loss of the eroding surfaces without identifying the specific location of the maximum erosive wear. During this investigation, magnitude of erosion at different location of an elbow specimen was measured to determine the location of maximum erosion. Experimental investigation of erosion in single-phase and multiphase flows was conducted at different fluid velocities. Both mass loss and thickness loss measurements were taken to characterize erosion behavior and erosion patterns in an elbow. Experimental results showed different erosion behavior and location of maximum erosion damage in single-phase and multiphase flows. The locations of maximum wear due to erosion were also different for horizontal flow compared to vertical flow.

Particle Velocity Measurements to Improve Erosion Prediction

Volume 3 ◽  
2004 ◽  
Author(s):  
Matthew J. Sampson ◽  
Siamack A. Shirazi ◽  
Brenton S. McLaury
Keyword(s):  
Impact Velocity ◽  
Particle Velocity ◽  
Particle Interaction ◽  
Particle Impact ◽  
Average Particle ◽  
Rotating Disks ◽  
Erosion Testing ◽  
Erosion Prediction ◽  
Particle Velocities ◽  
Particle Impact Velocity

Previous work on Computational Fluid Dynamics (CFD) based erosion modeling indicated a strong influence of particle impact velocity on erosion. Equations to predict erosion are based on particle impacting velocity, material properties and particle characteristics such as particle shape and size. Previous studies did not measure particle velocity directly but used rotating disks or simplified computer models to determine the particle velocity. In the present work, a series of experiments have been conducted to measure the velocity of small particles (sand and aluminum) as they approach a target. A laser Doppler velocimetry system was used to measure particle velocities in a jet of air as the jet impinges a target. The angle between the target and the incoming jet is varied. Particle concentration is also controlled, allowing the effects of particle to particle interaction on average particle impact velocity to be observed. These findings are expected to improve the results of erosion testing and provide new data for improving erosion models.

scholarly journals Study on performance degradation and damage modes of thin-film photovoltaic cell subjected to particle impact

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kailu Xiao ◽  
Xianqian Wu ◽  
Xuan Song ◽  
Jianhua Yuan ◽  
Wenyu Bai ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Conversion Efficiency ◽  
Photovoltaic Cell ◽  
Performance Degradation ◽  
Particle Impact ◽  
Laser Shock ◽  
Number Density ◽  
Mechanical Modeling ◽  
The Impact ◽  
Impact Experiments

AbstractIt has been a key issue for photovoltaic (PV) cells to survive under mechanical impacts by tiny dust. In this paper, the performance degradation and the damage behavior of PV cells subjected to massive dust impact are investigated using laser-shock driven particle impact experiments and mechanical modeling. The results show that the light-electricity conversion efficiency of the PV cells decreases with increasing the impact velocity and the particles’ number density. It drops from 26.7 to 3.9% with increasing the impact velocity from 40 to 185 m/s and the particles’ number densities from 35 to 150/mm2, showing a reduction up to 85.7% when being compared with the intact ones with the light-electricity conversion efficiency of 27.2%. A damage-induced conversion efficiency degradation (DCED) model is developed and validated by experiments, providing an effective method in predicting the performance degradation of PV cells under various dust impact conditions. Moreover, three damage modes, including damaged conducting grid lines, fractured PV cell surfaces, and the bending effects after impact are observed, and the corresponding strength of each mode is quantified by different mechanical theories.

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