Effect of double holes on crack propagation in PMMA plates under blasting load by caustics method

2021 ◽  
Vol 116 ◽  
pp. 103103
Author(s):  
Chengxiao Li ◽  
Yiqiang Kang ◽  
Yuantong Zhang ◽  
Haohao Luo
Keyword(s):  
Crack Propagation ◽  
Caustics Method ◽  
Blasting Load

New crack generation phenomena by crack collision in 10 mm thick tempered glass

2021 ◽  
pp. 1-13
Author(s):  
Shin’ichi Aratani
Keyword(s):  
Tensile Stress ◽  
Crack Propagation ◽  
High Speed ◽  
Crack Tip ◽  
High Speed Photography ◽  
Tempered Glass ◽  
Crack Generation ◽  
Caustics Method ◽  
Thick Glass ◽  
Collision Angle

High speed photography by Caustics method using Cranz–Schardin camera was used to study crack propagation and divergence in thermally tempered glass. Tempered 10 mm thick glass plates were used as a specimen. New crack generation by two crack collision was observed. Regarding the presence/absence of new cracks, the dependence of the two cracks on the collision angle was confirmed. Considering that it is based on the synthesis of stress 𝜎CR generated at the crack tip, tensile stress necessary for the generation of new cracks could be created.

Crack propagation and divergence phenomena observed by Caustics method in tempered glass

2021 ◽  
pp. 1-18
Author(s):  
Shin’ichi Aratani
Keyword(s):  
Crack Propagation ◽  
High Speed ◽  
High Speed Photography ◽  
Tempered Glass ◽  
Glass Plates ◽  
The Difference ◽  
Caustics Method ◽  
Thick Glass

High speed photography by Caustics method using Cranz-Schardin camera was studied for crack propagation and divergence in thermally tempered glass. Tempered 10 mm thick glass plates were used as a specimen. Two types of bifurcation and branching as the crack divergence could be observed and clarified even in 10 mm thick tempered glass. The difference of the shadow spot sizes between bifurcation type and branching type could be confirmed.

scholarly journals Experimental Study on the Dynamic Behavior of Running Crack Affected by Defect Shape and Filling Material

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhen Lei ◽  
Mingsheng Zhao
Keyword(s):  
Crack Propagation ◽  
Silicone Rubber ◽  
Impact Loading ◽  
Experimental System ◽  
Filling Material ◽  
Propagation Behavior ◽  
Circular Defect ◽  
Caustics Method ◽  
The Impact ◽  
Crack Propagation Behavior

Using the caustics method and the experimental system of digital laser dynamic caustics, the model experiment of drop hammer impact loading was carried out, and the effect of the defect shape (circular and rectangular) and the filling material (air, epoxy, and silicone rubber) on the propagation behavior of the running crack was investigated. The experimental results show that, under the impact loading, the running crack initiates at the end of precrack and propagates toward the defect. After the running crack connects to the defect, it accumulates energy within a certain period before initiating again at the upper edge of the defect. Subsequently, only one running crack is formed at the upper edge of the circular defect, but two running cracks are formed at the upper edge of the rectangular defect. The defect shape and the filling material have a significant effect not only on the energy accumulation time of the running crack at the defect but also on the stress intensity factor when initiating at the defect. The effect degree of the defect shape on the running crack propagation behavior is in the following order: circular defect > rectangular defect, whereas the effect degree of the filling material on the running crack propagation behavior follows this order: air > silicone rubber > epoxy.

Mechanism of irregular crack-propagation in thermal controlled fracture of ceramics induced by microwave

2020 ◽  
Vol 21 (6) ◽  
pp. 610
Author(s):  
Xiaoliang Cheng ◽  
Chunyang Zhao ◽  
Hailong Wang ◽  
Yang Wang ◽  
Zhenlong Wang
Keyword(s):  
Crack Propagation ◽  
Industrial Application ◽  
Ceramic Materials ◽  
Advanced Technology ◽  
Analytical Models ◽  
Propagation Mechanism ◽  
Unstable Crack ◽  
Fracture Simulation ◽  
Initial Stage ◽  
Controlled Fracture

Microwave cutting glass and ceramics based on thermal controlled fracture method has gained much attention recently for its advantages in lower energy-consumption and higher efficiency than conventional processing method. However, the irregular crack-propagation is problematic in this procedure, which hinders the industrial application of this advanced technology. In this study, the irregular crack-propagation is summarized as the unstable propagation in the initial stage, the deviated propagation in the middle stage, and the non-penetrating propagation in the end segment based on experimental work. Method for predicting the unstable propagation in the initial stage has been developed by combining analytical models with thermal-fracture simulation. Experimental results show good agreement with the prediction results, and the relative deviation between them can be <5% in cutting of some ceramics. The mechanism of deviated propagation and the non-penetrating propagation have been revealed by simulation and theoretical analysis. Since this study provides effective methods to predict unstable crack-propagation in the initial stage and understand the irregular propagation mechanism in the whole crack-propagation stage in microwave cutting ceramics, it is of great significance to the industrial application of thermal controlled fracture method for cutting ceramic materials using microwave.

High Cycle Fatigue and Fatigue Crack Propagation Behaviors of Modified A7075-T73 Alloy

2014 ◽  
Vol 52 (4) ◽  
pp. 283-291 ◽  
Author(s):  
Gwan Yeong Kim ◽  
Kyu Sik Kim ◽  
Joong Cheol Park ◽  
Shae Kwang Kim ◽  
Young Ok Yoon ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
High Cycle Fatigue ◽  
Cycle Fatigue
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