用含有预制半圆形三维表面裂纹的冷冻透明有机玻璃材料研究了裂纹的扩展机制,并对裂纹扩展中的特征应力进行了分析,同时,考察了裂纹深度、长度和倾角等几何因素变化对裂纹扩展的影响。研究结果表明,表面裂纹扩展受裂纹深度 d 与试样厚度...用含有预制半圆形三维表面裂纹的冷冻透明有机玻璃材料研究了裂纹的扩展机制,并对裂纹扩展中的特征应力进行了分析,同时,考察了裂纹深度、长度和倾角等几何因素变化对裂纹扩展的影响。研究结果表明,表面裂纹扩展受裂纹深度 d 与试样厚度 T 影响很大,当 d/T≥1/3时,表面裂纹扩展到接近试样端部并穿透到试样的背面,当 d/T<1/3时,其裂纹扩展长度为预制裂纹直径的0.5~1倍时就不再扩展;裂纹倾角和裂纹相对试样尺寸也影响裂纹扩展。展开更多
Breakage, comminution, crushing and fragmentation of brittle solids under dynamic impacts are an important applied mechanics and rock mechanics problem. In civil engineering applications, impact-induced-fragmentation ...Breakage, comminution, crushing and fragmentation of brittle solids under dynamic impacts are an important applied mechanics and rock mechanics problem. In civil engineering applications, impact-induced-fragmentation relates to crushing of rock mass during mining process, tunneling, and aggregate production. The main objective of this paper is to outline some of our recent experimental, analytical and numerical efforts in studying the dynamic fragmentation process in brittle particle. First, an analytical solution of a solid sphere compressed dynamically between two rigid flat platens is derived analytically. Secondly, a sequence of double impact tests on spheres were conducted using an impactor Dynatup 8250 at HKUST, with both impact velocity and contact force at the impactor measured accurately. Finally, a newly developed computer program, DIFAR, is used to investigate the mechanism of dynamic fragmentation. The paper will summarize and discuss briefly all three aspects of our comprehensive approach.展开更多
文摘用含有预制半圆形三维表面裂纹的冷冻透明有机玻璃材料研究了裂纹的扩展机制,并对裂纹扩展中的特征应力进行了分析,同时,考察了裂纹深度、长度和倾角等几何因素变化对裂纹扩展的影响。研究结果表明,表面裂纹扩展受裂纹深度 d 与试样厚度 T 影响很大,当 d/T≥1/3时,表面裂纹扩展到接近试样端部并穿透到试样的背面,当 d/T<1/3时,其裂纹扩展长度为预制裂纹直径的0.5~1倍时就不再扩展;裂纹倾角和裂纹相对试样尺寸也影响裂纹扩展。
文摘Breakage, comminution, crushing and fragmentation of brittle solids under dynamic impacts are an important applied mechanics and rock mechanics problem. In civil engineering applications, impact-induced-fragmentation relates to crushing of rock mass during mining process, tunneling, and aggregate production. The main objective of this paper is to outline some of our recent experimental, analytical and numerical efforts in studying the dynamic fragmentation process in brittle particle. First, an analytical solution of a solid sphere compressed dynamically between two rigid flat platens is derived analytically. Secondly, a sequence of double impact tests on spheres were conducted using an impactor Dynatup 8250 at HKUST, with both impact velocity and contact force at the impactor measured accurately. Finally, a newly developed computer program, DIFAR, is used to investigate the mechanism of dynamic fragmentation. The paper will summarize and discuss briefly all three aspects of our comprehensive approach.