【摘要】 在使用激光器切割液晶玻璃过程中,时常会碰到边缘质量问题.从断裂力学的角度,运用实验和数值模拟的方法,探讨了激光扫描速度对裂纹尖端应力强度因子的影响,研究了玻璃表面边缘质量缺陷问题、裂纹偏转角以及裂纹扩展到分叉点时的应力强度因子变化.结果表明:仅增加激光扫描速度2mm/s,对裂纹尖端I型和II型应力强度因子的降低就非常明显;裂纹表面边缘的气泡以及缺陷是由于激光扫描过程中局部温度达到玻璃软化温度造成的;裂纹的偏转角符合最大周向应力准则;裂纹分叉点的应力强度因子大小已超过玻璃断裂韧度,而且在扩展到分叉点过程中,应力强度因子KII的作用呈不断增大现象.更多还原

【Abstract】 The edge of liquid crystal glass often crack during the cutting process with laser.The influence of laser scanning speed on the stress intensity factor is discussed.It has also been studied that surface defects in liquid crystal glass,the direction of crack propagation and stress intensity factor of crack branch point.These procedures are illustrated with experimental tests and numerical simulation.As the result,the stress intensity factor of crack tip can be reduced significantly by increasing laser scanning speeds;because of local temperature reaching the softening temperature of the glass in laser scanning process,bubbles and defects are generated on the edge of glass surface;crack deflection angle under mixed mode loading(modeⅠandⅡ)is in line with the maximum circumferential stress criterion;the stress intensity factor of crack tip has reached the fracture toughness and stress intensity factor KII(mode II)is increased with crack propagating.更多还原