【摘要】 在含裂纹的A3钢试件拉伸断裂过程中,采用红外热像仪监测其拉伸断裂行为,并基于热像序列计算出裂纹扩展中的热耗散速率;跟踪裂纹前端最高温度点,测量出裂纹扩展长度。根据热力学理论讨论了温度变化与构件力学行为之间的联系。研究结果表明,裂纹试件在拉伸断裂过程中的温度曲线包括5个阶段:扩展前平稳阶段、波动升温阶段、稳定升温阶段、失效前迅速升温阶段和失效后降温阶段。温度的变化描述了构件的力学行为,揭示了构件的损伤规律。更多还原

【Abstract】 An infrared thermography camera was used for nondestructive evaluation of cracked specimens by monitoring the temperature evolutions during tensile fracture experiments.Heat dissipation rate during crack growth was calculated based on thermographic sequences.By tracking the peak temperature ahead of crack tip,the crack length was measured.On the basis of thermomechanics theory,the relationship between the temperature and mechanical behavior was discussed,and the damage mechanism of the cracked specimen was revealed.Five stages of temperature profiles were observed: an equilibrium temperature before propagation,a fluctuant increase of the crack tip temperature,a steady increase of temperature,an abrupt increase of temperature,and a drop of temperature following specimen failure.更多还原