纤维混凝土试件拉伸损伤声发射监测

研究不同纤维长度和掺量的水泥基复合材料拉伸实验,材料内部微结构破坏的声发射特性。结果表明,加载初期,拉应力较小,试件处于弹性阶段,混凝土内部没有新增损伤,故未接收到声发射信号;加载中期,随着拉应力的增大,混凝土内部出现较少损伤,声发射信号逐渐增多;加载后期,拉应力继续增大,混凝土内部损伤程度加大,声发射信号急剧增加,至试件断裂时,声发射信号达到最大。相应的纤维混凝土断裂过程包括:弹性阶段、开裂阶段、裂缝发展阶段、断裂阶段。

Acoustic Emission Monitoring of Tensile Damages of Fiber Concrete

Acoustic emission(AE)testing technique is used to monitor the interior micro-structure crack acoustic characteristic of fiber cement based composite material with different length and admixing quantity in tensile test.The results indicate that: during the initial loading stage,test specimen is under elastic state and there is no new addition damage,so no acoustic emission signal is received;during the middle loading stage,with the accretion tension stresses,damage appears and acoustic emission signal multiplies gradually;during the end loading stage,with the accretion tension stresses further,the damage degree of concrete increase and acoustic emission signal increases rapidly till the fracturation of specimen,and the emission signal achieve the most.The failure process of fiber concrete is:elastic stage,crack stage,crack development stage and fracturation stage.