受火后混凝土表面损伤超声波检测算法

Ultrasonic Testing Algorithm to the Surface Damage of Fire-Damaged Concrete

受火后混凝土损伤厚度的超声波检测中,通常简单地将混凝土假定为受损层和未受损层,以超声波检测数据(声时-测距的双折线模型)来理论计算混凝土的受损深度。这种方法简单、便捷,但在实际应用中误差较大。研究了基于混凝土受损趋势为双曲线模型的假定,以首波传播路径为抛物线的改进算法。借助ABAQUS有限元软件模拟了声波在受损混凝土中的传播,对改进算法进行了验证。有限元模拟表明,该改进算法具有较高的计算精度,更符合实际情况。

Ultrasonic method is usually used to test the depth of fire-damaged concrete.It is assumed that the structural members could be simply classified into damaged layer and undamaged layer in the concrete and the damage depth can be calculated with a series of single-sided ultrasonic measured data.This method is simple and convenient but has a less precision in the practical application.A new improved algorithm was introduced in this paper.It is based on the assumption that the damage model was hyperbolic and the propagation path of the first wave was parabola.ABAQUS finite element analysis software was used to simulate the ultrasonic wave propagation in the damaged concrete for theoretical proof of the improved algorithm.The result showed this improved algorithm owned higher accuracy and better feasibility.