由于线性超声波法对混凝土早期应力不敏感，而非线性超声谐波法可以反映材料裂纹及应力演化特征，提出了基于非线性超声谐波效应的混凝土应力检测方法。该方法利用混凝土材料裂纹演化与超声波非线性二次谐波效应的关系，建立了混凝土轴向应力与非线性响应声学参数的本构关系模型，明确了其主要影响参数。最后通过混凝土标准试样的超声谐波应力检测试验，将所得结果与本构模型进行了对比分析，验证了提出的检测方法的有效性，为工程上混凝土的应力检测提供参考依据。

A concrete stress detection method based on nonlinear ultrasonic harmonic effects was proposed in this paper. Since the linear ultrasonic method is not sensitive to early stress of concrete and the nonlinear ultrasonic harmonic method can better reflect the characteristics of material cracks and stress evolutions. First, a constitutive model for the axial stress of concrete and its acoustic parameters of nonlinear response were established by using the relationship between the crack evolution of concrete material and the nonlinear second-harmonic effect of ultrasonic waves. Then the main influencing parameters of this method were clarified. Lastly, the ultrasonic harmonic stress detection tests for concrete standard specimens were carried out and a comparative analysis with the textual model was made to verify the effectiveness of the proposed detection method. The results may provide a reference for concrete stress detection in engineering.