【摘要】 裂缝深度检测的超声波首波相位反转法凭借其准确、简单、易操作的优点，被广泛应用于建设工程质量检测领域，结合理论分析、数值模拟和试验验证研究了其相位反转的成因。结果表明，相位反转现象是衍射纵波存在衍射相位反转角所致；在衍射相位反转角附近，衍射纵波的振幅呈现出先减小后增大的变化特征。对首波相位反转法完整且正确的解释，可为其应用提供理论基础及更有力的数据支撑。更多还原

【Abstract】 Ultrasonic first-pulse phase reverse is widely used in the field of construction engineering quality inspection due to its accuracy, simplicity and easy operation.Combining theoretical analysis, numerical simulation and experimental verification, the causes of phase reverse is studied. The research results show that the phase reversal phenomenon is caused by the diffracted phase reversal angle of the diffracted longitudinal wave; near the diffracted phase reversal angle, the amplitude of the first-pulse decreases first and then increases. As a result, ultrasonic first-pulse phase reverse has been completely and correctly explained, which provides a theoretical reference and more powerful data support for its application.更多还原