Abstract: Contacts among ultrasonic horn and surface of CFRP complex structure were line contacts. During excitation and detection, coupling efficiency was low, and contact stress was concentrated, while secondary damage occurred easily. Based on Huygens principle and dual-source interference enhancement effect, a design method for surface-contact dual-source excitation energy steering device was propose herein. A finite element model was established by ABAQUS. Influences of different excitation device size and excitation methods on temperature rise of the tube damages were analyzed. Design parameters of the curved dual-source device was determined, and a control experiment for the excitation device was set up to verify the pararneters. The results show that the maximum temperature rise of crack damages is increased by about 35.8%, and the curved dual-source excitation device may avoid stress concentration and effectively reduce risk of secondary damages.

Key words: ultrasonic thermography, carbon fiber reinforced polymer(CFRP), surface contact, crack, impact damage of laminate

摘要： 超声变幅杆与碳纤维复合材料复杂结构件表面的接触为线接触，激励检测时，耦合效率低、接触应力集中，易出现二次损伤。基于惠更斯原理及双源干涉增强效应，提出一种面接触双源激励能量导向装置设计方法。使用ABAQUS建立有限元模型，分析激励装置尺寸及激励方式对圆管损伤温升的影响，确定了曲面双源装置设计参数，并进行了实验验证。实验结果表明，裂纹损伤最大温升增幅约为35.8%，曲面双源激励装置能够避免应力集中，有效降低二次损伤风险。

关键词: 超声红外热成像, 碳纤维复合材料, 面接触, 裂纹, 层合板冲击损伤