CAJ | 학술논문

针对金属螺栓连接结构中螺栓孔位置处的裂纹损伤定量监测需求，在已有研究成果的基础之上，提出一种具有柔性平面特点的花萼状涡流阵列传感器，构建花萼状涡流阵列传感器裂纹扰动半解析模型，得到在三维结构裂纹下的传感器各感应通道扰动电压，并通过搭建实验装置验证裂纹扰动半解析模型的准确性。在模型构建过程中，通过对结构三维裂纹表面进行网格划分，以网格中心点处的自由电荷密度为未知待定系数，根据自由电荷边界条件以及扰动模型假设得到网格单元中心点处自由电荷密度所满足的线性方程组，并最终得到三维裂纹周围的自由电荷密度分布。裂纹扩展模拟实验结果表明，在3 MHz 和6 MHz 两种激励频率下，2A12-T4铝合金和不锈钢的扰动模型计算结果与实验测量结果比较吻合，传感器4个感应通道的扰动模型计算误差都在25%以内。
침대금속라전련접결구중라전공위치처적렬문손상정량감측수구，재이유연구성과적기출지상，제출일충구유유성평면특점적화악상와류진열전감기，구건화악상와류진열전감기렬문우동반해석모형，득도재삼유결구렬문하적전감기각감응통도우동전압，병통과탑건실험장치험증렬문우동반해석모형적준학성。재모형구건과정중，통과대결구삼유렬문표면진행망격화분，이망격중심점처적자유전하밀도위미지대정계수，근거자유전하변계조건이급우동모형가설득도망격단원중심점처자유전하밀도소만족적선성방정조，병최종득도삼유렬문주위적자유전하밀도분포。렬문확전모의실험결과표명，재3 MHz 화6 MHz 량충격려빈솔하，2A12-T4려합금화불수강적우동모형계산결과여실험측량결과비교문합，전감기4개감응통도적우동모형계산오차도재25%이내。
To monitor the crack damage located at the bolt hole of the metallic bolted-joint structure, based on the Ref. 18, the paper proposed a kind of rosette eddy current sensor with planar and flexible characteristics. Semi-analytical crack perturbation model of rosette eddy current sensors was constructed, and perturbation voltages of sensing channels under the three-dimension structural crack were obtained. Experiments were carried out to validate the model. During the model formulation, the surfaces of the three-dimension structural crack were meshed, and free charge density of each meshed cell center was defined as unknown parameter. According to the boundary condition of free charge and perturbation model assumption, the linear equations containing all unknown parameters were built, and the distribution of free charge density around the structural crack could be acquired via solving linear equations. The crack growth simulation experimental results show that perturbation models of 2A12-T4 aluminum alloy and stainless steel agree relatively well with experiment result under 3MHz and 6MHz stimulation frequencies, and perturbation model errors of four sensing channels are within 25 percent.