The paper presents analytical and numerical methods based on finite element modeling for determining vibrodiagnostic indicators of the presence of a transverse edge crack closing in a cantilever composite beam made of orthotropic material. The results of studies of the effect of its presence on the change in the main vibration frequency and on the ratio of the amplitudes of the dominant harmonics at the main, superharmonic order 1/2, and subharmonic order 2 resonances are presented. It has been shown that for a composite beam reinforced in the bending plane with unidirectional fibers with their laying angles relative to the axis of 0...40°, it is advisable to use the change in the natural vibration frequency as a vibration diagnostic indicator, and for larger angles, the ratio of the amplitudes of the dominant harmonics at super- and subharmonic resonances may be of practical importance.

本文提出了基于有限元建模的分析和数值方法，用于确定由正交各向异性材料制成的悬臂组合梁中是否存在横向边缘裂纹闭合的振动诊断指标。介绍了其存在对主振动频率变化以及主、超谐波 1/2 和分谐波 2 阶谐振的主要谐波振幅比的影响的研究结果。已经表明，对于在弯曲平面上用单向纤维加固且相对于轴线的铺设角度为 0...40° 的组合梁，建议使用固有振动频率的变化作为振动诊断指标，并且对于较大的角度，超谐波和次谐波谐振的主谐波的振幅之比可能具有实际重要性。