Results of a work on evaluation of the effectiveness of promising vibration diagnostic technologies on the basis of an operating helicopter with an experimental system for monitoring the state of structures are presented. To move towards a practical application of the monitoring system based on the Operational Modal Analysis (OMA), it is necessary to assess its ability to distinguish actual defects. This problem was solved in a practical way as applied to a composite blade rotating together with the rotor of an operating helicopter. To assess the effect of a defect on the modal properties of the blade, a numerical modeling was performed, where changes in two modal parameters, the frequency and shape of each of M modes, were calculated. The influence of a test defect was assessed by comparing the modal properties of the damaged blade model with those in its reference state. The defect model corresponded to the planned full-scale defect of the blade in the form of a through hole in its tail part. Based on simulation results, requirements to the system for measuring and processing data, as well as to conditions for conducting an experiment to assess the resolution of the system, are formulated.

提出了基于正在运行的直升机以及用于监视结构状态的实验系统，对有前途的振动诊断技术的有效性进行评估的工作结果。为了使基于操作模态分析（OMA）的监视系统的实际应用成为现实，有必要评估其区分实际缺陷的能力。该问题以实用的方式解决了，该问题适用于与运行中的直升机的旋翼一起旋转的复合叶片。为了评估缺陷对叶片模态特性的影响，进行了数值建模，计算了两个模态参数（每个模态的频率和形状）的变化。通过将损坏的叶片模型的模态特性与参考状态下的模态特性进行比较，可以评估测试缺陷的影响。缺陷模型以叶片尾部的通孔形式对应于计划的叶片全尺寸缺陷。基于仿真结果，制定了对用于测量和处理数据的系统的要求，以及对进行实验以评估系统分辨率的条件的要求。