Data for a publication - Measuring Device for More Precise Mistuning Identification of Integrated Bladed Discs

In integrated turbine wheel designs, small deviations, known as mistuning, often occur in the modal properties of individual blades due to manufacturing tolerances and material inhomogeneity. During operation, this mistuning can cause some rotor blades to be subjected to significantly higher loads than predicted for an ideal rotor. The degree of rotor mistuning can only be determined using methods of experimental modal analysis. However, the manual use of the modal hammer cannot ensure precise repeatability of the force impulse’s location and timing, leading to inaccuracies. This article introduces a mechanism that replaces manual modal hammer operations, guaranteeing consistent impact location and timing while eliminating double strikes. The device was verified on bladed discs of various sizes, and its usability is demonstrated in this article on a turbine wheel of a marine engine turbocharger. The developed mechanism automates modal hammer strikes, ensuring precisely repeatable force courses and positioning for each impact. This automation reduces the measurement time and significantly improves the accuracy. The results of this research showed that even with careful manual operation of the modal hammer by an experienced operator, statistically significant differences arise in the repeated measurements of a bladed disc mistuning, whereas with the use of the presented measuring device, the results of the repeated measurements are practically identical.在整体式涡轮轮盘的设计中，受制造公差与材料不均匀性的影响，单个叶片的模态特性往往会产生微小偏差，这类偏差被称为失谐（mistuning）。设备运行过程中，该失谐现象会使部分转子叶片承受的载荷远高于理想转子的预测值。转子失谐程度仅可通过实验模态分析方法进行测定。然而，手动操作模态锤（modal hammer）无法确保力脉冲的位置与时刻具备精确的可重复性，从而引入测量误差。本文介绍了一种可替代手动模态锤作业的机械装置，该装置能够保证冲击位置与时刻保持一致，同时避免重复冲击。研究团队针对多种尺寸的带叶片盘对该装置开展了验证工作，并以船用发动机涡轮增压器的涡轮轮盘为例，展示了该装置的实用价值。所开发的机械装置实现了模态锤敲击的自动化，可确保每次敲击的力历程与定位精度均具备可重复性。该自动化操作缩短了测量时长，同时显著提升了测量精度。本研究结果显示，即便由经验丰富的操作人员手动操作模态锤，在对带叶片盘的失谐进行重复测量时，仍会出现统计学意义上的显著差异；而采用本文所提出的测量装置后，重复测量的结果几乎完全一致。