Experimental Validation of a Mesh Quality Optimized Morphed Geometric Mistuning Model

Abstract

High cycle fatigue due to mode localization caused by geometric and material mistuning is one of the leading failure risks of integrally bladed rotors (IBRs). Due to the computational analysis cost of full wheel models, IBR mistuned response amplifications are often modeled with reduced order models (ROMs). However, many developed ROMs are based on nominal mode assumptions that do not consider mode shape variations that have been shown to impact predicted mistuned response. Geometrically mistuned finite element models (FEMs) do account for mode shape variations but are notoriously difficult to construct and analyze. Recent advancements in optical scanning have enabled the rapid acquisition of highly accurate dense point clouds representative of manufactured hardware. Previous research pioneered a novel method to automatically and robustly construct an FEM directly from tessellated scan data, this research adds new mesh quality verification algorithms and experimentally validates this algorithm using results from traveling wave excitation. Sensitivity to mesh and point cloud density are also assessed to determine a best practice for creation of the as manufactured mistuned rotor model.