DOI:
https://doi.org/10.14483/23448393.22926Published:
2025-08-01Issue:
Vol. 30 No. 2 (2025): May-AugustSection:
Mechanical EngineeringTheoretical-Experimental Modal Analysis of a Flexible Rotor Based on the Jeffcott Model
Análisis modal teórico-experimental de un rotor flexible basado en el modelo de Jeffcott
Keywords:
MAC, vibration mode shapes, flexible rotors, Jeffcott rotor, Experimental Modal Analysis, Theoretical Modal Analysis, natural frequencies (en).Keywords:
Análisis Modal Experimental, Análisis Modal Teórico, frecuencias naturales, MAC, modos de vibración, rotores flexibles, rotor de Jeffcott (es).Downloads
Abstract (en)
Context: Rotating equipment that operates at high speeds or handles significant loads is designed based on the concept of flexible shafts. This is the case with turbines, compressors, and turbopumps, among others. The theoretical-experimental modal analysis of these shafts is crucial for ensuring a safe and efficient operation, as well as for identifying appropriate maintenance strategies.
Method: In this work, we perform both theoretical and experimental modal analyses of an isotropic flexible rotor based on the Jeffcott model. The theoretical modal analysis is carried out using a numerical model with conditions similar to those of the experimental analysis. The results are compared using the modal assurance criterion (MAC). The validated numerical model enables the evaluation of eigenfrequencies and their associated modal shapes.
Results: The first two bending natural modes of the flexible rotor were obtained from the theoretical and experimental modal analysis, and the mode shapes and natural frequencies were determined. The mode shapes were correlated, exhibiting a correlation value greater than 88%, thus validating the numerical model.
Conclusions: This approach not only enhances the understanding of the shaft’s dynamic response but also contributes to improved decision-making during the design and operation stages of rotating systems in various industrial applications.
Abstract (es)
Contexto: El equipo rotativo que opera a altas velocidades o maneja cargas significativas se diseña con base en el concepto de ejes flexibles. Este es el caso de las turbinas, los compresores y las turbobombas, entre otros. El análisis modal teórico-experimental de estos ejes es esencial para garantizar una operación segura y eficiente, así como para identificar estrategias de mantenimiento adecuadas.
Método: En este trabajo desarrollamos análisis modales tanto teóricos como experimentales de un rotor flexible isotrópico basado en el modelo de Jeffcott. El análisis modal teórico se realiza utilizando un modelo numérico con condiciones similares a las del análisis experimental. Los resultados se comparan utilizando el criterio de aseguramiento modal (MAC). El modelo numérico validado permite evaluar las frecuencias propias y sus formas modales asociadas.
Resultados: Se obtuvieron los dos primeros modos naturales de flexión del rotor flexible del análisis modal teórico y experimental, y se determinaron las formas modales y las frecuencias naturales. Las formas modales estuvieron correlacionadas, obteniendo un valor de correlación superior al 88 %, lo que valida el modelo numérico.
Conclusiones: Este enfoque no solo mejora la comprensión de la respuesta dinámica del eje, sino que también contribuye a mejorar la toma de decisiones durante las etapas de diseño y operación de sistemas rotativos en diversas aplicaciones industriales.
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Copyright (c) 2025 Javier Ruíz-Rodríguez, Brian Farid Morales-Hernández, Heller Guillermo Sánchez-Acevedo
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