Vibration evaluation and repair strategy of damaged blisks

Title of the research project

BRAVO: Establishing Blend Repair limit of blisks –from A perspective of Vibration amplification

Scientific area 

Aerospace engineering, structural dynamics, dynamic testing

Marie Curie fellow 

Biao Zhou


Blisks extensively used in the fan/compressor sections of advanced aeroengines, are vulnerable to inevitable blade damages. BRAVO aims to develop a comprehensive vibration evaluation tool that can portray the risks and benefits of repairing a damaged blisk by the cost-effective blending operations.

Description of the research project 

An efficient maintenance of the extremely expensive blisks in aeroengines of last generation requires that damaged blades can be cost-effectively repaired without loose of reliability. The “blending” is a typical repair process where the damaged area of the blade is blending out. However, there still a limited understanding of the blending effect on the forced response of the blisk. The challenge is the determination of the rational of the blend limits, i.e., the maximum allowable size, location and number of blends in a repaired blisk.

BRAVO proposes a comprehensive vibration evaluation tool that can foresee the risks and benefits of blending a damaged blisk. The starting point is the 3D optical geometry scanning technology so that geometry variances due to both blends and intrinsic blade geometric deviations can be effectively accounted for. The developed tool will allow to define the effect of blending and the limits of this technique, in order to repair a large number of damaged blisks, reducing the risk of failure.

This project involves interdisciplinary expertise in structural dynamics of blisks, aerodynamics of cascades, high precision blade geometry measurements and advanced blade vibration testing technologies.

POLITO’s research capability and testing facilities in the field of dynamics of bladed disk, will give a solid foundation to assure the accomplishment of this project.

Impact on fellow career and on society 

The interdisciplinary nature of this cutting-edge project BRAVO will stimulate the research fellow’s scientific creativity and passion for pursuing new engineering knowledge and techniques in the field of structural dynamics and dynamic testing. With deepened competence in both technical and transferable skills, the research fellow will reach a high level of professional maturity and scientific independence.

The methods and tools developed in BRAVO respond to the need of improving design and maintenance techniques in aeroengines industry in Europe increasing the safety of aeroengines.


Short CV of Marie Curie fellow 

Biao Zhou is an associate professor in structural dynamics from Nanjing University of Aeronautics and Astronautics, China. He received his Bachelor and Master’s degree in 2007 and 2009 at Beijing University of Aeronautics and Astronautics, China. He holds a PhD’s degree in the Laboratoire de Tribologie et Dynamique des Système, Ecole Centrale de Lyon, France (2009-2013).



Teresa Maria Berruti, DIMEAS - Dipartimento di Ingegneria Meccanica e Aerospaziale

BRAVO project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 891197

  • Budget: 183.473 euro
  • Start date: 1/05/2021
  • End date: 30/04/2023