New nonlinear design for cyclic symmetric structures

9 Mar 2024
Job Information

Organisation/Company

Ecole centrale de Lyon

Research Field

Engineering

Researcher Profile

Recognised Researcher (R2)
Leading Researcher (R4)
First Stage Researcher (R1)
Established Researcher (R3)

Country

France

Application Deadline

30 Jun 2024 – 22:00 (UTC)

Type of Contract

Temporary

Job Status

Full-time

Offer Starting Date

1 Jul 2024

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

The society is currently facing the paradox of an ever more interconnecting world and its need to decrease the pollution to protect the environment. In this context, European authorities have defined specific goals for aeronautical companies. In the short-term planning, they must decrease carbon emission and noise pollution. The proposed work is in line with the ecological goals and aims to be a pioneer for the 2050 target, which is carbon neutrality. These formidable challenges require a new vision of designing airplanes engines.
            
            In order to reduce fuel consumption, designers aim to increase the bypass ratio of the engines. Thanks to the developments of composite materials, fan systems have become larger while maintaining a slender profile. However, the intrinsic geometrical effects become more pronounced, leading to a nonlinear dynamic behavior. One of the main features of nonlinear system is that multiple stable solutions can coexist. This project thus aims to find these new solutions and design the system to make them advantageous in term of vibration attenuation.
            
            Complex dynamic behaviors (internal resonances, subharmonic interaction, and so on) arise in nonlinear systems. Different kinds of solution may exist : stable/unstable, periodic, quasiperiodic, and chaotic. Bringing new insights into these behaviors will enable using these nonlinearities for energy transfer between the modes, and thus aiming for a global energy reduction.

This project aims to propose new design of cyclic symmetric structures using wisely the intrinsic nonlinearities to decrease the vibration levels. To achieve this, it is mandatory to compute all periodic solutions of the systems, to characterize them and follow their evolution. The outline of the project is the following
1) Carry out an extensive literature review of the different analytical and numerical methods and evaluate their respective efficiency.
2) Apply and adapt the most promising strategy to cyclic symmetric structures
3) Low dimension system will be initially investigated before large scale systems.
4) Find, on an experimental setup, the solutions (isolas, bifurcations, etc).

Funding category: Financement public/privé

PHD title: PhD in structural dynamics
PHD Country: France

Requirements
Specific Requirements

Knowledges in nonlinear dynamics, applied mathematics
Programming softwares: Python, Matlab
Languages : English

Additional Information
Work Location(s)

Number of offers available

1

Company/Institute

Ecole centrale de Lyon

Country

France

City

Ecully

Geofield

Where to apply

Website

https://www.abg.asso.fr/fr/candidatOffres/show/id_offre/120996

STATUS: EXPIRED