Structures - Sizing

Objectives
The aim of this course is to acquire:

in-depth knowledge of aeronautical structural design and associated methods
methodological and analytical tools for producing a part justification file to determine the critical loads the structure can support. High-cycle fatigue behavior of materials, linear fracture mechanics (stress and energy approach), localized plasticity (fracture mechanics, low-cycle fatigue and Neuber approach), cycle counting method and cumulative damage law.

Skills acquired

Be able to dimension an aerostructure architecture associated with a failure scenario using a "Fail Safe", "Safe live" or "damage tolerant" approach
Be able to determine the limit loads of thin, slender parts loaded in compression and potentially subject to instability
Be able to evaluate post-bifurcation behavior, dimensioning rules for aerostructure


Skills acquired at independent mastery level

Mobilize a broad field of fundamental and technical sciences related to aeronautical and space mechanical systems, and have the associated capacity for analysis and synthesis
Design and dimension mechanical systems
Choose and implement the relevant analysis and characterization methods for mechanical systems
Communicate and work as part of a team Manage and lead a work unit or a project group
Integrate into a professional environment in France or abroad Communicate orally and in writing in English


Skills acquired at the supervised master's level

Design, dimension, implement and test a metallic or composite repair/modification
Have a global systemic approach to mechanical systems Reason in a context of international regulatory constraints
Anticipate, decide in a situation of uncertainty Be results-oriented (costs, deadlines, quality) and customer-oriented
Evaluate one's own skills and steer one's career path


Skills acquired - Level : In progress
Integrate financial, legal and contractual aspects into engineering practice

Contents
Damage tolerance:

Introduction, historical damage tolerance
Linear fracture mechanics Kt vs K stress approach
Linear fracture mechanics energy approach
High cycle number fatigue (S/N curve, effect of average stress)
Cycle counting method, Rainflow, cumulative damage law
Localized plasticity, low cycle fatigue, Neuber method
Crack propagation in fatigue
Case study, Franc2D, Afgrow, ...

Buckling, instability :

Notion of buckling and instability, equilibrium of elastic systems
Case of Euler buckling, influence of boundary conditions
Effect of plasticity
Buckling of stiffened panels
Notion of structural stability subject to conservation forces, energy criteria, bifurcation, post-bifurcation behavior
Case of systems with several ddl
Case of following forces Beck's beam, aerodynamic flutter

Pedagogical acquisition method
Integrated lectures / TDs

Specialization: Aeronautical structures