LEARNING OUTCOMES

The students attending this course gain a fundamental understanding of Structural Integrity and the Damage Tolerance-based design of metallic and composite structures. They will acquire knowledge of damage initiation, propagation and fracture mechanisms as well as the concept of stress intensity factors and their experimental determination. The course will also solidify their understanding of the principles of residual strength and critical failure load in metallic and composite materials and explore the behavior of damaged structures under complex loading conditions. Furthermore, they will investigate fatigue fracture in metallic and composite materials through life prediction models and learn to apply the damage tolerance design methodology. Finally, they will be introduced to numerical simulation methods for analyzing damage propagation in metallic and composite materials from a structural integrity standpoint.

The learning outcomes of this course correspond to the descriptive indicator 8, according to the European Qualifications Framework.

COURSE CONTENT

Introduction to damage concepts and failure mechanisms in metallic and composite materials. The concept of residual strength for metallic and composite materials. Linear fracture mechanics theories, stress intensity factor analytical and numerical approaches for its determination. Experimental techniques for determining the critical stress intensity factor. Non-linear fracture mechanics, J-Integral concept and the crack tip opening displacement as failure criteria.

Basic principles of fail-safe, safe-life and damage tolerance design methods, the role of Non-Destructive Inspection methods.

Failure criteria in metallic materials. Crack propagation criteria, fatigue fracture and fatigue life prediction models for structural components, crack retardation models. The philosophy of Damage Tolerance-based design in composite materials, failure modes and criteria, fiber/matrix failure, delamination, Barely Visible Impact Damage (BVID), properties degradation. Simulation of damage propagation and residual strength calculation for metallic and composite structures using the Finite Element Method. Example and application of the damage tolerance design approach.