The aim of the course is the introduction of the fundamental concepts of design, sizing, assessment of strength and life evaluation of aeronautical components. The study will start with a general description of the most used mechanical components for aeronautical applications (shafts, bearings, gears, frames, etc.) and of the methods of jointing (rivets, welding), with the definition of principles and methodologies for its detailed design. After this first introduction, will be considered the different design methods applied for the aeronautical structural elements (Safe Life, Fail Safe, Damage Tolerant and Flaw Tolerant).

In addition, the knowledge related to the mechanical behaviour of materials, with particular attention to the fatigue behaviour, will be analysed and the different methods to take it into account will be explained (high cycle fatigue, variable amplitude loading fatigue, damage calculation, nucleation and propagation of cracks, presence of defects); after this, the main formulation for the structural integrity assessment will be shown (static and fatigue assessment, multiaxial state of stress, etc.).

Several applications of the previously defined concepts will be carried out, with also experimental application.

The students will develop the knowledge of the main tools used for the design and assessment of the most important machine components involved in aeronautical platforms subjected to static and fatigue loading. Thanks to the practices that are focussed on case studies, the students will improve the skills necessary for practical design application. The case studies include activities of laboratory tests and of Finite Element Method application, thus providing the capability to approach the solution of a problem with different tools (analytical, numerical and experimental), to understand their assumptions and limitations, and to analyse and critically discuss the results. The final reports that the students are asked to write will improve the capability on writing a technical design report.

Main topics are:

- functional description of the most common machine elements with aeronautical application (shafts, bearings, gears, frames, riveted and welded joints);

- fatigue design methodologies (Safe Life, Fail Safe, Damage Tolerant and Flaw Tolerant);

- mechanical behaviour of materials (static and fatigue behaviour, variable amplitude loadings, nucleation and propagation of cracks, defects);

- structural integrity assessment (static and fatigue assessment, multiaxial state of stress);

- application on mechanical and aeronautical components.

Course organization

Lessons and practices: lessons and practices, integrated together, will be developed during the course.

Experimental labs: during the course, some experimental lab experiences on aeronautical components and systems will be carried out. A report on the labs experiences is requested and is compulsory.

The courses assumes that the students already possess the basic knowledge of Mechanics of Structures and Basic Machine Design, including kinematic analysis and solutions of beams, De Saint-Venant cases, 3D stress and strains analysis, main failure theories and assessment under static loading for brittle and ductile materials.

The exam is based on a compulsory written test followed by a facultative oral one. Both of them cover all the topics of the course. The written test will include the solution of numerical exercises, aimed at assessing the capability of application of the design tools to practical  cases and questions aimed at assessing the knowledge of the theoretical topics included in the program. The oral test will prove the capability of critically discuss the design tools and their limits and or applicability conditions. In addition, the design report on the experimental/numerical activities performed on an aeronautical component will be considered for the final mark of the exam.