The objective of this course is to explore certain aspects of solid mechanics from both theoretical and experimental perspectives, focusing on techniques that incorporate information related to discontinuous point of view. In the classical approach to studying solid mechanics problems, the assumption of continuity and the tendency to regularize information are commonly employed. This strategy is effective for solving many practical situations. However, in the present course, we emphasize methods that aim to extract information about perturbations or discontinuities that occur in the response of structures. Certain aspects of solid mechanics, such as Fracture Mechanics and Elastodynamics, will be revisited. Additionally, specific techniques like Acoustic Emission analysis will be considered, with focus on interpreting Acoustic Emission signals. Theoretical approaches particularly suited to address the aspects highlighted in this course will be introduced, such as the Fiber Bundle Model and numerical versions of the Discrete Element Model. Finally, examples will be provided to demonstrate the usefulness of adopting this perspective.

PhD students in this course should know solid mechanics well, have some experience with theoretical and experimental methods, and understand Fracture Mechanics and Elastodynamics. Familiarity with numerical modeling, and basic skills in interpreting signals from Acoustic Emission analysis will also help

Guest Lecture: Ignacio Iturrioz He has graduation (1988) in Civil Engineering for the National North East University UNNE, Resistencia- Argentina. He obtains his Master's Degree (1991) and his Doctoral Degree (1995) in the Post-Graduation Program in Civil Engineering at the Federal University of Rio Grande do Sul ( CPGEC/ UFRGS). Since 2000 is an Ordinary Professor in the Mechanical Department of the Federal University of Rio Grande do Sul. (DEMC/UFRGS) and act as a permanent professor in the Postgraduate Program in Mechanical Engineering PROMEC/UFRGS. He stay as visiting professor in the Polito –Italy, (2011) and two stages in The Universita Degli Studi di Parma Italy (2017, 2019). He has experience in Micromechanics, Fracture mechanics, Vibration structures, and Projects in Steel Structures. Simulation with a version of Discrete Element Methods. He has a research productivity Grant PQ1_C by CNPQ. 1- (3hs) Introduction. Theoretical Background I: Fracture Mechanics. Key concepts include the definition of fracture mechanics parameters, such as the linear parameters G (energy release rate) and K (stress intensity factor), as well as non-linear parameters like COD (Crack Opening Displacement) and the J-Integral. Additionally, the critical distance approach proposed by Taylor and other bi-parametric methodologies will be discussed. The concept of size effect and the fragility number will also be introduced, offering insights into the behavior of materials under fracture conditions. 2- (3hs) Theoretical Background II: Elastodynamics Applied to Solids The application of elastodynamics to solids, focusing on the characteristic wave velocities and the definition of reflection and refraction laws. It examines the interaction of waves with both external geometries and internal microstructures. Key topics include Lamb waves, dispersion curves, and phonon structures. Additionally, the potential to alter static or dynamic "material properties" by modifying the microstructure, as seen in metamaterials, will be discussed. This highlights the innovative possibilities of tailoring material behaviour through microstructural design. 3- (3hs) Methodologies: In the present modules is explored two Key approaches: Acoustic Emission Technique: The focus is on interpreting acoustic emission data as indicators of failure precursors, particularly in the context of continuous phase transitions and crackling-type problems. The theoretical basis of the Discrete Element Strategies: (i) Simple Models: Bundle Model, the Stick-slip Model, The Fuse Model. (ii) The Lattice Discrete Element Method and Peridynamics. 4- (3hs) Examples of Applications, where the ideas and technics applied are combined to solve Engineering Problems. The examples will be defined taking into account the student profiles. 5- (7hs) Evaluation Activity: Practical tasks, Exam, meeting extra class, answer questions.

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P.D.2-2 - Luglio