OVERVIEW

Modern engineering is characterized by the use of various classes of materials and the design of new, advanced materials, also thanks to recent progress in manufacturing technologies. To optimize the design of the components and to avoid catastrophic failures, a clear understanding of the mechanics of materials is necessary. This module aims to provide the essential elements for materials and component design, also starting from existing models in Nature.

AIMS AND CONTENT

LEARNING OUTCOMES

Modern engineering is characterized by the use of different classes of materials and the design of new advanced materials, leveraging recent fabrication techniques (e.g., additive manufacturing). 3D printing, or additive manufacturing (AM), is emerging as a unique tool to fabricate novel materials with additional properties (i.e., multifunctional) triggered by 3D structures, by the use of multi-material technologies, and by smart materials. Yet, a deep understanding of mechanics and materials design is required when dealing with this new class of materials. To optimize the design of mechanical components and avoid unexpected failures, a careful selection and a clear understanding of the mechanical behavior of materials is required. This course aims to provide the necessary elements for the design with different classes of materials and for the design of new materials, also starting from models existing in nature. Some classes of materials will be studied considering their peculiarities in terms of mechanical behavior, evaluation of life under complex stress conditions (e.g. multiaxial fatigue), or defects. Composite materials of natural origin (e.g., bone, wood), biomimetic materials (inspired by natural materials), metamaterials, and multifunctional materials (e.g., self-sensing materials, shape-morphing) will be studied, considering various potential applications, from the biomedical field (e.g., design of scaffolds and bio-inspired prostheses) to automotive/aerospace (composites with enhanced mechanical properties and smart composites), and soft robotics (self-sensing and self-actuating materials for robotic manipulators, grippers, etc.). This course will provide a comprehensive approach to advanced engineering materials design, in particular multifunctional materials, where multiple functions can be achieved via inherent 3D complex geometries that enable enhanced and anisotropic deformations, the multi-material approach, soft materials, and embedded sensors (e.g., through conductive materials). A special focus will be given to a sustainable design approach, leveraging numerical modeling, proper materials selection and optimal design. It is a project-based course with theoretical lectures and numerical laboratories (use of FE-software and materials design&selection software). This course contributes to the following SDGs (Sustainable Design Goals) according to the 2030 Agenda for Sustainable Development by the UN (https://sdgs.un.org/goals):

AIMS AND LEARNING OUTCOMES

The module aims to:

•       Provide, through theoretical bases and project-based learning, the knowledge of different classes of advanced structural materials as alternative to conventional ones

•       Provide basic elements for the choice of alternative structural materials based on the application

•       Provide design criteria for new materials based on the chosen application

•       Describe the typical material models with particular attention to damage

•       Show examples of numerical applications and their analytical models

•       Explore potential applications of advanced engineering materials:

• Soft robotics (movements triggered by the anisotropy of the materials or structures)
• Morphing structures or shape-matching structures for wearable devices (based on metamaterials and lattice structures)
• Micro-robots for movements and gripping actions (based on smart metamaterials, e.g. soft composites with ferromagnetic nanoparticles)
• Self-sensing lattices (e.g., braces for orthopedic applications)
• Self-sensing structures for in situ monitoring

PREREQUISITES

Fundamentals of mechanics and machine design

TEACHING METHODS

The module consists of theoretical lectures and numerical exercises, equally divided. The latter will be carried out in the laboratory.

Students who have valid certification of physical or learning disabilities on file with the University and who wish to discuss possible accommodations or other circumstances regarding lectures, coursework and exams, should speak both with Professor Federico Scarpa (federico.scarpa@unige.it), the Polytechnic School's disability liaison.

SYLLABUS/CONTENT

• Introduction to the module. Overview of the motivations for design and the selection of advanced materials as alternatives to conventional materials. Ashby material selection charts.
• Fracture Mechanics. Introduction, Griffith's Theory, stress intensity factor. Calculation of the shape factor. Strain state at the crack tip, plastic zone radius. Calculation of the plastic zone radius, validity of Linear Elastic Fracture Mechanics (LEFM). Fracture toughness, standardized experimental tests. Defect characterization. Design calculation and static verification. Fracture and yielding control plan.
• Crack Propagation. Paris’ law, Broek, Walker, Forman. Effect of mean stress. Retardation effect. Calculation of crack propagation under random loading.
• Fatigue. Fatigue issues. High-cycle fatigue, multiaxial fatigue. Cumulative damage. Fatigue behavior of different classes of materials.
• Mechanical Behavior of Advanced Materials
  • Composite Materials
  • Notes on Plastic Materials
  • Notes on Cellular Materials
  • Biomimetic Materials (Case studies: e.g., bone, wood, nacre)
  • Multifunctional Materials (Case studies: self-sensing, self-healing functionalities)
  • Implementation in FEM codes

RECOMMENDED READING/BIBLIOGRAPHY

• Lorna J. Gibson, Michael F. Ashby. Cellular Solids: Structure and Properties. Cambridge University Press, 1999
• N. E. Dowling, Mechanical Behavior of Materials, Editore: Prentice Hall, Anno edizione: 2013
• L. Vergani, Meccanica dei Materiali, Editore: McGraw-Hill, Anno edizione: 2001
• Fred Nilsson, Fracture mechanics — from theory to applications, KTH Hållfasthetslära (Solid Mechanics), ISBN 91-972860-3-6. 2001
• Zenkert, D., Introduction to Sandwich Structures, 1995 – Student Edition
• Buehler, M.J., Atomistic Modeling of Materials and Failure, Springer-Verlag US 2008

TEACHERS AND EXAM BOARD

LESSONS

LESSONS START

https://corsi.unige.it/en/corsi/9269

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

The exam will consist of a group project followed by an oral exam, which will cover the module topics and include a discussion of the project.

ASSESSMENT METHODS

The exam will assess competence in the design process of a new material or a new component. Clarity in the presentation of individual topics and the ability to apply concepts to real-world cases—such as those carried out in the laboratory and discussed during the exam—will be evaluated.

FURTHER INFORMATION

Module taught in English.