The course aims to provide students with the basic knowledge required to properly identify and solve the structural problems related to the design of machines. There is particular focus on the elastic behaviour of materials and to the definition of the parameters describing the applied stresses and the strength of materials.
F.P. Beer , E. Russell Johnston Jr. , J.T. Dewolf , D. Mazurek
Mechanics of Materials
McGraw-Hill
Learning Objectives
The course gives students the knowledge necessary to perform both design and structural validation of simple mechanical components subjected to static stress.
It also provides knowledge of the basic concepts of the theory of elasticity (stress, principal stress, strain, Hook's law).
The theoretical topics dealt with in the course are supported by numerous applied examples, in order to acquire the operative tools and to show the link between analytical models and real structures.
At the end of the course, students will have acquired the basic knowledge of the mechanics of deformable elastic bodies, with particular reference to the technical theory of beams.
Students will be expected to have acquired a general knowledge of the mechanical properties of materials.
Students will be able to perform both design and safety assessment of some simple structural elements subjected to different load configurations, with particular reference to the components of machines. In particular students will acquire the ability to size and to verify the functionality of mechanical systems.
Students will have the tools to critically evaluate structural problems and to choose the most suitable method in order to apply the theoretical knowledge to actual cases concerning the solution of elastic beams.
Students will acquire the ability to communicate and express problems concerning the subjects of the course. They will be able to use the appropriate technical terminology to expose the disciplinary themes concerning structural mechanics in a clear and rigorous way.
Prerequisites
Differentiation and integration of the elementary functions,
vector analysis, concept of force and moment of a force, equations of static equilibrium.
Teaching Methods
Lectures and exercises in classroom.
As a rule, lectures will follow as much as possible the recommended text, so that the student can critically review what has been explained in the classroom.
The applied aspect is highlighted by the introduction of a significant number of examples and exercises solved in the classroom.
Further information
It is optional but strongly recommended to attend the course
Type of Assessment
The exam is based on an individual oral test.
In the test, the student will be asked to solve some exercises of the same type as those carried out in the classroom during the lessons. Moreover, the student must explain and justify the application of the particular techniques and methodologies selected to obtain the desired results.
The test aims to verify:
- the ability to understand the problems proposed
- the ability to correctly apply theoretical knowledge
- the ability to choose, appropriate and effective methods of solution among the possible alternatives
- the ability to perform both design and safety assessment of some simple components of machines.
Course program
Constraints and degrees of freedom of a system. Static equilibrium. Centroid, moments of inertia. Definition of strain and stress.
Rigid bodies: support types, statically determinate and indeterminate structures, determination of constraint reactions.
Evaluation of internal forces, normal stress, shear, bending, torque. Diagrams of characteristics of internal forces for two dimensional problems. Evaluation of the stress and strain state in some mechanical components.
Fundamentals of mechanical properties of materials. Elastic behaviour, Mohr circle, Hook,s law. Materials used for mechanical components and their properties: static test, plastic strain, hardening, fatigue and Wöhler's curves, fragile and ductile fracture, hardness, resilience, toughness, unified tests to evaluate mechanical properties.
Failure criteria, geometric stress concentration factor, safety factor, analysis and design calculation of beam structures. Sizing of simple components commonly used in machines.