PORTALE DELLA DIDATTICA

### Fundamentals of strength of materials

01NLAJM, 01NLALI

A.A. 2018/19

Course Language

Inglese

Course degree

1st degree and Bachelor-level of the Bologna process in Ingegneria Meccanica (Mechanical Engineering) - Torino
1st degree and Bachelor-level of the Bologna process in Ingegneria Dell'Autoveicolo (Automotive Engineering) - Torino

Course structure
Teaching Hours
Lezioni 53
Esercitazioni in aula 27
Teachers
Teacher Status SSD h.Les h.Ex h.Lab h.Tut Years teaching
Paolino Davide Salvatore   Professore Ordinario ING-IND/14 53 0 0 0 5
Teaching assistant
Context
SSD CFU Activities Area context
ING-IND/14 8 B - Caratterizzanti Ingegneria meccanica
2018/19
At the end of this course it is required that student easily handle some typical tools of analytical methods for the static behavior prediction at least of beamlike structures. Fundamental goals of the discipline are: •a comprehensive knowledge, understanding and distinguishing of mechanical properties and strength of ductile and brittle materials; linear and nonlinear elastic behaviour conditions; concepts of stress, strain, displacement and rotation, described in both principal and non principal reference frames; static failure criteria and safety factor; geometrical properties of plane figures, interpreted as cross section of beams; theory of beam and relations between stress and load for each static behavior foreseen by De St Venant. In addition, student will get acquainted with the performing of fatigue verification of structures subjected to time-varying uniaxial loading conditions. •providing some skills as the basic tools to: 1) simplify to a level of elementary scheme the layout of a beamlike mechanical component and perform a complete static analysis; 2) evaluate the degree of indeterminacy of the system; 3) calculate reaction forces of statically determinate structures; 4) calculate the internal stress resultant diagrams, stresses, strains, displacements and rotations of each cross section of one-dimensional elements; 5) identify the critical points of the structure and compute the equivalent stress to be compared to the strength of material or even to buckling threshold; 6) verify structures subject to uniaxial fatigue.
At the end of this course it is required that student easily handle some typical tools of analytical methods for the static behavior prediction at least of beamlike structures. Fundamental goals of the discipline are: •a comprehensive knowledge, understanding and distinguishing of mechanical properties and strength of ductile and brittle materials; linear and nonlinear elastic behaviour conditions; concepts of stress, strain, displacement and rotation, described in both principal and non principal reference frames; static failure criteria and safety factor; geometrical properties of plane figures, interpreted as cross section of beams; theory of beam and relations between stress and load for each static behavior foreseen by De St Venant. In addition, student will get acquainted with the performing of fatigue verification of structures subjected to time-varying uniaxial loading conditions. •providing some skills as the basic tools to: 1) simplify to a level of elementary scheme the layout of a beamlike mechanical component and perform a complete static analysis; 2) evaluate the degree of indeterminacy of the system; 3) calculate reaction forces of statically determinate structures; 4) calculate the internal stress resultant diagrams, stresses, strains, displacements and rotations of each cross section of one-dimensional elements; 5) identify the critical points of the structure and compute the equivalent stress to be compared to the strength of material or even to buckling threshold; 6) verify structures subject to uniaxial fatigue.
Some typical mathematical tools (study of functions, computation of derivatives and integrals, matrix algebra, solution of eigenvalue/eigenvectors problems) and physics (basic concepts of kinematics and statics) and some basics of materials sciences (materials classes and properties).
Some typical mathematical tools (study of functions, computation of derivatives and integrals, matrix algebra, solution of eigenvalue/eigenvectors problems) and physics (basic concepts of kinematics and statics) and some basics of materials sciences (materials classes and properties).
Topics dealt within this course are herein listed. 1. Statics : Basic concepts of static behavior of structures (force, moment, rigid and deformable bodies), loading conditions, constraints, static and kinematic determinacy, equilibrium conditions and equations. Computations of reactions, internal forces, diagrams. Beams, bars, trusses. Outlines of Virtual Work Principle and application to undetermined structures. 2. Stress : Stress vector, tensor, components. Principal stresses and direction, related computation. Mohr circles. Equivalent stress definition and computation. 3. Strain : Rigid body motion and strain definition in elastic body. Strain components, principal strain and direction. Stress-strain relations, Hooke’s law. Elastic properties of materials. Elastic energy storage. 4. Strength of materials : Tensile test, material behaviour and properties. Elastic coefficients. Yielding phenomenon, brittle and ductile materials. Safety factors in statics. 5. Beam theory : De Saint Venant principle, beam definition, loading conditions, axial, flexural, shear, torsional behaviors. Approximated solutions for torsion of rectangular cross sections, multiple rectangles and thin walled structures. Computation of stresses, strains, displacements and rotations. Shear centre. Coupled behavior. Buckling and elastic instability. 6. Uniaxial mechanical fatigue at high number of cycles (HCF) : fundamental parameters, SN diagram, effect of the mean stress (Haigh, Goodman-Smith, Ros and Master diagrams). From material to component: surface finishing effect, load type effect, dimension effect and notch effect. Component life and fatigue safety factor. Fatigue with varying amplitude stress (Palmgren-Miner cumulative damage rule).
Topics dealt within this course are herein listed. 1. Statics : Basic concepts of static behavior of structures (force, moment, rigid and deformable bodies), loading conditions, constraints, static and kinematic determinacy, equilibrium conditions and equations. Computations of reactions, internal forces, diagrams. Beams, bars, trusses. Outlines of Virtual Work Principle and application to undetermined structures. 2. Stress : Stress vector, tensor, components. Principal stresses and direction, related computation. Mohr circles. Equivalent stress definition and computation. 3. Strain : Rigid body motion and strain definition in elastic body. Strain components, principal strain and direction. Stress-strain relations, Hooke’s law. Elastic properties of materials. Elastic energy storage. 4. Strength of materials : Tensile test, material behaviour and properties. Elastic coefficients. Yielding phenomenon, brittle and ductile materials. Safety factors in statics. 5. Beam theory : De Saint Venant principle, beam definition, loading conditions, axial, flexural, shear, torsional behaviors. Approximated solutions for torsion of rectangular cross sections, multiple rectangles and thin walled structures. Computation of stresses, strains, displacements and rotations. Shear centre. Coupled behavior. Buckling and elastic instability. 6. Uniaxial mechanical fatigue at high number of cycles (HCF) : fundamental parameters, SN diagram, effect of the mean stress (Haigh, Goodman-Smith, Ros and Master diagrams). From material to component: surface finishing effect, load type effect, dimension effect and notch effect. Component life and fatigue safety factor. Fatigue with varying amplitude stress (Palmgren-Miner cumulative damage rule).
This course is organized in two parts. Lectures will give a straight presentation of relevant topics to be studied to perform a complete structural static analysis of some mechanical structures. Practice hours will be offered to solve examples, numerical exercises and practical cases and even an exam simulation.
This course is organized in two parts. Lectures will give a straight presentation of relevant topics to be studied to perform a complete structural static analysis of some mechanical structures. Practice hours will be offered to solve examples, numerical exercises and practical cases and even an exam simulation.
Textbooks: Some notes directly taken from the classes will be shared with students through the website. Theoretical aspects presented during the lectures can be found on the following textbooks: 1.D.Gross, W.Hauger, J.Schroder, W.A.Wall, N. Rajapakse - "Engineering Mechanics 1: Statics", Springer. 2.V. Da Silva - "Mechanics and strength of materials", Springer. 3.J.D. Renton, "Applied elasticity : matrix and tensor analysis of elastic continua", Chichester, Horwood, New York: Wiley, 1987 4.J.A. Bannantine, J.J. Comer, J.L. Handrock, “Fundamentals of metal fatigue analysis”, Prentice Hall, Englewood Cliffs, 1990. or evenly, but the textbook is just partially dedicated to the above topics: 1.J. Beer, S.Johnston - "Solid mechanics", McGraw-Hill.
Textbooks: Some notes directly taken from the classes will be shared with students through the website. Theoretical aspects presented during the lectures can be found on the following textbooks: 1.D.Gross, W.Hauger, J.Schroder, W.A.Wall, N. Rajapakse - "Engineering Mechanics 1: Statics", Springer. 2.V. Da Silva - "Mechanics and strength of materials", Springer. 3.J.D. Renton, "Applied elasticity : matrix and tensor analysis of elastic continua", Chichester, Horwood, New York: Wiley, 1987 4.J.A. Bannantine, J.J. Comer, J.L. Handrock, “Fundamentals of metal fatigue analysis”, Prentice Hall, Englewood Cliffs, 1990. or evenly, but the textbook is just partially dedicated to the above topics: 1.J. Beer, S.Johnston - "Solid mechanics", McGraw-Hill.
Modalità di esame: Prova scritta (in aula);
Exam: Written test;
Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.
Exam: Written test;
The final exam consists of two written tests, taken in two different dates. ----- The 1st test is an open-book test and it consists of 3 (three) exercises to be numerically solved. The test lasts 2 hours. The difficulty level of the exercises is comparable to those solved during the tutorials of the course. Exercise #1 focuses on the calculation of reactions and internal actions of either a beam assembly or a truss. Exercise #2 focuses either on the stress field in beams sections or on stress-strain relationships and Mohr circles. Static verification at the maximum stressed points might be asked. Exercise #3 focuses on fatigue verification of structures subjected to time-varying uniaxial loading conditions. To take the exam, the student has to show a valid identity document with a clear picture. In absence of this evidence, the candidate will not be allowed to take the exam. Any student found with any communication device (phones, tablets, laptops, ect…) switched on during the test will be expelled out of the room and his/her test will be invalidated. The maximum score is 30/30. The minimum score to access the 2nd test is 18/30. ----- The 2nd test is a closed-book exam and it consists of 3 questions about the contents of the course, requiring a written demonstration, response, calculation or a graphical solution. Students who attended DexPiLab during the course, will only have to answer to 2 questions. The test will last 45 minutes. Any student caught cheating during the exam (i.e. copying solutions from notes or from other candidates) will be expelled out of the room and his/her exam will be invalidated. ---- The 2 tests must be taken in the same exam session, strictly and only on the official dates published through the website of Politecnico di Torino. For the student to pass the exam, both tests must be evaluated sufficient (minimum score of 18/30). Even if the student only fails the 2nd test the whole exam (1st and 2nd test) shall be completely repeated. The final mark will be a weighted average of the marks of the 2 tests (final mark = 2/3*A + 1/3*B, with A: mark of the 1st test; B: mark of the 2nd test).
In addition to the message sent by the online system, students with disabilities or Specific Learning Disorders (SLD) are invited to directly inform the professor in charge of the course about the special arrangements for the exam that have been agreed with the Special Needs Unit. The professor has to be informed at least one week before the beginning of the examination session in order to provide students with the most suitable arrangements for each specific type of exam.