


Politecnico di Torino  
Academic Year 2012/13  
09IHRMA Fundamentals of structural mechanics 

1st degree and Bachelorlevel of the Bologna process in Biomedical Engineering  Torino 





Subject fundamentals
The course aims to provide the fundamental basis to perform the design and verification of structural components and mechanical systems subject to static and fatigue loads.
Topics covered, after a resume of static equilibrium concepts, are:  evaluation of the elastic properties and the static strength of materials by tensile test and some notes on creep;  state of stress and state of strain in mechanical elements in linear elastic conditions; combined stress failure theories; static safety factors;  calculation of stresses in onedimensional structural elements subjected to loads in plane and space: geometric properties of areas, de St Venant solid, equilibrium and internal forces diagrams in statically determinate systems; extensional, flexural, torsional and shear behaviour; equation of the elastic curve; elastic instability;  definition and effect of notches: the stress concentration factor; static component verification;  high cycle fatigue strength in terms of uniaxial stress: cyclic stress, nucleation and propagation of cracks, diagrams for the presentation of fatigue tests results; application to the verification of mechanical components, the main factors reducing the fatigue strength. 
Expected learning outcomes
Knowledge and understanding of the mechanical properties and strength of materials
Knowledge of methods for describing the state of stress and the state of strain in linear elastic conditions Knowledge of static failure criteria and the concept of safety factor Knowledge of methods for assessing the state of strain, stress and displacements in onedimensional structural elements Understanding the phenomenon of fatigue; knowledge of diagrams that describe the high cycle fatigue behaviour of materials. Knowledge of methods of verification of components subject to constant amplitude cycling stresses. Ability to verify elements subject to known static stress. Ability to calculate reaction forces of statically determinate structures. Ability to calculate the internal forces diagrams in statically determinate elements subject to known applied loads. Ability to assess the stresses and strain in sections of onedimensional elements with and without notches , known the internal forces applied to the section. Ability to perform fatigue assessment of components subject to constant amplitude cycling stresses. 
Prerequisites / Assumed knowledge
Concepts of mathematics (study of functions and computation of derivatives and integrals, matrix algebra, eigenvalue / eigenvectors problems) and physics (basic concepts of kinematics and statics).

Contents
The course content will be distributed as follows:
 fundamentals of statics, fundamental constraints; Equilibrium equations (1 CFU ) ;  stress and strain state in monodimensional structural elements subjected to plane and spatial loading conditions (de St Venant theory): tension/compression, bending, shear, torsion (2 CFU);  mechanical properties of materials, failure criteria and safety coefficients (1 CFU);  deformed shape of bending beams and overconstrained problem solution (1 CFU;  stress and strain state (1 CFU);  linear buckling (0,5 CFU);  fundamentals of mechanical high cycle fatigue. Design of elements subjected to fatigue load cycling (1,5 CFU). 
Delivery modes
The course is subdivided in:
 theory lessons (50 hours),  practical classes on the subjects presented at the theory classes (30 hours). 
Texts, readings, handouts and other learning resources
Suggested textbooks:
 Soma’ A. Fondamenti di meccanica strutturale Other suggested books: R.C. Juvinall, K.M. Marshek, Fondamenti della progettazione dei componenti delle macchine, Edizioni ETS J. A. Collins, Failure of materials in mechanical design, J. Wiley. 
Assessment and grading criteria
Written and oral exams have to be attended in order to pass the course.
The written exam consists of 23 exercises concerning the course subjects. Notes and textbooks cannot be used. The oral exam can be attended by students having reached a minimum score of 18/30 in the written exam through the solution of the selected parts of the exercises that will be indicated every time. The oral exam is optional for students who have obtained a score in the written exam between 18 and 24. The oral test is mandatory for students who have a score in the written exam a score higher or equal to 25/30 . The oral exam must be attended in the same exam session of the written exam in any of the official dates that will be communicated and published. The oral exam consists of a minimum of 2 questions on the content of the Whole course (answers must be satisfactorily and provided in a reasonable lapse of time). The absence of the student at the available date for the oral exam will be considered as the acceptance of the score obtained in the written exam if it is larger than the minimum required or the rejection of the score if it is not larger than the minimum required. 
