Corso di Laurea Magistrale in Chemical Engineering for Industrial Sustainability (LM-22)

Anno Accademico 2014 - 2015




Course teacher: Prof. Giovanni Grasso

Room # 32 – Dipartimento di Ingegneria Industriale  Building 3.

Tel 095-7382406, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Office hours: Day: : Friday 10.00-13.00


The aim of the course is to provide chemical engineers, although thet are not specialists of structural
calculation, the elements to understand the problems of this sector and interact with the designers of
the equipment. The course analyzes the main mechanisms of material failure - static overload,
viscous sliding, crack propagation, fatigue; it presents the method to calculate the fundamental
mechanical components, the connections (welded and bolted) and the pressure vessels.
Expected learning outcomes
The course aims to:
1) provide the knowledge to understand the mode of failure, under constant or cyclical load, of
structural components and connections present in plants;
2) illustrate the main methods of structural analysis used in the design of vessels subject to pressure
and their implementation in the legislation of the sector.
Prerequisites/Previous knowledge
The students will be required prior knowledge of:
1) the fundamental principles of statics (equilibrium, free body diagram),
2) kinematics (motion of rigid bodies),
3) fondamental states of stress (traction, bending, torsion).
- Recall and integration of state of stress and strain knowledge (6 hours).
- Subsidence under constant load. Ideal stress for brittle and ductile materials,
viscous sliding at high temperature, unstable crack propagation, safety coefficients (6 hours).
- Subsidence under cyclic load (fatigue). Nucleation and crack propagation,
diagrams for the presentation of the characteristics (Woehler, etc),
factors affecting resistance (10 hours).
- Threaded joints. Characteristics, materials, tightening stress, distribution of effort
among coils. Behavior under load, static strength and fatigue. Gasket tightening. (6 hours).
- Welded Joints. Types of joints, welding procedures and defects. Stress state in the head
joints and corner weldings, resistance calculations for static and fatigue strength (6 hours).
- Vessels and pipelines: constitutive elements. Membraneous behavior of axialsymmetric shells.
Hints about the instability of cylinders subject to external pressure and on flat bottoms.
Edge effects (cylindrical shell): compatibility of deformations, additional tensions.
Cylinders of high thickness: general theory, states of stress due to pressure and temperature,
constructive solutions for high pressure (force, autofrettage) (22 hours).
- Vessels: Italian regulatory framework, European Directive 97/23 PED on pressure equipment,
harmonized standard EN 13444 (6 hours).
Course organization
For each group of lessons' subjects, training will be done with exercises of technical calculation
and/or structural tests and/or structural design of a pressure device and/or production line.
(30 hours).
Texts required or recommended: readings, lecture notes, other teaching material
- "Resistance of materials and of connections", L. Goglio, Levrotto & Bella, Torino, 2nd ed. (2014).
- Handouts regarding vessels, creep, welded joints, NDA.
Criteria, rules and procedures for the final test
The examination consists in an oral test.
The oral test will be an interview about the theoretical aspects of the topics, in order to check the
understanding of the methods of calculation and the physical phenomena involved as well as
analysis of draws and calculations of the exercises done during the course.