Hello, I welcome you in the course The Art of Structures II which is offered by EPFL in Lausanne, Switzerland. This course is based on the book: The Art of Structures by the professor Aurelio Muttoni. As its name implies, this course is the second part and it is preceded by the course : The Art of Structures I Along this lecture, I am going to give you some ideas about what we mean by a structure, I will show you the path of structures which is the program that we follow for this course, I will precise the content of the course The Art of Structures II and the course's supports which which will be available to you. I will insist on the necessary prerequisites, as well as the material that you must have to be able to properly follow this course and successfully solve the exercises. Finally, I will give you some indications about the way this course will be graded, so that you can get a certificate at the end of the course. The path of structures that you can see here is really the table of contents of the book <i>The Art of Structures</i>. It stretches from the left to the right over ten chapters. The part which is on the left, here, deals with the material of the course : The Art of Structures I, while the part which is on the right, deals with the material of the course : The Art of Structures II. This is the one I am introducing to you now. The course The Art of Structures I is a mandatory prerequisite to be able to follow the course The Art of Structures II. In this course, we are studying equilibrium, we understand how structures work, what loads act on them, what internal forces are induced within the structures by applied loads. We learn how to analyse their behavior, but also how to design new structures. The first course also includes an introduction to know how to dimension, that is to say to choose the dimensions according to the material the structure will be built with. The course The Art of Structures I looks at cables structures, such as the one we can see here in this roof, and also here in the Golden Gate bridge ; it looks at membrane structures, such as this public place cover, in which there are elements in tension ; it looks at arch-shaped structures, such as these arches of the "Pont du Gard", or this arch bridge by the Swiss engineer Robert Maillard. There is a type of structures which is not represented here which is called an arch-cable that we also introduce in the first course. The arch-cable is simply the combination of an arch and a cable within a structure. You have here the content of the course The Art of Structures II. We will start to deal with truss structures, then we will study beam structures, and finally frame structures. In every lecture, we will first study the aspect of two-dimensional structures, then we will study the aspect of three-dimensional structures. It will enable us to introduce some types of derived structures or else, a bit more important, as the one of slabs within the framework of the lecture dealing with beams. Finally, the last lecture will be devoted to the stability of elements in compression which is not a type of structures, but which is an important phenomenon to design and dimension structural elements subjected to compression. This is a repetition, but The Art of Structures I is the foundation of the tower that we are building here. If you do not have the proper basics from this course, it is unlikely that you can build in a stable manner the course The Art of Structures II. So, one more time, I encourage you, if your notions are uncertain or if you did not follow it yet, to follow the course The Art of Structures I. The course The Art of Structures II has numerous course supports. The first one is the one you are watching now : the videos which are available on-line. These videos go along with PDF supports which I strongly recommend you to print and to have with you when you follow the videos. These supports are not complete and require that you add yourself the graphical constructions, as well as the remarks, that I make myself in the videos. It will enable you to have reliable notes to, thereafter, work on the exercises. The exercises will take place on the website i-structures which is an e-learning website that exists since several years, on which you will also find informations in HTML about the diverse subjects of this course. Finally, but I have already mentioned it in the introduction, you will also be able to call on the book The Art of Structures by the professor Muttoni, which exists in French, in English and in Italian. It is not absolutely mandatory to use it, but I encourage you to purchase it or to borrow it for the duration of the course. The necessary material, in addition to a computer -- since you are already using one, I think you have access to it -- will be drawing material, so some paper or a notebook, pencils and blue and red colored pencils, as well as a rubber and a calculator. About computers, I have to say that most of the tablets or mobile phones that we can find nowadays cannot execute the Java applets which are frequently used within the framework of the exercises. So, for this part of the exercises, you will need to have access to a computer which can execute Java applications, that means a desktop computer or a laptop. Most of the time, it is possible. As already mentioned, you will also have to print the course supports, even though it is also thinkable to use the annotation function for PDF files. Finally, I am going to give you some informations about the exercises and the grading. The exercises, for which you will have a link from Coursera, will take place on the i-structures website of EPFL. You will just need to insert your Coursera login and password and you will reach it automatically. Please respect the time limits to do the exercises. Generally, they must be done within a one-week period. Each completed exercise will be corrected and graded between 0 and 100. The conditions for success, that is to say the average grade for all the exersises of the course, are indicated on Coursera. For those who will obtain the best results, they will have the possibility, if their average grade reaches a certain level, to get a certificate with a distinction. I thank you for your attention, I wish you a happy discovery of this course : The Art of Structures II, and I encourage you to start as soon as possible to study the lectures which are related to truss structures.