Kjell Simonsson 2 Aim The aim of this lecture is to give a short introduction to the course Vibrations and fatigue in mechanical structures, TMMI09, autumn 2011. More specifically a short overview of the course content will be given (see below) the course information will be presented the study of vibrations in one degree of freedom (1-d.o.f.) systems will be started Please see the course home page for the latter material http://www.solid.iei.liu.se/Education
Kjell Simonsson 3 Course content A body or structure subjected to repeated loadings can fail, even though the magnitude of the applied loading is far below any yield- or static failure limit - we refer to this phenomenon as fatigue. Generally, the higher the load amplitude is, the shorter the life will be (in terms of loading cycles). By obvious reasons fatigue failures may be both dangerous and expensive, and must therefore be avoided. An additional complicating factor is that fatigue failures often occur without any previous "warnings", and are therefore especially awkward. As a result, fatigue design has become an increasingly important task in the modern product design process. Thus, one major aim of the course is to provide some basic skills in classical fatigue design! However, since the local stresses often are raised by dynamic reasons, the first part of the course will be designated to basic vibration theory.