ABSTRACT
Review of various aspects of basic fracture mechanics in Chapters 2 and 3 was
supported by a number of numerical examples in order to indicate briefly how
the formulas featuring the particular stress intensity values and externally applied
nominal stresses can be used in design. It became clear, as expected, that linear
elastic fracture mechanics (LEFM) shows limited concern with forces and stres-
ses because, as experience has shown in a number of well-documented cases,
conventional stress analysis and design failed either to predict or explain cata-
strophic failures. This is the historical basis on which modern fracture mechanics
has grown and prospered. All structures under load contain varied amounts of
strain energy available for propagating the ever present cracks and flaws. It is
simply a self-destructive process on a “micro” and “macro” level if we say
that “microcracks” are those that are beyond our capability to detect.
