ABSTRACT
Failure of a structural element occurs when it cannot perform its intended function. Material fracture is the obvious type of failure but not the only one. Excessive de ection is also a type of failure if the performance or the aesthetic value of the structure are compromised. Even if the part does not collapse, partially damaged materials may be considered failed, for example if cracking aects the aesthetic value of the structural element. De ections are easier to predict than damage and fracture. Prediction of de ections are addressed in Chapters 10 to 13 and in examples throughout this book. The objective of this chapter is to describe strength design; that is, to develop tools to predict damage and fracture of composites and to use those tools to select materials, congurations, and dimensions that allow the structure to safely perform its function.
