This chapter deals broadly will the subject of impact resistance, which is the study of damage induced by foreign object impact in a laminate and the factors affecting it. Methods for predicting impact damage are discussed in Chapter 5, and the study of damage tolerance – that is, the effect of impact damage on the stiffness, strength, fatigue life, and other properties of the laminate – will be presented in Chapter 6.

An understanding of impact damage development, the failure modes involved, and the various factors affecting damage size has been gained through extensive experimental studies. In this chapter, several of the most commonly used impact test procedures will be discussed. Experimental techniques for impact damage detection and detailed mapping of the damage zone after impact are reviewed. Of the many different techniques discussed in the literature, some are nondestructive, and others are destructive. Some techniques are used extensively, and others have seen only limited applications. A few experimental techniques have been developed to observe damage development during the impact event. While not attempting to give an exhaustive description of the techniques used, the objectives are to briefly describe each one and to give a general idea of what the most commonly used techniques are.

Understanding the process of impact damage initiation and growth and identifying the governing parameters are important for the development of mathematical models for damage prediction, for designing impact resistant structures, and for developing improved material systems. The basic morphology of impact damage, its development, and the parameters affecting its initiation, growth, and final size will be described.