Effects of Defects – Design Values and Statistical Considerations

This chapter presents methods that can be used to evaluate the effects of common defects analytically and experimentally. It includes references to some of the most significant studies in this area that may serve as guidance for further analysis or experimentation. During the processing of composite structures, it is not uncommon to encounter cure cycle anomalies. The chapter provides a list of some of the cure cycle anomalies that can be encountered during the curing of thermoset-based composites. Sandwich design values are extremely sensitive to the following properties and damage: core-facesheet bondline integrity, core splicing integrity, and impact damage. Screening tests using design of experiments (DOE) techniques can maximize the efficiency of testing and can be used to study sensitivity of the process to certain defects. DOE can be a powerful tool to determine the significance of a particular process or defect and how it may influence certain mechanical properties.