Chapter 1 - Introduction

Abstract

This chapter introduces the repair process. Bonded repair of metallic aircraft structure is used to extend the life of flawed or under-designed components at reasonable cost. Such repairs generally have one of three objectives: fatigue enhancement, crack patching, or corrosion repair. To extend the life of these aircraft, repairs have been made to arrest these cracks. Composite doublers or repair patches provide an innovative repair technique that can enhance the way aircrafts are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, a single composite doubler is bonded to the damaged structure. Adhesively bonded composite repairs have many advantages over mechanically fastened repairs, such as no new stress concentration created by new rivet holes; high stiffness-to-weight and strength-to-weight ratios of the patch, thus reducing drag; patches are readily formed into complex shapes, permitting the repair of irregular components; high fatigue and corrosion resistance of the composite; and potential time savings in installation. This repair technique has been used in the area of military aviation. This chapter reviews the past and current work on the design and analysis of bonded repairs.