Calvin D. Rans

Biography

Research Interests

My core research interest is in developing a mechanistic understanding of the failure and degradation of lightweight aircraft materials and structures. True structural optimization that aims at minimizing weight without sacrificing safety can only be achieved by a thorough understanding of failure and failure progression. With such knowledge, structures can be designed to fail in a slow, progressive, and obvious manner, enabling failures to be detected and repaired long before they become critical to the safety of the aircraft. This design philosophy is known as Damage Tolerant Design.

Material selection plays a large role in determining the damage tolerance of an aircraft structure. There is, however, no single material that provides every answer. Currently there has been a recent trend to move more towards all composite aircraft (Boeing 787 and Airbus A350) to attempt to address some of the shortcomings of aerospace metallic alloys used in older aircraft. This “switch” from metal to composite has not been as smooth as hoped due to the fact that composite materials have their own unique set of shortcomings as well. It is my belief that both material classes, and hybrid variants of them (including Fibre Metal Laminates) all have a role to play in aircraft structures. My research thus does not focus on one single material class, but seeks to understand failure progression and structural shortcomings in metals, composites, and hybrids to allow the optimal use and selection of these materials in future aircraft structures.

Summary of Research Projects

• Damage tolerance prediction of bonded and integrally stiffened panels;
• Selective application of composites and hybrid materials to improve the damage tolerance of traditional metallic aircraft structures;
• Novel internally stiffened Fibre Metal Laminate (FML) concept for narrow body aircraft fuselage shells;
• Delamination growth in bonded metallic and composite structures;
• Development of a damage tolerant bonded patch repair;