- March 16, 2017
- 3:30 p.m.
- 331 Randolph Hall
- Dr. Christopher M. Harvey; Loughborough University
- Faculty Host: Pradeep Raj
Material interfaces are often areas of weakness in material systems; hence, interface fracture toughness is always an important consideration when designing long-lasting material systems of either macroscopic or microscopic size. Unfortunately, however, interface fracture toughness is not purely an intrinsic material property which can be determined immediately from experiments. Instead it also depends on some other parameters such as loading conditions, interface properties and crack extension size. Different parameters produce different partitions of fracture modes I, II, and III, which determine the interface fracture toughness. It has been a major research topic over the past few decades to develop a general theory to determine the partitions. A powerful methodology has recently been discovered at Loughborough University to develop such a general theory. The theory has been used to predict: (1) the interface fracture toughness of macroscopic fiber-reinforced polymer specimens against delamination under both lateral loads and compressive post-buckling loads, (2) the spallation toughness of microscopic alumina films under compressive thermal residual stresses, (3) the adhesion energy of nanoscale graphene membranes, and (4) the telephone cord blister behavior exhibited by thermal barrier coatings undergoing spallation. In all cases, the theory explains and predicts experimental observations and test data very well. It is concluded that some important mechanics of interface fracture have been revealed.
Dr Christopher M. Harvey received his MEng degree in Aeronautical Engineering from Loughborough University in 2009, followed by his PhD from Loughborough University in 2012. Since 2012, he has been employed as Lecturer in Structural Mechanics at Loughborough University in the Department of Aeronautical and Automotive Engineering, where he is currently Programme Director of Aeronautical Engineering Undergraduate Courses. At present, his major research interests include the analytical, numerical and experimental aspects of interface fracture; the spallation mechanics of thermal barrier coatings and ultrasonically assisted drilling.