This book discusses the applications of fracture mechanics in the design and maintenance of asphalt concrete overlays. It provides useful information to help readers understand the effects of different material and loading type parameters on the fracture properties of asphalt concretes. It also reviews relevant numerical and experimental studies, and describes in detail design parameters such as aggregate type, air void, loading mode, and additives, based on the authors experience and that of other researchers.

Understanding fracture resistance of asphalt concrete is of great importance in designing pavements with long service life. This thesis focused on studying the micro and global fracture behavior of heterogeneous asphalt concrete with a numerical analysis approach. Finite element (FE) models were built with the capacity of taking heterogeneity into consideration. The asphalt concrete was modeled as a multi-phase material with coarse aggregates and fine aggregate matrix (FAM). Viscoelastic properties were assigned to the FAM. Different damage models were incorporated to study fracture at two length scales: micro-fracture within FAM and coarse aggregate-FAM interface under small displacement and global fracture resistance in the semi-circular bending (SCB) test. For micro-fracture simulation, asphalt mixture was modeled with both adhesive and cohesive failure potential. Two different fracture models, cohesive zone model (CZM) and extended finite element model (XFEM), were adopted to simulate fracture damage within the FAM (cohesive failure) and at the FAM-aggregate interface (adhesive failure), respectively. For global fracture properties, the SCB test was simulated to predict the crack propagation pattern and the load-crack mouth opening displacement (CMOD) curve of asphalt concrete. Parametric studies with different material properties of FAM and coarse aggregates-FAM interface, morphological characteristics of coarse aggregates, and testing conditions (loading rate and temperature) were carried out to study their effects on fracture behavior of asphalt concrete. The numerical models provide an effective method to study fracture mechanism of heterogeneous asphalt concrete and generates meaningful findings. The development of cracking shows that the damage in the FAM material would initiate first at a small displacement and then interconnect with the damage developed at the FAM-aggregate interface. The higher angularity and larger aggregate size induces the greater damage level; while the orientation angle along with aspect ratio has influence on the anisotropic behavior of asphalt concrete. On the other hand, the SCB test simulations show good agreements with experimental results in the literature. Increasing fracture strength and energy of FAM significantly improves fracture resistance of asphalt concrete. The spatial distribution and angularity of coarse aggregate affect crack path; while the gradation and size of coarse aggregate affect fracture strength of asphalt concrete.

Based on the Biot conference, named after Maurice Biot and held at Columbia University, this book contains over 170 original papers on different phases of poromechanics in many materials from soils and minerals to human bone. It covers testing and modeling.

This book is based on 40 years of research and teaching in the fields of fracture mechanics and plasticity. It will bring students and engineers from various disciplines up to date on key concepts that have become increasingly important in the design of safety-relevant engineering structures in general and in modern lightweight structures in the transportation industry in particular. Primarily intended for graduate students in the engineering sciences and practicing structural engineers, it employs a multidisciplinary approach that comprises theoretical concepts, numerical methods, and experimental techniques. In addition, it includes a wealth of analytical and numerical examples, used to illustrate the applications of the concepts discussed.

This book deals with the most recent numerical modeling of adhesive joints. Advances in damage mechanics and extended finite element method are described in the context of the Finite Element method with examples of application. The book also introduces the classical continuum mechanics and fracture mechanics approach and discusses the boundary element method and the finite difference method with indication of the cases they are most adapted to. At the moment there a no numerical technique that can solve any problem and the analyst needs to be aware of the limitations involved in each case.

The proliferation of technological capability, miniaturization, and demand for aerial intelligence is pushing unmanned aerial systems (UAS) into the realm of a multi-billion dollar industry. This book surveys the UAS landscape from history to future applications. It discusses commercial applications, integration into the national airspace system (NAS), System function, operational procedures, safety concerns, and a host of other relevant topics. The book is dynamic and well-illustrated with separate sections for terminology and web- based resources for further information.