Interfaces between two different mixes or strengths of concrete appear in large concrete structures involving mass concreting such as dams, nuclear containment vessels, cooling towers etc., since joints between successive lifts are inevitable. These joints and interfaces are potential sites for crack formation, leading to weakening of mechanical strength and subsequent failure. Research involvi...

Cohesive-zone models have been used to study the effects of strength and toughness on the delamination of beam-like geometries. The conditions under which linear-elastic interfacial mechanics provide a good frame-work for predicting failure of such systems have been studied. It has been determined that the phase angle derived from LEFM calculations provides an excellent description of the parti...

.............................................................................................................................. .i APPENDED PAPERS ............................................................................................................... ii PAPERS NOT INCLUDED IN THIS THESIS........................................................................ iii DIVISION OF WORK BETWEEN ...

Abstract Fatigue crack growth of austenitic and martensitic NiTi shape memory alloys was analyzed, with the purpose capturing effects distinct stress-induced transformation mechanics in two crystal structures. Mode I experiments were carried out, near-crack-tip displacements captured by in-situ digital image correlation (DIC). A special fitting procedure, based on William’s solution, used to es...

The Generalized/eXtended Finite Element Method (G/XFEM) has been established as an approach to provide optimally convergent solutions for classes of problems that are challenging the standard version (FEM). For with non-smooth solutions, those within Linear Elastic Fracture Mechanics (LEFM) context, FEM convergence rates often not optimal and bounded by strength singularity in analytical soluti...

This paper presents a new method for continuum based shape sensitivity analysis for a crack in a homogeneous , isotropic, and linear-elastic body subject to mixed-mode (modes I and II) loading conditions. The method is based on the material derivative concept of continuum mechanics, domain integral representation of an interaction integral, and direct differentiation. Unlike virtual crack exten...

Most of the existing concrete dams are subjected to cracking. These cracks are caused by various factors such as construction practices, curing, loads and volume change of mass concrete which reduce the efficiency, failure or instability of concrete dams. Using fracture mechanics as a new method to estimate stability and durability of concrete dams is recommended in scientific publications in w...

The concrete community in the United States has reached the point where it needs a standard test for measuring the fracture toughness of concrete. A concrete standard might be obtainable by adapting existing standards for cemented carbides and rock. These standards use the short rod specimen geometry and two associated test methods. The combination of specimen geometry and test methods may have...

This research investigates the stress mechanics of reinforced polyester composites when exposure to a sudden impact force, using experimental and analytical methods based on Linear Elastic Fracture Mechanics (LEFM) test procedures. In this study, distribution around crack tip zone for 14 samples with geometry 210 mm x 150 were investigated. KII intensity factors, critical stress, σC, shear τnt ...

The objectives of this work were to explore a methodology that combines static and dynamic finite element (FE) analysis, linear elastic fracture mechanics (LEFM) and experimental methods to investigate a worst-case scenario in which a previously damaged bone plate system is subjected to an impact load. Cadaver ulnas with and without midshaft dynamic compression plates are subjected to a static ...