This study computationally and experimentally examines the mechanisms of crack penetration, deflection and the transition between penetration and deflection. The finite element analysis based computational modeling work used strength-and-energy based cohesive-zone approach to study the effect of dimensionless parameters (e.g., interfacial incident angle, fracture-length scale, and normalized toughness) on penetration/deflection...
The advent of synthetic adhesives has transformed the structural applications of wood. However, a persistent issue in adhesively-bonded wood products has been moisture durability. When designing wood based composites, moisture durability will depend on both the wood phase and the adhesive phase. A key question, therefore, is how does one...
Three approaches for evaluating mode I interlaminar strain energy release rates in graphite/epoxy composites were compared using experimental data from double cantilever beam specimens. Expressions for evaluating strain energy release rates were arrived at based on assumptions regarding specimen geometry and material behavior. The calculations included the direct method of...
Silver interlayers between maraging steel base metal were examined to evaluate mechanisms leading to ductile failure in constrained thin metals. The constraint of the maraging steel base metal during uniaxial testing of constrained thin silver results in a large hydrostatic tension component, a small von Mises effective stress, and negligible...
The problem of determining whether a crack impinging on an interface will penetrate into the substrate or deflect along the interface is vital to the effective design of layered and composite material systems. Of particular interest is the transition between crack propagation by penetration through an interface and deflection along...
The purpose of this thesis was to evaluate orthogonal cutting as a method to determine the fracture toughness of low and high density polyethylene and wood plastic composites. A test fixture was developed to capture normal and tangential cutting forces at variable depth and rake angle. A tool interface method...
Wave dispersion and fracture are phenomena that involve. mechanisms triggered at the scale of a material's internal structure. Experiments were performed with a candidate material to judge the hypothesis that wave dispersion measurements can be used to nondestructively predict fracture strength. Wood-based particleboard was chosen as the candidate material because...