Microstructure Fracture Behavior Research Articles

Effect of Asphalt Mortar Viscoelasticity on Microstructural Fracture Behavior of Asphalt Mixture Based on Cohesive Zone Model

Effect of Asphalt Mortar Viscoelasticity on Microstructural Fracture Behavior of Asphalt Mixture Based on Cohesive Zone Model

Effects of Nonuniform Fiber Geometries on the Microstructural Fracture Behavior of Ceramic Matrix Composites

Microstructural fracture behavior of a ceramic matrix composite (CMC) with nonuniformly distributed fibers is studied in the presentation. A comprehensive numerical analysis package to study the effect of nonuniform fiber dimensions and locations on the microstructural fracture behavior is developed. The package starts with an optimization algorithm for generating representative volume element (RVE) models that are statistically equivalent to experimental measurements. Experimentally measured statistical data are used as constraints while the optimization algorithm is running. Virtual springs are utilized between any adjacent fibers to nonuniformly distribute the coated fibers in the RVE model. The virtual spring with the optimization algorithm can efficiently generate multiple RVEs that are statistically identical to each other. Smeared crack approach (SCA) is implemented to consider the fracture behavior of the CMC material in a mesh-objective manner. The RVEs are subjected to tension as well as the shear loading conditions. SCA is capable of predicting different fracture patterns, uniquely defined by not only the fiber arrangement but also the specific loading type. In addition, global stress-strain curves show that the microstructural fracture behavior of the RVEs is highly dependent on the fiber distributions.

Development of Numerical Tool for Analysis of Microstructural Fracture Behavior in Smart & Intelligent Materials

As a numerical tool for examining the microstructural fracture behavior in the smart and intelligent materials, a finite element method with the interface element was developed and the applicability of this method was studied through the serial computations using virtual polycrystalline models. As the results assuming the influence of grain orientation on the grain boundary, it was found that the anisotropic mechanical property of grain boundary (interaction between opening and slipping deformations) would be a dominant factor of the fracture process. Also, by employing the theory of crystal plasticity for the mechanical property of grain, it was revealed that the stress concentrations caused by both the mismatch between neighbor grains and the slipping at grain boundary could be demonstrated by using this method.

Preliminary Numerical Research of Microstructural Fracture Behavior in Metal by Using Interface Element

In order to demonstrate not only the deformation of grain but also the opening and/or sliding at grain boundary, the interface element was introduced into the ordinary finite element method, and this numerical method was applied for examining the microstructural fracture behavior in two-dimensional ideal microstructure obtained through Voronoi tessellations. As for the grain, the anisotropy in elastic modulus due to the grain orientation was taken into account, while the fracture strength at grain boundary was assumed to be related to the boundary energy which could be determined by the atomic disorder at the boundary. From the serial computational results for examining the influences of elastic properties in grain (isotropy and anisotropy), mechanical property at grain boundary (interaction between opening and sliding deformation), and grain configurations, it was revealed that all the factors varied in this research might affect the microstructural fracture behavior. Also, it can be concluded that this numerical method with the interface element can be useful for demonstrating the microstructural fracture behavior including the deformation at grain boundary.

Basic Analysis of Microstructural Fracture Behavior in Structural Materials by Using FEM with Interface Element

A new finite element method with the interface element was developed for examining the microstructural fracture behavior, where the anisotropy of grain was modeled by the ordinary finite element while both the opening and shear deformations was demonstrated by the interface element. From the serial computations using two-dimensional virtual polycrystalline models obtained through Voronoi tessellations, it was found that the interaction between the interaction between opening and shear deformations would be a dominant factor of the fracture processes. Also, it can be concluded that this method would be a useful tool for examining microstructural fracture behavior. © 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of ICM11