Projects

NSF PATH (Functionally Graded Cement-Based Materials for Residential Construction)

This research project addresses the production of cement-based materials for residential construction using extrusion so as to produce functionally graded microstructures and then measure and compute the engineering properties provided by such microstructures.

I-FRANC (Illinois - FRacture ANalysis Code)

This code builds upon the FRANC code developed at Cornell University, and is specialized in fracture of functionally graded materials (FGMs). The code includes new graded elements, several methods to evaluate stress intensity factors, various micromechanics models, and also techniques for automatic crack propagation in FGMs.

FGM User Subroutine in ABAQUS

ABAQUS allows user to add user subroutines to achieve specific functionalities. Material subroutine UMAT is developed to account for material gradation at each gauss point of element level, and element subroutine UEL is developed for cohesive elements. Thsese subroutines are to be implemented to investigate Reflective Cracking problem in pavements and in general FGMs.

We are currently developing a two-dimensional boundary element code with adaptive mesh capabilities.  Written in MATLAB, this program will be able to take any two-dimensional geometry and loading condition and return the developed potential and flux (or stresses and strains) in the body.  A graphical interface simplifies the process of inputting the geometry and loading, and interpretation of the results.  Please follow the above link to a series of screen captures that will provide a more in depth look into BEAN.  BEAN is intended to be an education software and we hope it will help demystify the boundary element method.

FGM Optimization and TAP (Thermal Analysis Program)

Some of the current research in the group is focused on the fracture behavior of functionally graded materials subjected to both mechanical and thermal shock loads.   Macro- and micro-mechanics models are being developed that will be able to predict the thermo-mechanical responses of cracked FGMs. The aim is to determine the compositional profile in an FGM required to achieve optimized thermal fracture resistance of the material.  To this end, a program is being developed to model FGMs subjected to a thermal shock.  The name TAP standing for Thermal Analysis Program has been adopted for the program.  Like with BEAN, a graphic user interface is being developed for TAP to ease the use of this program.  When this is completed, a series of screen captures will be provided to give a more in depth look into TAP than is possible at this time.

FGM and the Finite Element Method

We are working on developing a finite element code that will be able to apply various types of material property gradations.  This program also has the ability to propagate cracks in FGMs!  The program I-FRANC that is being generated in the FGM group here at UIUC is incorporated into a previously established finite element program (FRANC2D).