𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Crack growth resistance behavior of a functionally graded material: computational studies

✍ Scribed by Z.-H. Jin; R.H. Dodds Jr.


Publisher
Elsevier Science
Year
2004
Tongue
English
Weight
589 KB
Volume
71
Category
Article
ISSN
0013-7944

No coin nor oath required. For personal study only.

✦ Synopsis


This paper describes crack growth resistance simulation in a ceramic/metal functionally graded material (FGM) using a cohesive zone ahead of the crack front. The plasticity in the background (bulk) material follows J 2 flow theory with the flow properties determined by a volume fraction based, elastic-plastic model (extension of the original Tamura-Tomota-Ozawa model). A phenomenological, cohesive zone model with six material-dependent parameters (the cohesive energy densities and the peak cohesive tractions of the ceramic and metal phases, respectively, and two cohesive gradation parameters) describes the constitutive response of the cohesive zone. Crack growth occurs when the complete separation of the cohesive surfaces takes place. The crack growth resistance of the FGM is characterized by a rising Jintegral with crack extension (averaged over the specimen thickness) computed using a domain integral (DI) formulation. The 3-D analyses are performed using WARP3D, a fracture mechanics research finite element code, which incorporates solid elements with graded elastic and plastic properties and interface-cohesive elements coupled with the functionally graded cohesive zone model. The paper describes applications of the cohesive zone model and the DI method to compute the J resistance curves for both single-edge notch bend, SE(B), and single-edge notch tension, SE(T), specimens having properties of a TiB/Ti FGM. The numerical results show that the TiB/Ti FGM exhibits significant crack growth resistance behavior when the crack grows from the ceramic-rich region into the metal-rich region. Under these conditions, the J -integral is generally higher than the cohesive energy density at the crack tip even when the background material response remains linearly elastic, which contrasts with the case for homogeneous materials wherein the J -integral equals the cohesive energy density for a quasi-statically growing crack.


πŸ“œ SIMILAR VOLUMES


Geometry update driven by material force
✍ Rolf Mahnken πŸ“‚ Article πŸ“… 2009 πŸ› John Wiley and Sons 🌐 English βš– 1011 KB

## Abstract Functionally graded materials (FGMs) are advanced materials that possess continuously graded properties, such that the growth of cracks is strongly dependent on the gradation of the material. In this work a thermodynamic consistent framework for crack propagation in FGMs is presented, b

Thermal fracture resistance of a functio
✍ Z.-H. Jin; Y.Z. Feng πŸ“‚ Article πŸ“… 2008 πŸ› Elsevier Science 🌐 English βš– 615 KB

This work investigates the thermal fracture resistance of a functionally graded coating with an array of periodic edge cracks. The integral equation method is used to analyze the thermal stress intensity factors (TSIFs) at the crack tips and the critical thermal shocks that cause crack initiation. T

On the modal behavior of a three-dimensi
✍ Ganesh Anandakumar; Jeong-Ho Kim πŸ“‚ Article πŸ“… 2010 πŸ› Elsevier Science 🌐 English βš– 884 KB

element method Rayleigh-Ritz method Poisson's ratio effects Gaussian integration formulation a b s t r a c t Modal behavior of a three-dimensional (3D) homogeneous and functionally graded (FG) cantilever beam is studied using the Rayleigh-Ritz (RR) method and the finite element method (FEM). The eff