Bond failure of a SiC/SiC brazed assembly

International Journal of Solids and Structures

2018

Until now, the coupled stress and energy criterion has mainly been used in 2D applications, but it is possible to extend it to a 3D case. Herein the crack initiation in epoxy/aluminum bimaterial specimens under four point bending is predicted through a 3D numerical application of the coupled criterion. The stress and the energy conditions are computed by means of 3D finite element modeling of both undamaged and cracked specimens. The crack initiates at the epoxy/aluminum interface, meshes of the cracked specimens take into account the crack topology which is determined using the interface normal stress isocontours. By indirect confrontation to experimental tests on aluminum/epoxy bimaterial specimens of different width, the proposed approach allows determining the interface strength and fracture energy. The blind application of the proposed method to a crack initiation in aluminum/epoxy/aluminum specimens of different epoxy layer thickness under four point bending leads to a reasonable agreement with experimental data.

Section: Aluminum-epoxy-aluminum Specimensmentioning

confidence: 97%

3D application of the coupled criterion to crack initiation prediction in epoxy/aluminum specimens under four point bending

Doitrand

International Journal of Solids and Structures

2018

“…Many applications of the CC can be found in the literature with a wide range of structural applications including free-edge delamination, transverse cracking and notched strength of composite laminates [36][37][38][39][40][41], adhesive and brazed joints [42][43][44][45][46][47][48], crack onset at Vnotches [49][50][51], cracking in ceramic laminates [52][53][54]. An overview of applications and an extensive list of references can be found in review papers [55][56].…”

Section: The Coupled Criterionmentioning

confidence: 99%

A finite fracture model for the analysis of multi-cracking in woven ceramic matrix composites

Martín

Composites Part B: Engineering

et al. 2018

Self Cite

:A finite fracture approach based on the Coupled Criterion is used to analyze multi-cracking in a woven ceramic matrix composite. In-situ micrographic observations obtained during tensile and bending tests performed on chemical vapor infiltrated SiC/SiC samples are utilized to identify cracking mechanisms. A two dimensional finite element model is generated to approximate the actual specimen section geometry including matrix, fiber tows and porosity. Numerical simulations are carried out with a dedicated algorithm to simulate nucleation and propagation of cracks. Comparing the simulation results with experimental ones shows that the model captures the main cracking features.

“…Afterward, the CC gets increasing popularity in fracture prediction of brittle or quasi-brittle materials. A large number of cases were studied by using this criterion (Nguyen et al 2012;Mantic, 2009;Martin et al 2010;Leguillon, 2011;Leguillon and Yosibash, 2003;Tran et al, 2012 among others).…”

Section: Introductionmentioning

confidence: 99%

Numerical implementation of the coupled criterion for damaged materials

International Journal of Solids and Structures

Martín

et al. 2019

In this work, we present a numerical model to deal with the fracture of damaged materials within the framework of the finite fracture mechanics (FFM). Continuum damage mechanics combined with the regularization techniques is first applied to determine the damage field. The transition from continuous damage field to discontinuous crack occurs when the coupled criterion (CC) is fulfilled. Special numerical algorithms were developed in crack path tracking and crack creation for the analysis of the entire failure process from damage development to crack creation.Both initiation and growth of one or multiple cracks can reasonably be simulated and efficiency and accuracy of the approach are illustrated through several numerical examples.