Spontaneous Crack Propagation Along Functionally Graded Bimaterial Interfaces

2006 ◽  
Author(s):  
Dhirendra V. Kubair ◽  
B. Bhanu-Chandar
Keyword(s):  
Crack Propagation ◽  
Material Property ◽  
Material Properties ◽  
Propagation Speed ◽  
Functionally Graded ◽  
Hardening Material ◽  
Property Variation ◽  
Material Inhomogeneity ◽  
Crack Propagation Speed ◽  
Mode 3

The effects of spatially varying the material properties on the mode-3 planar crack propagation characteristics are numerically investigated. The spectral scheme that is available for homogeneous materials is modified to account for the asymmetrically varying material properties. Crack propagation along the interface of a functionally graded bimaterial system has been simulated. A parametric study was performed by systematically varying the material inhomogeneity length scale independently in the two half-spaces. Our study indicated that softening type graded materials reduce the resistance to fracture, while a hardening material offers higher fracture resistance with increase in inhomogeneity. Only the transient phase of crack propagation speed was affected by the material property variation, irrespective of whether the material was hardening, softening or an asymmetric type. The crack always reached a quasi-steady-state velocity, which remained unaffected by the material property inhomogeneity.

Elastic wave propagation in 2D-FGM hollow cylinders with curved outer surface under moving shock loading using isogeometric analysis

2020 ◽  
pp. 095440622096076
Author(s):  
Ahmad Yavari ◽  
Mohammad Hossein Abolbashari ◽  
Behrooz Hassani
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Hollow Cylinder ◽  
Outer Surface ◽  
Material Properties ◽  
Shock Loading ◽  
Propagation Speed ◽  
Elastic Field ◽  
Functionally Graded ◽  
Elastic Wave Propagation

Analysis of elastic wave propagation in a hollow cylinder with two-dimensional (2D) functionally graded material (FGM) and the curved outer surface under internal moving shock loading is the subject of this study. In the proposed method, there is no restriction on the distribution of material properties, the shape of the outer surface, and the applied shock loading. They are treated with non-uniform rational B-spline (NURBS). The isogeometric approach is developed for solving the problem to ensure precise modeling of the geometry. Also, the Newmark approach is used for full discretization of the isogeometric equations. The distributions of all elastic field quantities are determined for two types of material distributions and shock loadings. The effects of shock loadings, the shape of the outer surface, and the material distribution on the elastic wave are thoroughly examined. Propagation, reflections, and propagation speed inside the hollow cylinder are investigated. It is found that the propagation speeds of elastic waves have a distribution associated with the distribution of the material properties. Also, the shape of the outer surface can affect the amplitude of the elastic wave and the locations of concentration stress. It is concluded that the sonic boom phenomenon occurs in the solids as well as in the air.

scholarly journals Crack propagation speed in ceramic during quenching

2018 ◽  
Vol 38 (7) ◽  
pp. 2879-2885 ◽  
Author(s):  
Yingfeng Shao ◽  
Boyang Liu ◽  
Xiaohuan Wang ◽  
Long Li ◽  
Jiachen Wei ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Propagation Speed ◽  
Crack Propagation Speed

Effects of material property variation in composite panels

2017 ◽  
Vol 89 (2) ◽  
pp. 274-279
Author(s):  
Thomas Wright ◽  
Imran Hyder ◽  
Mitchell Daniels ◽  
David Kim ◽  
John P. Parmigiani
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Material Property ◽  
Material Properties ◽  
Damage Model ◽  
Element Model ◽  
Maximum Load ◽  
Content Type ◽  
Property Variation ◽  
Load Carrying

Purpose The purpose of this paper is to determine which of the ten material properties of the Hashin progressive damage model significantly affect the maximum load-carrying ability of center-notched carbon fiber panels under in-plane tension and out-of-plane bending. Design/methodology/approach The approach used is to calculate the maximum load using a finite element model for a range of material property values as specified by a fraction factorial design. The finite element model used has been experimentally validated in prior work. Findings Results showed that for the laminates considered, at most three and as few as one of the ten Hashin material properties significantly affected the magnitude of the maximum load. Practical implications While the results of this paper only specifically apply to the laminates included in the study, the results suggest that, in general, only a small number of the Hashin material properties affect laminate load-carrying ability. Originality/value Knowing which properties are significant is of value in selecting materials to optimize performance and also in determining which properties need to be known to a high accuracy.

Effect of Contact between the Crack Faces on Crack Propagation

2013 ◽  
Vol 577-578 ◽  
pp. 61-64 ◽  
Author(s):  
Guido Dhondt
Keyword(s):  
Crack Propagation ◽  
Propagation Speed ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Contact Conditions ◽  
Contact Formulation ◽  
Positive Mode ◽  
Crack Propagation Speed ◽  
Crack Faces ◽  
Realistic Prediction

In mixed-mode crack propagation the crack faces frequently touch each other. The ensuing friction is expected to decrease the crack propagation speed. This effect is usually not taken into account, however, a realistic prediction of this effect may increase the calculated life and consequently increase the length of the inspection intervals. In this paper, penalty contact conditions are introduced in between the crack faces of the automatically generated mesh in a cyclic crack propagation. Special attention is given to the contact formulation and the area in which contact is defined. It is shown that the resulting crack propagation rate is significantly reduced by the introduction of friction provided that positive Mode-I is not significantly involved.

Development of New IMO Type B Tank Based on the Results of Cryogenic Material Property Tests

2011 ◽  
Author(s):  
Kwang Seok Kim ◽  
Chang Youl Park ◽  
Joong Kyoo Kang
Keyword(s):  
Thermal Stress ◽  
Crack Propagation ◽  
Material Property ◽  
Material Properties ◽  
Fracture Analysis ◽  
Design Concept ◽  
Type B ◽  
Near Future

As the LNG industry is rapidly growing, the demand of FLNG (Floating LNG) is also increasing. Since the medium to long-term forecasts predict a shortage of LNG supply, the introduction of offshore LNG production can be seen in the near future. In recent, DSME has developed the new IMO type B tank (ACTIB: Aluminum Cargo Tank Independent type B) considering the cryogenic material properties. This paper describes engineering works done during the ACTIB development. A lot of engineering works were carried out from the basic scantling of the tank to characteristic works for IMO type B tank such as thermal stress, crack propagation & fracture analysis and leak & drip tray design concept. As a result of study, DSME received AIP from DNV and could unveil the ACTIB to the market.

DYNAMIC CRACK PROPAGATION IN A FUNCTIONALLY GRADED PIEZOELECTRIC INTERFACE LAYER BETWEEN TWO DISSIMILAR PIEZOELECTRIC LAYERS UNDER ELECTROMECHANICAL LOADING

2012 ◽  
Vol 06 ◽  
pp. 55-60
Author(s):  
JEONG WOO SHIN ◽  
YOUNG-SHIN LEE
Keyword(s):  
Crack Propagation ◽  
Material Properties ◽  
Integral Transform ◽  
Interface Layer ◽  
Functionally Graded ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Crack Plane ◽  
Piezoelectric Layers ◽  
Functionally Graded Piezoelectric

The dynamic propagation of a crack in a functionally graded piezoelectric material (FGPM) interface layer between two dissimilar piezoelectric layers under anti-plane shear is analyzed using the integral transform approaches. The properties of the FGPM layers vary continuously along the thickness. FGPM layer and the two homogeneous piezoelectric layers are connected weak-discontinuously. A constant velocity Yoffe-type moving crack is considered. Numerical values on the dynamic energy release rate (DERR) are presented for the FGPM. Followings are helpful to increase of the resistance of the crack propagation of the FGPM interface layer: (a) certain direction and magnitude of the electric loading; (b) increase of the thickness of the FGPM interface layer; (c) increase of the thickness of the homogeneous piezoelectric layer which has larger material properties than those of the crack plane in the FGPM interface layer. The DERR always increases with the increase of crack moving velocity and the gradient of the material properties.

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