Infinite Cylinder with an Internal Crack and Two Inclusions

In order to investigate the fatigue cracking resistance of engineered cementitious composites (ECC) used in in total life pavement, the semi-circular bending (SCB) test and improved three-point bending fatigue test (ITBF) were utilized in this study. The digital image correlation (DIC) method was also utilized to track the surface strain fields of specimens during the SCB test. X-ray computed tomography (CT) and digital image processing (DIP) technologies were applied to measure the internal-crack distribution of the ITBF specimen. The results of the SCB test showed that the fatigue cracking damage process of ECC can be divided into three stages and that the cracking stable propagating stages occupied the main part, which indicates that ECC has excellent ductility and toughness and could work very well with existing cracks. The ITBF results showed that the fatigue cracking resistance of ECC was better than epoxy asphalt concrete (EAC). In addition, the internal-crack distribution along the depth direction of the ITBF specimen could be presented well by the image pixel statistical (IPS) method based on CT scanning of image slices. It could be found that multiple cracks propagate simultaneously in ECC, instead of a single crack, under the OSBD pavement working condition.

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Delamination of Compressively Stressed Orthotropic Functionally Graded Material Coatings Under Thermal Loading

Journal of Applied Mechanics ◽

10.1115/1.2936239 ◽

2008 ◽

Vol 75 (5) ◽

Cited By ~ 8

Author(s):

Bora Yıldırım ◽

Suphi Yılmaz ◽

Suat Kadıoğlu

Keyword(s):

Functionally Graded Material ◽

Bond Coat ◽

Thermal Loading ◽

Layer Structure ◽

Crack Problem ◽

Functionally Graded ◽

Internal Crack ◽

Correlation Technique ◽

Fracture Parameters ◽

Graded Material

The objective of this study is to investigate a particular type of crack problem in a layered structure consisting of a substrate, a bond coat, and an orthotropic functionally graded material coating. There is an internal crack in the orthotropic coating layer. It is parallel to the coating bond-coat interface and perpendicular to the material gradation of the coating. The position of the crack inside the coating is kept as a variable. Hence, the case of interface crack is also addressed. The top and bottom surfaces of the three layer structure are subjected to different temperatures and a two-dimensional steady-state temperature distribution develops. The case of compressively stressed coating is considered. Under this condition, buckling can occur, the crack can propagate, and the coating is prone to delamination. To predict the onset of delamination, one needs to know the fracture mechanics parameters, namely, Mode I and Mode II stress intensity factors and energy release rates. Hence, temperature distributions and fracture parameters are calculated by using finite element method and displacement correlation technique. Results of this study present the effects of boundary conditions, geometric parameters (crack length and crack position), and the type of gradation on fracture parameters.

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Modelling of vibration of beam in presence of inclined edge or internal crack for its possible detection based on frequency measurements

Engineering Fracture Mechanics ◽

10.1016/s0013-7944(97)00078-7 ◽

1997 ◽

Vol 58 (3) ◽

pp. 193-205 ◽

Cited By ~ 60

Author(s):

B.P. Nandwana ◽

S.K. Maiti

Keyword(s):

Internal Crack ◽

Frequency Measurements

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Elastic-Plastic Analysis of an Elbow With Axial Part-Through Internal Crack at Crown Under In-Plane Bending

Volume 3: Design and Analysis ◽

10.1115/pvp2008-61452 ◽

2008 ◽

Author(s):

K. M. Prabhakaran ◽

S. R. Bhate ◽

V. Bhasin ◽

A. K. Ghosh

Keyword(s):

Finite Element ◽

Crack Depth ◽

Bending Moment ◽

Internal Crack ◽

J Integral ◽

Finite Element Analyses ◽

Integrity Assessment ◽

Elastic Plastic ◽

Axial Part ◽

Plane Bending

Piping elbows under bending moment are vulnerable to cracking at crown. The structural integrity assessment requires evaluation of J-integral. The J-integral values for elbows with axial part-through internal crack at crown under in-plane bending moment are limited in open literature. This paper presents the J-integral results of a thick and thin, 90-degree, long radius elbow subjected to in-plane opening bending moment based on number of finite element analyses covering different crack configurations. The non-linear elastic-plastic finite element analyses were performed using WARP3D software. Both geometrical and material nonlinearity were considered in the study. The geometry considered were for Rm/t = 5, and 12 with ratio of crack depth to wall thickness, a/t = 0.15, 0.25, 0.5 and 0.75 and ratio of crack length to crack depth, 2c/a = 6, 8, 10 and 12.

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An analysis of the elastic interaction between an edge dislocation and an internal crack

Materials Science and Engineering A ◽

10.1016/0921-5093(90)90074-d ◽

1990 ◽

Vol 130 (1) ◽

pp. 1-10 ◽

Cited By ~ 24

Author(s):

Shing-Dar Wang ◽

Sanboh Lee

Keyword(s):

Edge Dislocation ◽

Elastic Interaction ◽

Internal Crack

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The viscous secondary flow ahead of an infinite cylinder in a uniform parallel shear flow

Journal of Fluid Mechanics ◽

10.1017/s0022112060000098 ◽

1960 ◽

Vol 7 (1) ◽

pp. 145-155 ◽

Cited By ~ 5

Author(s):

Alar Toomre

Keyword(s):

Shear Flow ◽

Lateral Displacement ◽

Reynolds Numbers ◽

Infinite Cylinder ◽

List Type ◽

Displacement Effect ◽

Simple Method ◽

Viscous Shear ◽

Parallel Shear Flow ◽

Viscous Shear Flow

A simple method is presented in this paper for calculating the secondary velocities, andthe lateral displacement of total pressure surfaces (i.e. the ‘displacement effect’) in the plane of symmetry ahead of an infinitely long cylinder situated normal to a steady, incompressible, slightly viscous shear flow; the cylinder is also perpendicular to the vorticity, which is assumed uniform but small. The method is based on lateral gradients of pressure, these being calculated from the primary flow alone. Profiles of the secondary velocities are obtained at several Reynolds numbers ahead of two specific cylindrical shapes: a circular cylinder, and a flat plate normal to the flow. The displacement effect is derived and, rathe surprisingly, is found to be virtually independent of the Reynolds number.

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