Stress field interaction and strain energy distribution between a stationary main crack and its process zone

1998 ◽  
Vol 59 (6) ◽  
pp. 797-814 ◽  
Author(s):  
Antonio Brencich ◽  
Alberto Carpinteri
Keyword(s):  
Stress Field ◽  
Energy Distribution ◽  
Main Crack ◽  
Strain Energy ◽  
Process Zone ◽  
Field Interaction

Semi Empirical Stress Analysis of a Brittle Material in a Vicinity of a Stress Concentrator

2006 ◽  
Vol 3-4 ◽  
pp. 243-252 ◽  
Author(s):  
M. Chabaat ◽  
S. Djouder ◽  
M. Touati
Keyword(s):  
Stress Field ◽  
Main Crack ◽  
Process Zone ◽  
Crack Opening ◽  
Damage Zone ◽  
Local Stress ◽  
Complex Problem ◽  
Solution Procedure ◽  
Semi Empirical ◽  
Interaction Problem

In this study, interaction of a main crack with its surrounding damage, which consists of continuous lines of discontinuities, is analysed. To solve this complex problem, a Semi-Empirical Approach (SEA), which relies on experimentally measured crack opening displacements as the solution to this multiple crack interaction problem is suggested. The solution procedure is illustrated, first, for a particular case of the interaction of an array of horizontal and vertical crazes with a main crack, and second, for the generalized case to include the whole damage of crazing patterns surrounding the main crack. The results show that the crack Damage Zone (DZ) or the socalled Process Zone (PZ) interaction may either amplify or suppress the resulting stress field depending on the crack damage configuration. Green’s function for the Stress Intensity Factor (SIF) is employed to quantify the effects on a crack of the damage of continuous patterns of discontinuities. It follows from the analysis that an increase in the number of crazing patterns will amplify the stress at the main crack. It is also shown throughout this study that the overall effect of the damage is identified, as being an amplifying one and that the resulting local stress field would direct the propagation of the main crack since there is no toughening.

Analysis of Energy Balance When Using Cohesive Zone Models to Simulate Fracture Processes

2002 ◽  
Vol 124 (4) ◽  
pp. 440-450 ◽  
Author(s):  
C. Shet ◽  
N. Chandra
Keyword(s):  
Cohesive Energy ◽  
Cohesive Zone ◽  
Strain Energy ◽  
Fracture Process ◽  
Fracture Process Zone ◽  
Process Zone ◽  
Elastic Strain Energy ◽  
Inelastic Strain ◽  
External Work ◽  
Cohesive Zone Models

Cohesive Zone Models (CZMs) are being increasingly used to simulate fracture and fragmentation processes in metallic, polymeric, and ceramic materials and their composites. Instead of an infinitely sharp crack envisaged in fracture mechanics, CZM presupposes the presence of a fracture process zone where the energy is transferred from external work both in the forward and the wake regions of the propagating crack. In this paper, we examine how the external work flows as recoverable elastic strain energy, inelastic strain energy, and cohesive energy, the latter encompassing the work of fracture and other energy consuming mechanisms within the fracture process zone. It is clearly shown that the plastic energy in the material surrounding the crack is not accounted in the cohesive energy. Thus cohesive zone energy encompasses all the inelastic energy e.g., energy required for grainbridging, cavitation, internal sliding, surface energy but excludes any form of inelastic strain energy in the bounding material.

Partial Strain Energy Release Rate for Study Matrix Cracking Evolution in Composite Cross-Ply Laminates

2015 ◽  
Vol 24 (3) ◽  
pp. 096369351502400
Author(s):  
Jean-Luc Rebière
Keyword(s):  
Stress Field ◽  
Composite Laminates ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Matrix Cracking ◽  
Damage State ◽  
Damage Process ◽  
Cracking Mechanisms ◽  
Observed Damage

Matrix cracking is generally the first observed damage in composite laminates. The stress field distribution in the damaged cross ply laminates is analysed through an approach which uses several hypotheses to simplify the damage state. The proposed cracking criterion involves the respective partial part of the 0° and 90° layers to the damage process. The initiation of transverse and longitudinal cracking mechanisms is predicted.

Finite Axisymmetric Deformations of Initially Cylindrical Reinforced Membranes

1972 ◽  
Vol 45 (6) ◽  
pp. 1677-1683 ◽  
Author(s):  
A. D. Kydoniefs
Keyword(s):  
Stress Field ◽  
Internal Pressure ◽  
Energy Function ◽  
Strain Energy ◽  
Strain Energy Function ◽  
Incompressible Material ◽  
Parameter System ◽  
Axial Section ◽  
Variable Pitch ◽  
Two Parameter

Abstract We consider the axisymmetrie deformations of an initially cylindrical membrane composed of an elastic, homogeneous, isotropic and incompressible material reinforced with a two-parameter system of perfectly flexible and inextensible helicoidal cords of variable pitch. The undeformed configuration is determined so that the deformed membrane has a given axial section under specified internal pressure. The corresponding stress field and cord tensions are obtained. The solution given is exact and valid for the general form of the strain—energy function.

The Modal Analysis for the Separate Frame Construction of a SUV

2011 ◽  
Vol 130-134 ◽  
pp. 365-368
Author(s):  
Feng Huang ◽  
Li Juan Wang ◽  
Zong Yu Chen ◽  
Li Du
Keyword(s):  
Finite Element ◽  
Energy Distribution ◽  
Strain Energy ◽  
Vibration Mode ◽  
Dynamic Performance ◽  
Element Model ◽  
Body Structure ◽  
Modal Strain Energy ◽  
Frame Construction ◽  
The Finite Element Model

The market share for sport utility vehicles is becoming increasingly very fast in recent years. Many auto companies are stepping up the work of research and development the new model of SUV. A new SUV body modal is studied in this paper. The finite element model of the SUV frame is built by the HyperMesh and the SUV frame modal is researched by the Nastran. Low-order vibration mode and the first bending and torsion modal strain energy distribution of the SUV body structure are obtained, and the SUV body structure of the dynamic performance was assessed in this paper.

A circular disc containing a radial edge crack opened by a constant internal pressure

1977 ◽  
Vol 81 (3) ◽  
pp. 497-521 ◽  
Author(s):  
R. D. Gregory
Keyword(s):  
Stress Concentration ◽  
Stress Field ◽  
Internal Pressure ◽  
Plane Stress ◽  
Edge Crack ◽  
Strain Energy ◽  
Circular Disc ◽  
Total Strain Energy ◽  
Significant Figures ◽  
Image Position

AbstractA circular disc of radius a, made of homogeneous, isotropic, linearly elastic material, contains a radial edge crack of length b(0 < b < 2a). The disc is in equilibrium in a state of generalized plane stress caused by loading the faces of the crack by a constant internal pressure. The problem of determining the resulting stress field throughout the disc is solved analytically in closed form. The principal results are that the stress concentration factor at the crack tip, the total strain energy W, and the opening U at the mouth of the crack, are given exactly bywhere A is a constant whose value correct to 6 significant figures isand , W0, U0 are normalising factors defined in section 6.

Complex Variable Green’s Functions for Crack-Microcracks Interactions

2011 ◽  
Vol 465 ◽  
pp. 123-128 ◽  
Author(s):  
M. Chabaat ◽  
H. Ayas
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Stress Field ◽  
Main Crack ◽  
Green's Functions ◽  
Green’S Functions ◽  
Complex Variables ◽  
Mode I ◽  
Micro Cracks

In this study, interaction between a main crack and a surrounding layer of micro cracks is considered. A stress field distribution induced during these interactions is obtained using Muskhelshvili’s complex variables formalism which relies on the Green's functions. The effect of amplification and shielding on the resulting stress field is shown, herein, through a study of mode I Stress Intensity Factor (SIF). To quantify these effects, orientations as well as positions of microcracks with respect to the main crack is taken into consideration. Obtained results are compared and agreed with those of other researchers.

Does the Process Zone Control Crack Growth?

1992 ◽  
Vol 45 (8) ◽  
pp. 367-376 ◽  
Author(s):  
H. Abe´ ◽  
M. Saka ◽  
S. Ohba ◽  
T. Hashida
Keyword(s):  
Crack Growth ◽  
Main Crack ◽  
Fracture Process ◽  
Fracture Process Zone ◽  
Process Zone ◽  
Crack Tip ◽  
Compact Tension ◽  
Initial Crack ◽  
Zone Control ◽  
Notch Length

Fracture toughness tests were carried out by using small compact tension specimens of Westerly granite. Relation between the load-line displacement and the initial crack-tip separation changed from linear to nonlinear and then to linear again with increasing loading. The onset of the main crack growth was found to occur in a loading level at which the relation was nonlinear. This result disclosed that the onset of main crack growth in granite occurred without experience of the complete area under the tension-softening curve. The critical value of the initial crack-tip separation for onset of the main crack growth was obtained independently of the initial notch length. Also monitoring of the growth of the fracture process zone by ultrasonic technique showed that its length related with the crack-tip separation independently of the initial notch length. By combining the results just mentioned, it was concluded that the fracture process zone controlled the onset of the main crack growth.

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