A Continuum Damage Model for Fracture of Brittle Solids Under Dynamic Loading

1991 ◽  
Vol 58 (4) ◽  
pp. 904-909 ◽  
Author(s):  
E. P. Fahrenthold

A continuum damage mechanics description of elastic-brittle fracture provides an appropriate constitutive model for impact simulations involving ceramic, rock, or similar materials. For an orthotropically damaged solid, a complementary energy function may be derived from a mesomechanical description of three orthogonal arrays of coalescing cracks. Damage evolution equations suggested by dynamic fracture test measurements may be expressed in terms of tensor power functions which generalize classical one-dimensional analyses. Measured Weibull strength distributions may be employed to account for flaw size distribution effects on the damage accumulation rate. The resulting model avoids the introduction of effective stress assumptions or the use of specialized material property coefficients obtained from nonstandard mechanical tests.

2012 ◽  
Vol 498 ◽  
pp. 42-54 ◽  
Author(s):  
S. Benbelaid ◽  
B. Bezzazi ◽  
A. Bezazi

This paper considers damage development mechanisms in cross-ply laminates using an accurate numerical model. Under static three points bending, two modes of damage progression in cross-ply laminates are predominated: transverse cracking and delamination. However, this second mode of damage is not accounted in our numerical model. After a general review of experimental approaches of observed behavior of laminates, the focus is laid on predicting laminate behavior based on continuum damage mechanics. In this study, a continuum damage model based on ply failure criteria is presented, which is initially proposed by Ladevèze. To reveal the effect of different stacking sequence of the laminate; such as thickness and the interior or exterior disposition of the 0° and 90° oriented layers in the laminate, an equivalent damage accumulation which cover all ply failure mechanisms has been predicted. However, the solution algorithm using finite element analysis which implements progressive failure analysis is summarized. The results of the numerical computation have been justified by the previous published experimental observations of the authors.


2004 ◽  
Vol 72 (4) ◽  
pp. 553-557 ◽  
Author(s):  
D. Cope ◽  
S. Yazdani ◽  
J. W. Ju

In continuum damage mechanics theories, damage functions are identified based on experimental records. These functions also serve as strain hardening-softening functions similar to the conventional plasticity formulations. In a class of damage theories described in this paper it will be shown that if care is not taken, internal contradictions will arise as manifested by a snapback in the strain–stress space. This paper establishes a formal method by which different damage functions can consistently be developed leading to no snap-back in the solution.


1999 ◽  
Vol 67 (1) ◽  
pp. 193-196 ◽  
Author(s):  
G. J. Rodin

It is shown that the original continuum damage mechanics model of Kachanov is better suited for creep life analysis of creep-brittle solids and structures than continuum damage mechanics models that take into account damage-induced softening. [S0021-8936(00)03001-4]


1990 ◽  
Vol 112 (4) ◽  
pp. 412-421 ◽  
Author(s):  
C. L. Chow ◽  
K. Y. Sze

A recently developed anisotropic model of continuum damage mechanics has been applied successfully to characterize ductile fracture of cracked plates under mode I and mixed mode failures. The damage model is further extended in this investigation to examine its applicability to include notch ductile fracture of thin plates containing a circular hole. Two hole sizes of 16 mm and 24 mm diameters are chosen and the specimen material is aluminum alloy 2024-T3. Fracture loads of the plates are predicted by the damage model and compared satisfactorily with those determined experimentally. This investigation provides an important confirmation that not only the anisotropic model of continuum damage mechanics but also the same failure criterion developed can be effectively employed to characterize both ductile fracture for plates containing an isolated macro-crack or circular hole which would otherwise not be possible using the conventional theory of fracture mechanics. The successful development of the unified approach to characterize ductile failure provides a vital impetus for design engineers in the general application of the theory of continuum damage mechanics to solve practical engineering problems.


2013 ◽  
Vol 05 (04) ◽  
pp. 1350038 ◽  
Author(s):  
H. YAZDANI ◽  
A. NAYEBI

Ratcheting and fatigue damage of thin-walled tube under cyclic bending and steady internal pressure is studied. Chaboche's nonlinear kinematic hardening model extended by considering the effect of continuum damage mechanics employed to predict ratcheting. Lemaitre damage model [Lemaitre, J. and Desmorat, R. [2005] Engineering Damage Mechanics (Springer-Verlag, Berlin)] which is appropriate for low cyclic loading is used. Also the evolution features of whole-life ratcheting behavior and low cycle fatigue (LCF) damage of the tube are discussed. A simplified method related to the thin-walled tube under bending and internal pressure is used and compared well with experimental results. Bree's interaction diagram with boundaries between shakedown and ratcheting zone is determined. Whole-life ratcheting of thin-walled tube reduces obviously with increase of internal pressure.


2011 ◽  
Vol 194-196 ◽  
pp. 919-923 ◽  
Author(s):  
Dong Fang Pan ◽  
Yun Feng Qiao ◽  
Cheng Shuai Sun ◽  
Xue Bing Liu

To propose the damage model of concrete in the freezing-thawing cycles, the reasonable dissipation function and micro plastic deformation expression have been determined based on the continuum damage mechanics. The damage variable is expressed as a function of the number of freezing-thawing cycle. The damage is defined in terms of the loss of the dynamic elastic modules and the damage model of the concrete in the freezing-thawing cycles has been presented.


2013 ◽  
Vol 683 ◽  
pp. 176-181
Author(s):  
Yong Chen ◽  
Bao Jun Pang ◽  
Wei Zheng

In order to establish an elastic damage model for S2-glass/epoxy composite and identify the input parameters, in-plane behaviour of the composite including tensile, compression and tensile shear were investigated through series of tests. Concerning no plasticity, a simple elastic ply damage mechanics model for this composite was characterized based on Continuum Damage Mechanics Model (CDM) and the input parameters were obtained. The model was then implemented into ABAQUS/EXPLICT and the results show the model can capture most of the in-plane behaviour of the composite material.


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