Dynamic Fracture Toughness of a Plain Weave Carbon-Epoxy Composite: Validation of Test Results with Finite Element Analyses

The dynamic fracture behavior of 7075-T6 aluminum alloy was studied by finite element method to simulate a cracked three-point bending specimen loaded by stress wave loading. In order to determine the elastic-plastic dynamic fracture toughness using quasi-static fracture mechanics theory, the nominal load measured by Hopkinson pressure bar loaded fracture testing system was input into a finite element program to calculate the loading point displacement, and then this displacement was employed to obtain the load-displacement field in the vicinity of the crack tip without the inertia effect, the variation of J-integral as a function of time was established using the load-displacement parameters determined by finite element analysis. The critical J-integral corresponding to crack initiation time detected by a small strain gauge mounted on the three-point bending fracture specimen is determined as an elastic-plastic dynamic fracture toughness (JId). The comparison between the equivalent dynamic fracture toughness(KId) given by the aforementioned procedures and the value measured in previous studies was made to verify the validation of the proposed procedure.

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Research on Dynamic Fracture Toughness of Granite and Finite Element Analysis

Procedia Engineering ◽

10.1016/j.proeng.2012.04.211 ◽

2012 ◽

Vol 37 ◽

pp. 107-112 ◽

Cited By ~ 1

Author(s):

Gong Nengping ◽

Gao Yuan ◽

Jiang Xiangyang ◽

Luo Yufan

Keyword(s):

Fracture Toughness ◽

Finite Element Analysis ◽

Finite Element ◽

Dynamic Fracture ◽

Dynamic Fracture Toughness ◽

Element Analysis

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A New Mode Iii Delamination Test for Composites

Advanced Composites Letters ◽

10.1177/096369359200100501 ◽

1992 ◽

Vol 1 (5) ◽

pp. 096369359200100 ◽

Cited By ~ 10

Author(s):

P Robinson ◽

D Q Song

Keyword(s):

Finite Element ◽

Fracture Surface ◽

Epoxy Composite ◽

Test Method ◽

Mode Ii ◽

Test Results ◽

Finite Element Analyses ◽

Initial Test ◽

Beam Test ◽

Mode Iii

This letter reports a concept for a Mode III test method which eliminates the Mode II component experienced with the split cantilever beam test method. The success of the design is demonstrated by finite element analyses and by SEM fracture surface photographs. Initial test results are reported for a carbon fibre epoxy composite.

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An Evaluation of Analysis Methodologies for Predicting Cleavage Arrest of a Deep Crack in an RPV Subjected to PTS Loading Conditions

Journal of Pressure Vessel Technology ◽

10.1115/1.2929566 ◽

1994 ◽

Vol 116 (2) ◽

pp. 128-135

Author(s):

J. A. Keeney ◽

B. R. Bass

Keyword(s):

Fracture Toughness ◽

Finite Element ◽

Finite Element Model ◽

Dynamic Fracture ◽

Element Model ◽

Dynamic Fracture Toughness ◽

Loading Conditions ◽

Dynamic Finite Element ◽

Static Models ◽

Deep Crack

Several calculational procedures are compared for predicting cleavage arrest of a deep crack in the wall of a prototypical reactor pressure vessel (RPV) subjected to pressurized-thermal-shock (PTS) types of loading conditions. Three procedures examined in this study utilized the following models: 1) a static finite-element model (full bending); 2) a radially constrained static model; and 3) a thermo-elastic dynamic finite-element model. A PTS transient loading condition was selected that produced a deep arrest of an axially oriented initially shallow crack according to calculational results obtained from the static (full-bending) model. Results from the static models were compared with those generated from detailed thermoelastic dynamic finite-element analysis. The dynamic analyses modeled cleavage-crack propagation using a node-release technique and an application-mode methodology based on dynamic fracture toughness curves generated from measured data. Comparisons presented here indicate that the degree to which the dynamic solutions can be approximated by the static models is highly dependent on several factors, including the material dynamic fracture curves and the propensity for cleavage reinitiation of the arrested crack under PTS loading conditions. Additional work is required to develop and validate a satisfactory dynamic fracture toughness model applicable to post cleavage arrest conditions in an RPV.

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