Fibre Break Failure Processes in Unidirectional Composites. Part 2: Failure and Critical Damage State Induced by Sustained Tensile Loading

2014 ◽  
Vol 22 (2) ◽  
pp. 141-155 ◽  
Author(s):  
A. Thionnet ◽  
H. Y. Chou ◽  
A. Bunsell
Keyword(s):  
Tensile Loading ◽  
Damage State ◽  
Unidirectional Composites ◽  
Fibre Break ◽  
Critical Damage

scholarly journals Fibre break failure processes in unidirectional composites: evaluation of critical damage states

2016 ◽  
Vol 374 (2071) ◽  
pp. 20150270 ◽  
Author(s):  
A. Thionnet ◽  
A. R. Bunsell
Keyword(s):  
Structural Integrity ◽  
Critical Density ◽  
Tensile Loading ◽  
Unidirectional Composites ◽  
Fibre Breakage ◽  
Fibre Break ◽  
Sustained Loading ◽  
Damage States ◽  
Large Clusters ◽  
Kinetics Of

Earlier work which successfully modelled the kinetics of fibre breakage in unidirectional composites under monotonic tensile loading has been extended to quantify the kinetics of fibre failure during both monotonic and sustained tensile loading. In both cases, failure was seen to occur when a critical density of large clusters (more than 16 fibres are broken within the representative volume element) of fibre breaks developed. However, in monotonic loading failure occurred very quickly after the first development of these large clusters, whereas under sustained loading the composite could accommodate greater levels of large clusters because of the lower applied load. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’.

scholarly journals An Analytical Model to Predict Fracture of Off-Axis Unidirectional Composites

2002 ◽  
Vol 11 (5) ◽  
pp. 096369350201100
Author(s):  
J. Petermann ◽  
A. Plumtree ◽  
K. Schulte
Keyword(s):  
Analytical Model ◽  
Stress Component ◽  
Tensile Loading ◽  
Uniaxial Tensile ◽  
Homogeneous Material ◽  
Stress Distributions ◽  
Material Behaviour ◽  
Unidirectional Composites ◽  
Failure Initiation ◽  
Good Agreement

An analytical model based on isotropic homogeneous material behaviour is proposed to predict fracture in unidirectional composites under general loading. The model calculates the internal stress distribution corresponding to the applied load. In conjunction with the respective strength values, the model is capable of assessing the dominant stress component for failure initiation. For uniaxial tensile loading a comparison of calculated analytical stress distributions reasonably agrees with results from FE-analysis. A comparison of the analytical predictions with fractographic results for different off-axis angles provides good agreement.

Sem Examinations of Glass Knives

1970 ◽  
Vol 28 ◽  
pp. 282-283
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Tensile Loading ◽  
Resultant Force ◽  
Stress Concentrations ◽  
Edge Chipping ◽  
Surface Flaws ◽  
Edge Defects ◽  
Microscopic Surface

There are two types of edge defects common to glass knives as typically prepared for microtomy purposes: 1) striations and 2) edge chipping. The former is a function of the free breaking process while edge chipping results from usage or bumping of the edge. Because glass has no well defined planes in its structure, it should be highly resistant to plastic deformation of any sort, including tensile loading. In practice, prevention of microscopic surface flaws is impossible. The surface flaws produce stress concentrations so that tensile strengths in glass are typically 10-20 kpsi and vary only slightly with composition. If glass can be kept in compression, wherein failure is literally unknown (1), it will remain intact for long periods of time. Forces acting on the tool in microtomy produce a resultant force that acts to keep the edge in compression.

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