Stage | Description | Equation |
o-a | When a pull-out load , the fibre remain perfectly bonded to the matrix and the interface is kept in an elastic bond condition. |
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a-b | When , a part of the fibre is still fully bonded to the matrix while the remaining part is de-bonded. |
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b-c | Once interface de-bonding is completed at (b), the horizontal portion of the fibre must overcome kinetic friction as the hooked end of the fibre undergoes reverse bending. |
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c-d | Due to the cold work from both plastic hinges (PH1 and PH2), the pull-out load remains until the fibre pulled by an additional distance . |
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d-e | When PH1 has straightened, the fibre moves into the straight part of the channel. Then moving and straightening of PH2 results in a slight decrease in pull-out load. |
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e-f | At this stage, the load remains until the fibre is pulled by an additional distance . |
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f-g | Once both PH1 and PH2 are completely deformed and straightened, the load drops to (g) with no plastic hinges active. |
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g-h | At this stage, the pull-out load need only overcome kinetic frictional resistance as for a straight fibre. This phase prevails until the whole fibre is completely removed from the matrix at (h). |
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