Macrocrack crack, fracture mechanics

As mentioned previously, cracks start in the brittle fracture mechanism by the counter process, which includes the birth and development of cracks in the area of prefailure and its association with the macrocrack. Further development of the macrocrack, [13] further development of the microcrack is, perhaps, due to two alternative mechanisms. 

Thus, the development of brittle fracture does not occur on a counter mechanism (as opposed to the start of brittle fracture), and is directly related to the growth of the main crack (macrocrack). By this means the possibility exists to use the concept of fracture mechanics, which reduces to the solution of the left-hand side of the formulas (3.9) and (3.10) (the parameters K, G, depending on the mode of loading design), and the right—the critical values that characterize the material s properties. 

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