Lazar V. Methods of evaluation of strength, crack growth vesistance of eccentric loaded iron-concrete structural elements

The thesis presents the main models and criteria of linear and non-linear fracture mechanics, and the results of investigations of strength, durability and stress-strain state of concrete and iron-concrete constructions. The distribution of strenses in a cross-section with lateral symmetriccracks, stress intensity factor Kic and damaging force in iron-concrete structures in axial tension have been established. The methods of evaluation of strength and durability on the basis of elastic-plastic fracture mechanics and mechanics of ferroconcrete constructions are shown. Design models are formulated and solutions of the problem of crack initiation and its subcritical growth of in non-stationary statement are proposed. The results of the analyses of the methods of fracture mechanics, expr-imental investigations and trecr trecr comparison with calculated ones are given.