Abstract
The work determines the stress intensity factor (SIF) at the crack tip in bending reinforced concrete beams. The problem has been solved in a three-dimensional formulation using special elements that take into account peculiarities of the stress field at the crack tip. Calculations have been carried out for beams of rectangular cross-section with pure bending to obtain analytical calculated dependences on variable factors. To obtain analytically calculated dependences on variable factors, a matrix of rational planning a multifactorial computer experiment has been compiled to determine the SIF and stress state parameters in bending rectangular reinforced concrete beams with a crack. Regression dependences for the SIF and the stress in the armature on the parameters of the beam and loading are obtained. The numerical calculation method is general and applies to beams of an arbitrary section under arbitrary loading. The obtained dependencies make it possible to evaluate the crack resistance of reinforced concrete beams according to the force criterion of fracture mechanics without the use of computer technology and expensive software complexes. In this paper, there is considered determining the SIF in bending reinforced concrete beams by the finite element method. The calculation results are presented in the form of the SIF regression dependences on the varied parameters.