COMPUTER-IMPLEMENTED METHOD FOR ESTIMATING THE SERVICE LIFE OF A CRACKED PART AND A SYSTEM FOR ESTIMATING THE SERVICE LIFE OF A PART

摘要

FIELD: mechanical parts.;SUBSTANCE: invention relates to the analysis of crack propagation in mechanical parts. The essence - a digital model of the surface of a part that has a crack and is subjected to cyclic loads during operation is preliminary obtained. Estimation of the stress intensity factor in the part is carried out on the basis of the specified digital model of the part, within the framework of modeling the propagation of a fatigue crack, while performing the following steps: (Е2): from the digital model of the analyzed part (20), a set of simulated values are obtained at different points of the analyzed part (20), while the specified set of simulated values includes, for different simulated steps of propagation of a three-dimensional crack, which is detected on the specified digital model of the part, a set of simulated values the stress intensity factor at the corresponding points, the position of these points and the data related to the cracked surface of the specified crack, (Е3): for each propagation step and for the specified set of modeled values for the corresponding step, the transformed effective value of the total equivalent stress intensity factor corresponding to the effective value of the stress intensity factor of a flat crack with a straight front is determined, and the transformed length of the considered equivalent crack is determined, wherein these transformed values are determined by equalizing the energy dissipated in the three-dimensional crack of the specified digital model and the energy dissipated in the crack of the standard model of a flat crack with a straight front, while the energy values themselves are determined in accordance with the stress intensity factors, (Е4): the transformed effective values of the total equivalent stress intensity factor are interpolated between two successive transformed crack lengths; and (Е5): the obtained interpolated transformed effective values of the total equivalent stress intensity factor are stored in memory together with the corresponding crack lengths; and estimating the service life of the part using the specified stored interpolated transformed effective values of the total equivalent stress intensity factor with the corresponding crack lengths. The system for evaluating the service life of a part contains a data processing unit (12) containing means (14) of calculation and a memory (16), while the said data processing unit is designed to implement a method for assessing the service life of a cracked part subjected to cyclic loads during operation and for which there is a digital model of the part’s surface. ;EFFECT: capability to reliably estimate the service life. ;8 cl, 10 dwg