"Вестник МГСУ"

The article reveals comparative results of experimental model studies of the dynamical characteristics of containment shells used for their calculation and construction as well as actual calculation of dynamic characteristics and the results of actual full-scale investigations executed after 40 years of their operation. This comparison of present-day calculations and full-scale researches showed their agreement with the previous investigations performed on physical models of containment shells.The dynamic analysis of the facilities on the base of physical models were widely used in the 70's of the 20th century, when the computers were still in the initial level of development. The results of these model studies were used to justify the strength of critical structures, including nuclear power plants (NPPs), some of which have already worked for over 40 years. The current investigation gives the opportunity to compare the results of the previous model studies with the present calculations of NPP protective containments (shells) and the field studies results. The field investigations were carried out on the reactor containment of VVER-1000 reactor for the 1st unit of Kalinin NPP.1. Model studies of the dynamic characteristics on the physical model base. In order to provide dynamic model studies in the laboratory it is necessary to solve the following problems: 1) to fulfill certain similarity conditions, which provide unambiguous recalculation of the results to the full-scale structures; 2) to determine the scale of the model and its production material, which is related to the structure and characteristics of the vibration-testing machine (shaker), the transitional fixing devices for the model, special vibrators for dynamic loads, etc. The particular attention should be paid to the registration, processing and analysis of dynamic parameters, taking into account quality changes, which have recently occurred in the measurement technique. The model studies were carried out on a series of geometrically similar models of the protective containments fabricated under special technology of gypsum (1:100 scale) and plexiglas (1:200 scale). The models were mounted on a specially designed shaker. Harmonic oscillations with continuous frequency scanning were set up to the testers and resonant vibration frequency was recorded. Then the shell vibration mode was defined at these frequencies using small-sized mobile vibrometer. The frequencies of natural oscillations were recounted for correlation on similarity conditions.2. The study (investigation) of the dynamic characteristics of the protective containment on the base of mathematical model. The model is built in ANSYS calculation software complex and is structurally similar to the physical model, but without built elements and elastic foundation (i.e, the adopted conditions are similar to the physical model). The problem is solved in three-dimensional setting, all elements are made of three-dimensional elements (of solid type). The comparison of the experiment results on physical models and field studies is given in the Table.