Approaches to studying the processes of appearance and development of stress-strain state depending on vibration loading modes of a structure element

The purpose of the research is to determine the permissible and limiting modes of vibration loading of a plate imitating an aircraft skin element and made of D16a alloy, followed by the assembly and commissioning of an experimental research stand for the appearance and development of the stress-strain state of this plate. The cyclic effect of broad-band random vibration simulates operational operating conditions that cause the loss of elastic properties of the material and its aging, accompanied by a decrease in the angle of inclination of the hodograph formed by a three-dimensional vector of vibration accelerations relative to the horizontal plane. Methods. Mathematical modeling methods were used to determine the permissible and limiting modes of vibration loading of the plate. The study of the aging processes of the plate material, accompanied by loss of elastic properties, is performed by an equivalent cyclic method, each cycle of which contains two phases: the first is the phase of vibration loading of the plate, the second is the phase of visual and X-ray laboratory control, during which internal defects in the plate structures must be detected (if any) or their development recorded. The detection of such defects indicates a likely imminent violation of the integrity of the plate imitating the aircraft skin element. Results. The values of the permissible and maximum load on the plate imitating the aircraft skin element are determined. The assembly and commissioning of a stand for experimental studies of stress-strain state processes has been carried out, and the hypothesis that the hodograph formed by a three-dimensional vector of vibration accelerations has an initial angle of inclination relative to the horizontal plane of 45° has been confirmed. However, there has not yet been a noticeable aging effect in which the specified angle changes. Conclusion. Changing the angle of inclination of the hodograph formed by a three-dimensional vector of vibration accelerations makes it possible to judge the degree of wear of the materialwith the possibility of further forecasting the remaining life of the material. It is proposed to continue the research in terms of collecting an array of experimental data.