The influence of internal defects (interlayer peeling) on the stress–strain state of a plane rectangular three-layer panel is studied numerically, by the finite-element method. The supporting outer layers of the three-layer package consist of polymer composite; various honeycomb fillers are considered. The results for polymer- and glass-based fillers are compared with one another and also with results for similar defect-free three-layer panels.
This paper reports the first part of a series of studies related to conceptual design of a fixed-wing UAV for Mars exploration. For a UAV intended for a single flight mission during the day, rational design parameters were determined and flight performance was estimated.
Acoustic emission diagnostics is applied to three zones of structural transformation in the wingbox: two are at the boundaries of the zone of stringer peeling; and the third is close to the edge of the technological window. Using the proposed methodology for dynamic monitoring of the variation in the contribution of the acoustic emission pulses to the lower, middle, and upper energy clusters, the kinetics of micro-, meso-, and macroscopic damage may be monitored during the loading of the wingbox, and the structural stability of the material in the region of the acoustic emission sources may be assessed.
In this paper, the physical nature of a stall of an aircraft along the sideslip angle is discussed. Measures to prevent a stall of an aircraft along the sideslip angle are described and justified, based on the results of the modeling and flight experiments.
