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Information × Registration Number 0221U105197, 0116U006284 , R & D reports Title Development of experiment-calculated methods of an assessment of deflected mode and durability of composite elements of designs of aerospace equipment popup.stage_title Head Kucher Mykola KYRYLOVYCH, Доктор технічних наук Registration Date 14-06-2021 Organization G.S. Pisarenko Institute for Problems of Strength of the National Academy of Sciences of Ukraine popup.description2  An analytical and experimental study of the bearing capacity and strength of uniaxial composite materials at high temperatures (ablation), which are made by continuous winding. A new method of stress and strain analysis, as well as estimation of critical stress in uniaxial composite operating at high temperatures is proposed. The solving equations describing the change in the density of the composite matrix and carbon fibers in the oxidizing medium at high temperatures are concretized, assuming that the material phases exist in each cell of the composite at any time, and that only the volume phase ratios change during heating. It is shown that the density of the composite matrix and fibers depends on both the heating rate and the temperature. The exact dependences of density on temperature (in the range of 20… 300 ° C) for fixed heating rates in the form of an integral exponential function and elementary functions are obtained. Accurate expressions for thermal deformation of the composite along the fibers and in the transverse direction are obtained, which allows to calculate the coefficients of thermal expansion of the composites in the main directions. Also within the model of an orthotropic body all elastic characteristics of a unidirectional composite depending on temperature at a fixed heating rate are completely defined. The results of tests of an orthotropic cylinder under axisymmetric deformation under conditions of quasi-static heating are presented, which showed a good correspondence between the effective parameters of the elasticity of the composite in the experiment and those predicted by our model. It is noted that the assessment of critical stress using the criteria of maximum stress and maximum deformation may be incorrect. Possibilities of calculations and at use of commercial packages of application programs are considered and possible errors at forecasting of destruction of the products made on technology of continuous winding are analyzed. Product Description popup.authors popup.nrat_date 2021-06-14 Close