The importance and necessity of investigating the influence of a wide range of factors on behavior of composite materials and their real possibilities for operation conditions of rocket-space ...engineering structure elements are justified. Specifics of material structure and composition, technological processes of their production and design of complex elements, severe conditions of pre-operational tests, direct pre-flight preparation, and effect of complex thermal force factors in the course of controlled flights mean the necessity of experimental studies of the effects of such factors on current and residual physical-mechanical characteristics. For such tasks, the program development results, equipment, and methods of experimental studies of the effect of factors with different character on the integrity of real structures made of polymer composites for different loading modes and types of the stress state are presented. The object of the study is a shell model of a solid fuel rocket engine body made of polymer composite material. Analysis of test results of model shells made of IMS-65 E23 24K+Huntsman unidirectional carbon plastic made by annular winding (90°) under combined loading made it possible to determine the influence of design and technological factors on mechanical properties of these shells and their limit state. New data have been obtained concerning the behavior of such material under the complex action of force loading (compression–tension) and internal pressure (up to 10 MPa), taking anisotropy into account.
The paper presents the results of a computational assessment of the shape change of the WWER-1000 reactor core baffle using modern approaches to modeling the processes of radiation swelling, ...radiation creep, and subcritical damage of irradiated metal by the mechanism of ductile fracture. To simulate radiation effects, mathematical models are used that consider the influence of the stress state and accumulated irreversible deformation on the swelling and creep of austenitic steels exposed to neutron irradiation and elevated temperature. The increased volume concentration of ductile fracture pores in the irradiated metal is considered using the modified Huang equation and the proposed equation derived from Kachanov’s solution for a spherical cavity in an unbounded elastic-plastic medium. The determination of the stress-strain state of the WWER-1000 reactor cavity and the inner vessel shaft is based on solving a nonlinear boundary value problem of thermomechanics, which allows describing the kinetics of the coupled processes of elastic-plastic deformation, radiation swelling, radiation creep, contact interaction, and subcritical damage of irradiated metal depending on the accumulated dose of neutron irradiation. The computational analysis is based on a mixed finite element method scheme that provides a continuous approximation for both displacements and stresses and strains, which makes it possible to determine the shape change of the shielding with a high degree of accuracy. The calculation was performed in a two-dimensional formulation for the cross-section of the shielding with the maximum height of the damaging dose and irradiation temperature under the condition of generalized plane deformation. The calculation results were obtained using the median parameters of the temperature-dose dependence of free swelling of austenitic steel 08Kh18N10T. Based on the calculated data, the influence of radiation effects and metal damage according to the ductile fracture models on determining the shape change of the WWER-1000 reactor baffle under conditions of long-term operation was analyzed.
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