PSI - Issue 50

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 50 (2023) 40–49

16th International Conference on Mechanics, Resource and Diagnostics of Materials and Structures (MRDMS 2022) Measurements of parameters of structures of C-C composites to ensure the computation of change in FV shape and aerodynamic characteristics V. G. Degtiar a , S. T. Kalashnikov b , B. I. Kapranov d , G. F. Kostin b , Yu. A. Mokin b , V. A. Tyumentsev c , V. I. Khlybov b , R. K. Shvaleva b, * a Makeyev SRC, 456320, Turgoyakskoye shosse, 1, Miass, Russian Federation Abstract The paper provides a designed under the supervision and with the participation of authors of the paper complex of methods of accounting for structural inhomogeneities of elements of a Thermal Protection System (TPS) made of C-C composites used to estimate ablated shapes of high-speed Flight Vehicles (FVs) and corresponding methods of measuring and processing of the needed structural parameters of C-C composites. During the mass ablation along a flight trajectory reinforcing elements and a graphitized matrix ablate differently, and there appears primary large-scale roughness on the surface. Moreover, pores, shells, and other fine-grained inhomogeneities outcrop forming the secondary finely divided roughness. Roughness impacts heat exchange, and summary equivalent roughness parameters are used to estimate FVs ablated shapes. A C-C composite graphitation degree that is defined with the X-ray diffraction study also influences an ablation rate. The density of materials is linearly related to their porosity, and for a number of currently in use and promising materials the density distributions were studied using computer tomography as well as the distribution of pores, shells, and other fine-grained inhomogeneities over volume of TPS elements was examined with electron microscopes. X-ray diffraction studies of the C-C composites were also carried out. Comparative computations of ablated shapes and aerodynamic characteristics of a model cylindrical FV with applied TPS elements of the examined C-C composites were performed with the use of obtained results of tomography, electron microscopic and X-ray diffraction studies. b SU FSC of MEG of UD of RAS, 456317, Ilmenskiy Zapovednik ter., Miass, Russian Federation c FSBEI of HE “CSU”, 454001, 129, Bratiev Kashirinykh st., Chelyabinsk, Russian Federation d FSAEI of HE NRTPU, 634050, 30, Lenina pr., Tomsk, Russian Federation

* Corresponding author. Tel.: +7-3513-28-69-40. E-mail address: src@makeyev.ru; rozashaleva@mail.ru

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the MRDMS 2022 organizers

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the MRDMS 2022 organizers 10.1016/j.prostr.2023.10.020