Explore the vast range of titles available.

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.

A bstract The inclusion of an additional U(1) gauge L μ − L τ symmetry would release the tension between the measured and the predicted value of the anomalous muon magnetic moment: this paradigm assumes the existence of a new, light Z ′ vector boson, with dominant coupling to μ and τ leptons and interacting with electrons via a loop mechanism. The L μ − L τ model can also explain the Dark Matter relic abundance, by assuming that the Z ′ boson acts as a “portal” to a new Dark Sector of particles in Nature, not charged under known interactions. In this work we present the results of the Z ′ search performed by the NA64- e experiment at CERN SPS, that collected ~ 9 × 10 11 100 GeV electrons impinging on an active thick target. Despite the suppressed Z ′ production yield with an electron beam, NA64- e provides the first accelerator-based results excluding the g − 2 preferred band of the Z ′ parameter space in the 1 keV < m Z ′ ≲ 2 MeV range, in complementarity with the limits recently obtained by the NA64- μ experiment with a muon beam.

A universal GDS-16 data acquisition and control system based on Quantum X MX840 measuring amplifiers and Catman Easy software is described. The system provides multichannel measurements of strains, displacements, pressures, and temperatures, data processing, visualization, and accumulation, which permits strength and thermomechanical tests of materials and structure elements to be performed.

The paper considers the problem of creating and operating products of reusable space-rocket hardware, in particular with respect to ensuring the integrity of structural elements and safe return to Earth under aerodynamic heating conditions. This problem has two aspects, which differ in specificity of the approaches to designing the elements of space shuttle systems (SSS). The first aspect is associated with ensuring the reliable functioning of the most thermally stressed elements of the re-entry glider, which are structures with large angles of attack, such as fuselage nose and leading edge, wing loading edge, elevators and air intake edges. The second aspect mainly concerns ensuring the allowable temperature level of the spacecraft pressure shell on all flight path segments, especially during re-entry in the Earth’s atmosphere. In view of this, one of the main goals in creating SSSs is to develop a reliable heat shield having acceptable size and weight parameters, and cost. The successful solution of these problems is determined in many respects by the optimal choice of appropriate classes of materials: special high-temperature alloys, structural ceramics, highmelting-point metallic and polymeric composite materials. For the modern structures of SSSs, the use of structural metallic materials is worth-while in many respects. Rig test procedures are proposed. A complex of gas-dynamic test rigs was used as the basic equipment, whose fundamental design features and methodological solutions ensure the complete rig test cycle for the solution of problems in both directions. The methodological basis of rig tests is a set of specialized procedures for the simulation of thermally stressed states of the material and the intesity of the external action of the environment, which provide the equivalence of material damage processes and the limit state of the structural element under investigation under model and full-scale conditions. The fundamental basis of these approaches is the classical similarity and dimensional theories, the main postulates of which have been transformed and adapted to the problems of the study of the strength of materials and damageability of structural elements under thermal cyclic loading in corrosive environments. The developed procedures and experimental means allowed the modeling of aerodynamic heating processes of the structural elements of space shuttles. It has been shown that the implemented methods enable the evaluation of functional characteristics, determination of a set of properties and refinement of the technology for the formation of structural elements of aerospace vehicles operating under the conditions of aerodynamic heating to extremely high temperatures.

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.

Studies of surface layer material degradation of the most loaded elements of gas turbine engine structural components revealed the essential changes in the structure and elemental composition of this layer in the thermal fatigue crack initiation zones, as well as along the propagating crack lips. The intensity of the observed changes implies the necessity of their account in the stress-strain state calculations and residual life estimations of high-temperature structural components of gas turbine engines.

A PMX-TEST multifunctional data acquisition and control system rigging the beds and units for strength tests of models and structure elements from composite materials is described. The system provides the multichannel measurement of strains, pressures, and temperatures. The corresponding PMX-TEST-Monitor software ensures digital and graphical representation of experimental data, their accumulation and storage for further processing.

In order to create, ensure the functioning and effective use of the megascience-project, it is necessary to have a holistic view of the concept of \"megascience\", the basic processes and constraints that accompany this activity and the project life cycle. For this purpose an analysis of the life cycles of various megaprojects was carried out, and as a result of the analysis, the main stages characteristic of all the projects reviewed were identified. Also considered are approaches to the implementation of these stages and a list of possible restrictions and risks is defined. Based on the data obtained, a model for creating a megaproject on the territory of the Russian Federation is proposed, in particular, it is planned to apply the obtained result in the process of creating the International Center for Neutron Research based on the PIK high-flux research reactor. The reported study was funded by RFBR according to the research project № 18-29-15015.

The developed and currently manufactured debuncher for the injector part of the accelerator facility NICA is designed to reduce the energy spread by a factor of up to ten in the ion bunches with Z/A=(0.33-1) at the output of the LU-20 linac. The debuncher includes a Split-Ring cavity, a vacuum system, a solid-state RF amplifier and an RF controller. The main design parameters are described.

The Transverse Deflecting System XFEL TDS System INJ has been built as the part of the European X-ray Free Electron Laser for longitudinal bunch profile and slice emittance measurements. The 0.7 long Transverse Deflecting Structure (TDS), as the part of the system, has been built on base of the disk-loaded structure with hybrid EH-wave, operating frequency 2997.2 MHz and pulse input RF power up to 3 MW. The structure has been built, tuned and installed in the XFEL Injector beam line. All design parameters have been got at low RF power level. Electron beam has been passed through the whole Injector including TDS.