Investigating the effect of supports on reinforced concrete slab subjected to oblique missile impact

Kang, Z.; Okuda, Yukihiko; Nishida, Akemi; Tsubota, Haruji; Ito, Masaharu; Li, Y.

Proceedings of 31st International Conference on Nuclear Engineering (ICONE31) (Internet), 9 Pages, 2024/08

Most studies conducted till now on local damage of reinforced concrete (RC) slab structures subjected to missile impact are about normal impact, while few research related to oblique impact can be found. The objective of this study is to carry out impact tests under different impact conditions including oblique impacts, to confirm the different impact behaviors of the RC slab structure, to develop an analysis method by investigating the test results and analytical conditions, and to validate the analysis method through comparison with the test results. This study focuses on the effect of the stiffness of the supports for oblique impact on the reaction forces of RC slab. Until now, static loading tests were conducted to confirm the stiffnesses of the supporting parts that supported the RC specimen during oblique impact tests. Based on the obtained load-displacement relationships, and so on, the stiffnesses of the supporting parts are estimated.

Spectral evidence for Dirac spinons in a kagome lattice antiferromagnet

Zeng, Z.*; Zhou, C.*; Zhou, H.*; Han, L.*; Chi, R.*; Li, K.*; Kofu, Maiko; Nakajima, Kenji; Wei, Y.*; Zhang, W.*; et al.

Nature Physics, 20(7), p.1097 - 1102, 2024/07

https://doi.org/10.1038/s41567-024-02495-z

Validation of numerical analyses on scabbing of reinforced concrete panels subjected to projectile impact

Okuda, Yukihiko; Kang, Z.; Nishida, Akemi; Tsubota, Haruji; Li, Y.

Transactions of the 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT 27) (Internet), 10 Pages, 2024/03

The outer walls of nuclear facility buildings consist of reinforced concrete (RC) panels. When a projectile collides with a nuclear facility building, local damages such as penetration, scabbing, and perforation can occur in the RC panels. Numerical simulation using finite element analysis (FEA) is generally employed to assess these damage conditions. However, the impact analysis by FEA modelled with continuum elements is difficult to address phenomena such as scattering fragments of concrete because the elements deletion method for large deformation is used to prevent interruption of numerical calculations. Recently, a numerical method known as Smooth Particles Hydrodynamics (SPH), one of the particle methods, has been employed to address discontinuous phenomena. In this paper, we focus on the scabbing damages to RC panels and report on the findings obtained through the validation of the numerical analysis using the SPH method.

System of radiological protection; Towards a consistent framework on earth and in space

Rhm, W.*; Ban, Nobuhiko*; Chen, J.*; Li, C.*; Dobynde, M.*; Durante, M.*; El-Jaby, S.*; Komiyama, Tatsuto*; Ozasa, Kotaro*; Sato, Tatsuhiko; et al.

Journal of Medical Physics - Zeitschrift fr medizinische Physik -, 34(1), p.4 - 13, 2024/02

https://doi.org/10.1016/j.zemedi.2024.01.004

The International Commission on Radiological Protection (ICRP) provides independent recommendations on radiological protection for the public benefit. For more than 90 years, the ICRP System of Radiological Protection has been guiding the development and implementation of national and international standards and regulations on radiological protection. In 2019, ICRP established Task Group (TG) 115 to address a broader range of topics related to dose and risk assessment for radiological protection of astronauts. This paper gives an overview of the System of Radiological Protection and a brief summary of ICRP's work on radiological protection of astronauts.

PANDORA Project for the study of photonuclear reactions below

Tamii, Atsushi*; Pellegri, L.*; Sderstrm, P.-A.*; Allard, D.*; Goriely, S.*; Inakura, Tsunenori*; Khan, E.*; Kido, Eiji*; Kimura, Masaaki*; Litvinova, E.*; et al.

European Physical Journal A, 59(9), p.208_1 - 208_21, 2023/09

https://doi.org/10.1140/epja/s10050-023-01081-w

no abstracts in English

Intruder configurations in Ne at the transition into the island of inversion; Detailed structure study of Ne

Wang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.

Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08

https://doi.org/10.1016/j.physletb.2023.138038

Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.

Experimental study on scabbing limit of local damage to reinforced concrete panels subjected to oblique impact by projectile with semispherical nose

Okuda, Yukihiko; Kang, Z.; Nishida, Akemi; Tsubota, Haruji; Li, Y.

Mechanical Engineering Journal (Internet), 10(3), p.22-00370_1 - 22-00370_12, 2023/06

https://doi.org/10.1299/mej.22-00370

Many experimental studies have been reported on the impact resistance of reinforced concrete (RC) structures. However, most formulas were derived from impact tests based on normal impact to target structures using rigid projectiles that do not deform during impact. Therefore, this study develops a local damage evaluation method considering the rigidity of projectiles and oblique impacts that should be considered in realistic projectile impact phenomena. Specifically, we focused on scabbing, defined as the peeling off the back face of the target opposite the impact face, and conducted impact tests on RC panels to clarify the scabbing limit by changing the impact velocity in an oblique impact. The effects of the projectile rigidity and oblique impact on the scabbing limit were investigated based on the test results. This work presents the test conditions, equipment, results, and the scabbing limit on the local damage to RC panels subjected to oblique impacts.

Investigation on local damage of reinforced concrete panel impacted by hemispherical soft projectile

Kang, Z.; Okuda, Yukihiko; Nishida, Akemi; Tsubota, Haruji; Li, Y.

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 9 Pages, 2023/05

Most studies conducted till now on local damage of reinforced concrete (RC) slab structures subjected to projectile impact are about normal impact, while few research related to oblique impact can be found. The objective of this study is to carry out impact tests under different impact conditions including oblique impacts, to confirm the different impact behaviors of the RC slab structure, to develop an analysis method by investigating the test results and analytical conditions, and to validate the analysis method through comparison with the test results. This study focuses on the scabbing damage which is one of the local damage modes of RC slab. Based on oblique impact test results due to soft projectile with hemispherical nose shape, we investigate the relationship between the criterion related to the concrete fracture and the occurrence of scabbing damage.

First observation of the decay of the 13/2 isomer in Hg and (2) systematics of neutron transitions across the nuclear chart

Huang, H.*; Zhang, W. Q.*; Andreyev, A. N.; Liu, Z.*; Seweryniak, D.*; Li, Z. H.*; Guo, C. Y.*; Barzakh, A. E.*; Van Duppen, P.*; Andel, B.*; et al.

Physics Letters B, 833, p.137345_1 - 137345_8, 2022/10

https://doi.org/10.1016/j.physletb.2022.137345

Experimental study on local damage to reinforced concrete panels subjected to oblique impact by projectiles; Analysis of experimental results

Kang, Z.; Okuda, Yukihiko; Nishida, Akemi; Tsubota, Haruji; Li, Y.

Transactions of the 26th International Conference on Structural Mechanics in Reactor Technology (SMiRT-26) (Internet), 8 Pages, 2022/07

So far, studies on local damage to reinforced concrete (RC) panels subjected to projectile impact have mainly focused on collisions that occur at an angle normal to the structure, while research on oblique impact is scarce. In this research, we conducted a series of impact tests to confirm validity of the analytical method based on the investigation on local damage behavior of RC panel due to projectile impact under various impact conditions covering impact angles, projectile types (rigid and soft) and RC panel's thickness. In part 2, we concentrate on the investigation to the penetration damage and scabbing damage of RC panels subjected to normal and oblique impact by rigid and soft projectiles. Based on the analysis of experimental results, the obtained knowledge will be presented.