A Study for Evaluating Local Damage to Reinforced Concrete Panels Subjected to Oblique Impact of Deformable Projectile

Many empirical formulas have been proposed for evaluating local damage to reinforced concrete structures caused by impacts of rigid projectiles. Most of these formulas have been derived based on impact tests perpendicular to the target structures. Up to now, few impact tests oblique to the target structures have been carried out. This study has been conducted with the purpose of proposing a new formula for evaluating the local damage caused by oblique impacts based on previous experimental and simulation results. In this paper, the results of simulation analyses for evaluating the local damage to reinforced concrete panels subjected to normal and oblique impacts by deformable projectile, by using the simulation method that the validity was confirmed through simulation analysis of past impact experimental results. Based on the results of these simulation analyses, the quantitative evaluation of reduction effects in the local damage caused by the difference of the impact angle is investigated.

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Evaluation of Local Damage to Reinforced Concrete Panels Subjected to Oblique Impact of Rigid and Soft Missiles

Volume 2: Plant Systems, Structures, Components, and Materials; Risk Assessments and Management ◽

10.1115/icone26-82615 ◽

2018 ◽

Author(s):

Akemi Nishida ◽

Minoru Nagai ◽

Haruji Tsubota ◽

Yinsheng Li

Keyword(s):

Reinforced Concrete ◽

Simulation Method ◽

Impact Angle ◽

Oblique Impact ◽

Local Damage ◽

Empirical Formulas ◽

Rc Structures ◽

Impact Tests ◽

Oblique Impacts ◽

The Impact

Many empirical formulas have been proposed for evaluating local damage to reinforced concrete (RC) structures caused by impacts of rigid missiles. Most of these formulas have been derived based on impact tests normal to the target structures. Up to now, few impact tests oblique to the target structures have been carried out. This study has been conducted with the purpose of proposing a new formula for evaluating the local damage caused by oblique impacts based on previous experimental and simulation results. In this paper, the results of simulation analyses for evaluating the local damage to a RC panel subjected to normal and oblique impacts by rigid and soft missiles, by using the simulation method that was validated using the results of previous impact experiments. Based on the results of these simulation analyses, the effects of the rigidity of the missile as well as the impact angle on the local damage to the target structures are clarified.

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A Study for Evaluating Local Damage to Reinforced Concrete Panels Subjected to Oblique Impact: Part 2 — Simulation Analysis of the Experimental Results of Local Damage Caused by Impact of Deformable Projectiles

Volume 2: Plant Systems, Structures, Components and Materials ◽

10.1115/icone25-66142 ◽

2017 ◽

Author(s):

Akemi Nishida ◽

Yoshimi Ohta ◽

Haruji Tsubota ◽

Yinsheng Li

Keyword(s):

Reinforced Concrete ◽

Simulation Analysis ◽

Impact Load ◽

Oblique Impact ◽

Local Damage ◽

Impact Tests ◽

Rigid Projectile ◽

Oblique Impacts ◽

Simulation Results ◽

The Impact

Many empirical formulae have been proposed for evaluating the local damage to reinforced concrete structures caused by rigid projectile impact. Most of these formulae are based on impact tests perpendicular to the target structures. To date, few impact tests oblique to the target structures have been conducted. In this study, we aim to obtain a new formula for evaluating the local damage caused by oblique impacts based on previous experimental and simulation results. We analyze and simulate the local damage owing to impact by deformable projectiles. The experimental and simulation results were in good agreement and confirmed the validity of the proposed analytical method. Furthermore, the internal energy of the deformable projectile absorbed upon impact was approximately 60% of the total energy. In comparison to a rigid projectile, it is possible to reduce the impact load and consequently the damage to the target.

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Local Damage to Reinforced Concrete Panels Subjected to Oblique Impact by Projectiles: Outline of Impact Test

Volume 1: Beyond Design Basis; Codes and Standards; Computational Fluid Dynamics (CFD); Decontamination and Decommissioning; Nuclear Fuel and Engineering; Nuclear Plant Engineering ◽

10.1115/icone2020-16843 ◽

2020 ◽

Author(s):

Akemi Nishida ◽

Zuoyi Kang ◽

Yukihiko Okuda ◽

Haruji Tsubota ◽

Yinsheng Li

Keyword(s):

Reinforced Concrete ◽

Impact Test ◽

Impact Angle ◽

Oblique Impact ◽

Local Damage ◽

Analysis Method ◽

Concrete Panels ◽

Oblique Impacts ◽

The Impact ◽

Specific Impact

Abstract Studies on the 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; thus, research on oblique impact is scarce. Due to this, we conducted research focusing on oblique impact to enable more realistic impact assessment of projectile collisions. To date, the validity of the analytical method has been confirmed by comparing the results with those of previous tests, and the local damage to RC panels that have collided with projectiles has been analytically investigated focusing on the impact angle. Therefore, this study aims to confirm the validity of the analysis method by conducting specific impact tests under various conditions, including the impact angle, by obtaining the relevant data. This paper outlines the test for the local damage to RC panels subjected to both normal and oblique impacts.

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A Study for Evaluating Local Damage to RC Panels Subjected to Oblique Impact: Part 1 — A Study for Evaluating Local Damage Caused by Oblique Impact of Rigid Projectiles

Volume 2: Plant Systems, Structures, Components and Materials ◽

10.1115/icone25-66175 ◽

2017 ◽

Author(s):

Yoshimi Ohta ◽

Akemi Nishida ◽

Haruji Tsubota ◽

Yinsheng Li

Keyword(s):

Reinforced Concrete ◽

Concrete Structures ◽

Oblique Impact ◽

Reinforced Concrete Structures ◽

Local Damage ◽

Normal Impact ◽

Impact Tests ◽

Oblique Impacts ◽

New Formula ◽

The Impact

Many empirical formulae have been proposed to evaluate the local damage to reinforced concrete structures caused by the impact of rigid projectiles. Most of these formulae have been derived based on impact tests perpendicular to the target structures. To date, few impact tests oblique to the target structures have been conducted. The purpose of this study is to propose a new formula for evaluating the local damage caused by oblique impacts based on experiments and simulations. The new formula is derived by modifying an empirical formulation for normal impact and the agreement with results of past oblique impact tests is discussed.

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Experimental and Analytical Investigation on Local Damage To Reinforced Concrete Panels Subjected to Projectile Impact Part 1: Penetration Damage Mode due to Normal Impact

10.1115/icone28-64521 ◽

2021 ◽

Author(s):

Zuoyi Kang ◽

Yukihiko Okuda ◽

Akemi Nishida ◽

Haruji Tsubota ◽

Yinsheng Li

Keyword(s):

Reinforced Concrete ◽

Analytical Investigation ◽

Oblique Impact ◽

Local Damage ◽

Damage Mode ◽

Target Structure ◽

Empirical Formulas ◽

Rc Structures ◽

Projectile Impact ◽

Impact Tests

Abstract Most empirical formulas have been proposed to quantitatively evaluate local damage to reinforced concrete (RC) structures caused by a rigid projectile impact. These formulas have been derived from impact tests performed to the target structure with a normal angle, while only a few impact tests involving soft projectile to the target structure have been studied. Recently, we conducted a series of impact tests to evaluate local damage to RC panels subjected to normal and oblique impact due to rigid and soft projectiles. The final goal of our study is to establish a new formula for evaluating local damage to RC structures caused by oblique impact based on experimental and analytical investigation. This paper summarizes the results of experimental and analytical investigation on penetration damage mode to RC panels subjected to normal projectile impact. Through the comparison between experimental and analytical results, the analytical method is validated.

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A Study for Evaluating Local Damage to Reinforced Concrete Panels Subjected to Oblique Impact: Part 3 — Simulation Analysis for Evaluating Perforation Phenomena Caused by Oblique Impact of Deformable Projectiles

Volume 2: Plant Systems, Structures, Components and Materials ◽

10.1115/icone25-66179 ◽

2017 ◽

Author(s):

Haruji Tsubota ◽

Yoshimi Ohta ◽

Akemi Nishida ◽

Yinsheng Li

Keyword(s):

Reinforced Concrete ◽

Simulation Analysis ◽

Oblique Impact ◽

Local Damage ◽

Normal Impact ◽

Projectile Velocity ◽

Response Characteristics ◽

Concrete Panels ◽

Transfer Processes ◽

New Formula

The purpose of this study is to propose a new formula for evaluating the local damage to reinforced concrete structures caused by oblique impact based on past experimental results and simulation results. In this paper, we present the results of simulation analyses for evaluating the perforation of concrete panels due to oblique impact by deformable projectiles. Various response characteristics and perforation mechanisms such as detailed perforation behavior, damage to reinforced concrete panels, rupture states of the deformable projectiles, reduction in projectile velocity, and residual velocity of the projectile after perforation, and energy transfer processes are clarified. Especially, it is found that the sliding energy consumed by friction occurring at the contact surface between a projectile and a reinforced concrete panel due to oblique impact is remarkably larger than that due to normal impact.

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