Impact of High Velocity Objects Into Concrete Structures: Methodology and Application

2003 ◽  
Author(s):  
R. J. James ◽  
L. Zhang ◽  
J. Y. R. Rashid
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
High Velocity ◽  
Nuclear Power ◽  
Power Plants ◽  
Highway Bridges ◽  
Concrete Walls ◽  
Explicit Finite Element ◽  
Reinforced Concrete Walls ◽  
Close Proximity

Lifeline safety structures, such as, for example, concrete dams, nuclear power plants, and highway bridges, are designed to high levels of safety using traditionally conservative methods. Events of recent years, however, have raised public concerns about the degree of vulnerability of these structures to deliberate attacks involving large-airplane crash or close-proximity blast loading. This paper presents recent development in the state of the art of finite-element-based constitutive modeling and computational methodology of reinforced concrete with emphasis on severe damage modeling and failure evaluation. Verification and validation of the developed methodology is illustrated using high-velocity impact tests conducted in the U.S. and Japan. This involves explicit finite element computations for high velocity rigid missiles impacting reinforced concrete walls. Application of the methodology to nuclear fuel facilities is discussed.

scholarly journals Comparing Performance of Cross-Laminated Timber and Reinforced Concrete Walls

2021 ◽  
Vol 26 (3) ◽  
pp. 28-43
Author(s):  
A. Bahrami ◽  
O. Nexén ◽  
J. Jonsson
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Cost Effective ◽  
Concrete Walls ◽  
Cross Laminated Timber ◽  
Analysis And Design ◽  
Lower Weight ◽  
Reinforced Concrete Walls ◽  
Design Software ◽  
The City

Abstract The purpose of this research is to specify the differences between the performance of cross-laminated timber (CLT) and reinforced concrete (RC) walls. The study is done by using the finite element structural analysis and design software, StruSoft FEM-Design, in order to model, analyse and design a reference building located in the city of Gävle in Sweden. The building is firstly modelled, analysed and designed using RC walls and then the RC walls are replaced with CLT walls. In both buildings, other load-bearing elements such as slabs, beams and columns are made of RC while the roof beams are made of glulam. It is found that employing RC has advantages, especially regarding thickness. The results show that the CLT walls require larger dimensions than their RC counterparts. Meanwhile, it is demonstrated that the slabs, beams and columns made of RC in the building having the CLT walls require more reinforcement or larger thickness than the case of walls made of RC. Moreover, the total weight of the building having the CLT walls is 74% of the building having the RC walls. The lower weight of the building having the CLT walls has great advantages such as having lighter foundation and being cost-effective and also beneficial for the environment.

scholarly journals Study on Radiation Shielding Performance of Reinforced Concrete Wall After the Earthquake

2010 ◽  
Vol 5 (4) ◽  
pp. 361-368
Author(s):  
Keiji Sekine ◽  
◽  
Yoshinari Munakata ◽  
Osamu Kontani ◽  
Koji Oishi ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Nuclear Power ◽  
Radiation Shielding ◽  
Crack Model ◽  
Concrete Wall ◽  
Concrete Walls ◽  
Reinforced Concrete Walls ◽  
Earthquake Resistant ◽  
Reinforced Concrete Wall ◽  
Large Earthquakes

The structure in which radioactive substances are stored and handled must be earthquake resistant. We will be confirming radioactive shielding performance of reinforced concrete walls when cracks occur due to large earthquakes. In this study, we performed horizontal loading experiments to evaluate shielding performance of earthquake resisting walls and constructed a safety crack model. Next, the shielding calculation was done by using the crack model, and the shielding performance of the earthquake resisting wall was evaluated. As a result, if the structure is designed according to the standards outline for nuclear power related facility, and an earthquake causes cracks in an earthquake resisting wall, it was shown that if the thickness of the earthquake resisting wall was less than 80 cm, the decrease in shielding performance was very small, and that the radiation exposure on the general public and the employee was negligible.

Impact of Aircraft Engines Into Reinforced Concrete Walls

2002 ◽  
Author(s):  
Darrell Lawver ◽  
Darren Tennant ◽  
John Mould ◽  
Howard Levine
Keyword(s):  
Reinforced Concrete ◽  
Constitutive Model ◽  
Power Plants ◽  
Concrete Walls ◽  
Reinforced Concrete Walls ◽  
Rate Dependent ◽  
Hexahedral Elements ◽  
Failure Models ◽  
Engine Components ◽  
The Impact

Major components of storage facilities and nuclear power plants are designed using reinforced concrete walls. Accidental or intentional impact of these structures by aircraft is a concern. The potential for penetration of these facilities by the aircraft or its components and the subsequent damage to the contents and release of toxic substances is a major concern. This paper focuses on analyzing the impact of jet engines into heavily reinforced concrete walls. These engines are among the stiffest and most massive components of an aircraft and the most likely to seriously damage and penetrate the reinforced concrete. We model both the engine and the reinforced concrete deformations using failure models for reinforced concrete and metals. Unlike many projectile impact problems, the impacting engine cannot be considered to be rigid. A large amount of energy is consumed in the plastic deformation and fracture of the engine components. The reinforced concrete is modeled using hexahedral elements for the concrete and beam elements for the rebar reinforcement. An advanced three invariant viscoplastic softening cap constitutive model describes the ductile and brittle rate-dependent characteristics of concrete. The rebar is modeled using a rate dependent, strain hardening von Mises formulation with failure controlled by fracture energy dissipation. A similar constitutive model is employed for the shell elements used to represent the engine components. These failure models are included in the FLEX large deformation finite element code which uses an explicit, central difference solution procedure with subcycling to solve the equations of motion. Element erosion using different criteria for concrete and metals is used to remove severely distorted and failed elements. Procedures used to mitigate the deleterious and unrealistic effects of hourglass control and viscoplasticity in the softening and failure regimes are discussed. The results from the computations are compared with experimental data generated by impacting a TF-30 engine into a two foot thick concrete wall.

State-of-the-art in nonlinear finite element modeling of isolated planar reinforced concrete walls

2019 ◽  
Vol 194 ◽  
pp. 46-65 ◽  
Author(s):  
Kristijan Kolozvari ◽  
Lauren Biscombe ◽  
Farhad Dashti ◽  
Rajesh P. Dhakal ◽  
Aysegul Gogus ◽  
...  
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Modeling ◽  
State Of The Art ◽  
Nonlinear Finite Element ◽  
Concrete Walls ◽  
Element Modeling ◽  
Reinforced Concrete Walls

scholarly journals Numerical analysis of construction of drainage system for precipitation waters

2013 ◽  
Vol 12 (3) ◽  
pp. 091-096
Author(s):  
Piotr Gąska
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Quantitative Analysis ◽  
Numerical Model ◽  
Lateral Pressure ◽  
Drainage System ◽  
Vertical Direction ◽  
Concrete Walls ◽  
Reinforced Concrete Walls

Progressive implements which make possible advanced geotechnical analysis, induced the author to verify previously accepted engineering solutions of construction of rain waters drainage system with the use of reinforced concrete walls and horizontal geogrids. The quantitative analysis of stress distribution in ground medium around the drainage system was performed in numerical model with the use of finite element method . This analysis confirmed previous – intuitive and qualitative - assumptions of the technical design. The application of reinforced concrete walls, transmission of ground lateral pressure to the soil below and the above drainage system, result in twofold reduction of horizontal components of ground stresses in area between reinforced walls and the drainage. The usage of two layers of geogrid over the drainage system  made possible strain relief of this system (in the middle, the most sensitive zone) in vertical direction of about 75%.

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