Dynamic responses of a hinged-hinged Timoshenko beam with or without a damage subject to blast loading

This paper, taking the clamped boundary condition as an example, develops Su and Ma's fundamental solutions of the dynamic responses of a Timoshenko beam subjected to impact load. Based on that, a further extension regarding the general moving load case is also established. Kelvin–Voigt damping, whether proportionally or nonproportionally damped, is incorporated into the model, making it more comprehensive than the model of Su and Ma. Numerical inverse Laplace transformation is introduced to obtain the time-domain solution, where Durbin's formula and the corresponding convergence criteria are utilized in numerical experiments. Further, the real modal superposition method is applied at an analytical level to validate the numerical results by applying a proportionally damped condition. Total comparisons are made between the methods by sufficient case studies. The dynamic responses with and without damping effect are computed with wider slenderness to verify the correctness and effectiveness of the numerical results. Furthermore, parametric studies regarding the damping coefficients are performed to explore the nonproportional damping effect. The results show that the structural damping has significant influences on the dynamic behaviors and is especially stronger at small slender ratios. As the damping decreases the inherent frequencies and excites the low-frequency modal components more actively, a resonant phenomenon appears in high slenderness case when the beam experiences a low-speed moving load. Additionally, the computations in the moving load case indicate that the algorithm convergence is preferable when the number of grids exceeds 1000.

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Dynamic responses and energy absorption of hollow sphere structure subjected to blast loading

Materials & Design ◽

10.1016/j.matdes.2019.107920 ◽

2019 ◽

Vol 181 ◽

pp. 107920 ◽

Cited By ~ 3

Author(s):

Fan Tang ◽

Yanlong Sun ◽

Zerong Guo ◽

Wensu Chen ◽

Mengqi Yuan

Keyword(s):

Energy Absorption ◽

Hollow Sphere ◽

Blast Loading ◽

Dynamic Responses

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Dynamic damage assessment of float glass under blast loading

Advances in Structural Engineering ◽

10.1177/1369433219845691 ◽

2019 ◽

Vol 22 (11) ◽

pp. 2517-2529

Author(s):

Xiao-Qing Zhou ◽

Ming-Yu Wang ◽

Li-Xiao Li

Keyword(s):

Damage Assessment ◽

High Speed ◽

Blast Loading ◽

Material Model ◽

The United States ◽

Float Glass ◽

Dynamic Responses ◽

Kinematic Equation ◽

Finite Element Software ◽

Dynamic Damage

Architectural glass, especially the float glass, is a fragile part of a building. The architectural glass becomes a large amount of high-speed flying debris under bomb attacks and accidental explosions, thereby causing serious threat to residents. This study investigates the dynamic responses of a normal float glass subjected to blast loading using the explicit dynamic finite element software LS-DYNA. A JH-2 material model, which considers the strain rate effect and damage accumulation, is adopted for the float glass. A preliminary study shows that the present numerical model combined with reasonable material parameters can simulate the failure mode of the glass and the ejection velocity of glass fragments after failure. The verified model is then used to investigate the dynamic damage responses of the float glass under different loading cases. The damage assessment criterion of float glass is established on the basis of the glazing protection levels defined by the General Services Administration of the United States. Comprehensive simulations are conducted on different amounts of explosive and standoff distances. The degrees of glass damage under different loading cases are determined by combining the projection velocity of glass fragments after failure with a kinematic equation. Finally, the damage assessment diagram of float glass under different amounts of explosive is presented and compared with those in FEMA 426.

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Dynamic responses of concrete piers under close-in blast loading

International Journal of Damage Mechanics ◽

10.1177/1056789516653245 ◽

2016 ◽

Vol 25 (8) ◽

pp. 1235-1254 ◽

Cited By ~ 8

Author(s):

Zhi-Jian Hu ◽

Liang Wu ◽

Yi-Feng Zhang ◽

LZ Sun

Keyword(s):

Blast Loading ◽

Dynamic Responses

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Research on Dynamic Response of Slopes With Weak Interlayers Under Mining Blasting Vibration

Frontiers in Energy Research ◽

10.3389/fenrg.2021.812492 ◽

2022 ◽

Vol 9 ◽

Author(s):

Xiaochao Zhang ◽

Qingwen Yang ◽

Xiangjun Pei ◽

Ruifeng Du

Keyword(s):

Dynamic Response ◽

Internal Structure ◽

Explosive Charge ◽

Blast Loading ◽

Dynamic Responses ◽

Internal Dynamic ◽

Explosive Energy ◽

Wide Range ◽

Blasting Excavation ◽

Weak Interlayer

As blasting technology starts to be used in a wide range of areas, blast loading has led to an increasing number of geological disasters such as slope deformation, collapses, and soil slippage. Slopes with weak interlayers are more likely to be deformed and damaged under the influence of blast loading. It is of great importance to study the evolution for the deformation of slopes with weak interlayers during blasting excavation. This study constructed a slope model with a weak interlayer to investigate the influence of different factors of blasting, including explosive charge, blast radius, blast origin, and multi-hole blasting, on the internal dynamic response. The deformation mechanism of slopes with weak interlayers under the influence of blast loading was analyzed. Test results show that each layer of the model had a different displacement response (uncoordinated dynamic response) to blasting with various factors. Explosive energy and the pattern of dynamic response of each layer varied depending on different settings of blasting factors such as explosive charge, blast radius, blast origin, and detonation initiation method. When the explosive energy produced under the influence of various factors was small, the change in the uncoordinated dynamic response between layers was significant, and the change gradually became less significant as the explosive energy increased. Therefore, this study has proposed the concept of critical explosive energy, and it is speculated that when the explosive energy produced with various factors is less than critical explosive energy, the dynamic response is mainly affected by the internal structure of the slope (property difference induced geologic layers). In other words, the uncoordinated motion of material’s particles in each layer is caused by different limitations and the degree of movement of the particles, which leads to the uncoordinated dynamic response and uncoordinated deformation of each layer. If the explosive energy is greater than the critical value, the dynamic response of each layer is mainly affected by the explosive energy. The differences in the internal structure of the slope are negligible, and the incoordination of dynamic responses between layers gradually weakens and tends to synchronize.

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Numerical Investigation of the Dynamic Responses and Damage of Linings Subjected to Violent Gas Explosions inside Highway Tunnels

Shock and Vibration ◽

10.1155/2018/2792043 ◽

2018 ◽

Vol 2018 ◽

pp. 1-20 ◽

Cited By ~ 2

Author(s):

Zhipeng Li ◽

Shunchuan Wu ◽

Ziqiao Cheng ◽

Yibo Jiang

Keyword(s):

Numerical Simulation ◽

Blast Loading ◽

Damage Mechanism ◽

Relevant Information ◽

Dynamic Responses ◽

Economic Losses ◽

Future Research ◽

Gas Explosion ◽

Empirical Formulas ◽

Fully Coupled

The linings of structures suffer severe damage when subjected to internal explosions, which cause numerous casualties and incalculable economic losses. In this paper, a violent gas explosion that occurred inside a highway tunnel in the city of Chengdu, China, is studied through numerical simulations. The evaluated energy of the gas explosion was equivalent to 2428.9 kg of TNT. A fully coupled numerical model consisting of five parts is established with dimensions consistent with the real prototype dimensions and by considering fluid-structure interaction (FSI) effects. Then, a detailed modelling process is presented and validated through a comparison with empirical formulas. This paper investigates the strength and propagation characteristics of a blast shock wave inside the tunnel, and both the effective stresses and dynamic responses of the lining are analysed under the blast impact loading. The damage mechanism is studied, and the evolution of the lining damage is reproduced, the results of which show good agreement with the actual conditions. Moreover, in terms of the responses and damage of the lining, the fully coupled blast loading model has obvious advantages in comparison with the simplified blast loading model. Furthermore, the damage assessment of the lining conducted using the single degree of freedom (SDOF) method agrees well with the results of the numerical simulation and site investigations. The comprehensive numerical simulation technique used in the present paper and its results could represent valuable references for future research on violent explosions within tunnels or very large underground structures and provide relevant information for the blast-resistant design of such structures.

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The Dynamic Responses of RC Columns Subjected to Blast Loading

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.784 ◽

2011 ◽

Vol 105-107 ◽

pp. 784-790

Author(s):

Zhi Ping Kuang ◽

Lei Xie ◽

Qiu Hua Yang ◽

Yi Ling Dong

Keyword(s):

Progressive Collapse ◽

Blast Loading ◽

Dynamic Responses ◽

Blast Loads ◽

Rc Columns ◽

Dangerous Situation ◽

Blast Resistant Design

The blast-resistant performance of columns which are the most important component in the whole structure is a crucial factor which influences the safety of the structures subjected to the blast loads. Studying dynamic responses of RC columns under the blast loading and improving the blast-resistant performance can prevent the structure from progressive collapse due to the damage of the columns in the blast loading, and give people more time to escape from the building in a dangerous situation. Then the same parameters are used to analyze the dynamic responses of RC columns under three typical blast loads. Conclusion can be used for structure blast-resistant design.

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Calculation of Dynamic Parameters of Elastic Thin Plates under Blast Loading

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.2749 ◽

2007 ◽

Vol 353-358 ◽

pp. 2749-2752

Author(s):

Yue Sheng Fu ◽

Qing Ming Zhang

Keyword(s):

Dimensional Analysis ◽

Approximate Calculation ◽

Blast Loading ◽

Engineering Calculation ◽

Dynamic Responses ◽

Elastic Theory ◽

Thin Plates ◽

Dynamic Parameters ◽

Simply Supported ◽

Reasonable Model

With elastic theory and approximate calculation, the dynamic responses of elastic thin plates with four edges simply supported under blast loading is analyzed in this paper , with dimensional analysis , 30 cases are calculated, and a reasonable model of engineering calculation is built up in the end.

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Modelling and Dynamic Response of Steel Reticulated Shell under Blast Loading

Shock and Vibration ◽

10.1155/2013/540383 ◽

2013 ◽

Vol 20 (1) ◽

pp. 19-28 ◽

Cited By ~ 9

Author(s):

Ximei Zhai ◽

Yonghui Wang

Keyword(s):

Finite Element ◽

Single Layer ◽

Blast Loading ◽

Element Model ◽

Dynamic Responses ◽

Empirical Formulas ◽

Structural Dynamic ◽

Explicit Finite Element ◽

Long Span ◽

Tnt Equivalent

Explicit finite element programme LS-DYNA was used to simulate a long-span steel reticulated shell under blast loading to investigate the structural dynamic responses in this paper. The elaborate finite element model of the Kiewitt-8 single-layer reticulated shell with span of 40 m subjected to central blast loading was established and all the process from the detonation of the explosive charge to the demolition, including the propagation of the blast wave and its interaction with structure was reproduced. The peak overpressure from the numerical analysis was compared with empirical formulas to verify the credibility and applicability of numerical simulation for blast loading. The dynamic responses of the structure under blast loading with different TNT equivalent weights of explosive and rise-span ratios were obtained. In addition, the response types of Kiewitt-8 single-layer reticulated shell subjected to central explosive blast loading were defined.

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Analytical Investigation on non-linear dynamic analysis of reinforced concrete building subjected to blast loading

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/850/1/012012 ◽

2021 ◽

Vol 850 (1) ◽

pp. 012012

Author(s):

R. Prashanthi ◽

S. Elavenil

Keyword(s):

Reinforced Concrete ◽

Time History ◽

Blast Loading ◽

Analytical Investigation ◽

Dynamic Responses ◽

Blast Load ◽

Reinforced Concrete Building ◽

Linear Dynamic ◽

Concrete Building ◽

Non Linear

Abstract The blast explosion causes catastrophic failure of structure both externally and internally. In this work the analytical investigation is carried out on the blast performance of the reinforced concrete building frame. Reinforced concrete building connection is vital in the Moment Resistant Frames (MRF) and they play a vital role under constant blast load. It is important to design the building for blast loading since they are subjected to large displacements. The non-linear dynamic behavior of the building by time history analysis method is performed by using SAP2000 finite element stimulation software. Blast load is idealized as the triangular pulse for single degree of freedom system and the effect of the blast load at a different standoff distances on the building element is examined. The analytical method could predict the overall flexural, non-linear shear behavior and ductile response of the building at different modes. The results of the stimulations for various failure conditions such as maximum displacement, maximum base shear and spectral acceleration as per IS 1893-2016 for non-linear dynamic responses are investigated in this study.

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