scholarly journals Experimental and Numerical Study of Ballistic Resistance of Composites Based on Sandwich Metallic Foams

2021 ◽  
Author(s):  
Anna Dmitruk ◽  
Krzysztof Naplocha ◽  
Joanna Pach ◽  
Dariusz Pyka ◽  
Grzegorz Ziółkowski ◽  
...  
Keyword(s):  
Impact Load ◽  
Numerical Study ◽  
Absorption Capacity ◽  
Polymer Materials ◽  
Metallic Foams ◽  
Ballistic Resistance ◽  
Polyurethane Resin ◽  
Computed Microtomography ◽  
Ct System ◽  
The Impact

AbstractIn recent years, hybrid composite materials are of increasing interest during the search for new materials to be used as ballistic barriers (shields) and kinetic energy absorbers. The main objective of this study is to test the energy absorption capacity of Zn-Al alloys filled with various polymer materials (epoxy resin, polyurethane resin and silicone). The ballistic resistance of modern hybrid materials to direct firing of a 5.56 × 45 mm SS109 projectile and during quasi-static piercing test is examined. Next, a numerical simulation in the ABAQUS environment is performed. In order to accurately reproduce the foam structure, a computed microtomography (CT) system is used. In the simulation of deformations of viscoplastic bodies, the Lagrange and Smoothed Particle Hydrodynamic (SPH) methods are applied. The obtained results from numerical analyses are verified with experimental results. Metallic foams are proven to have only a remote influence on the impact load, while, when filled with polyurethane resin, they show resistance to the overshoot. Performed simulation supports the detailed analysis of the impact energy dissipation for each of the samples.

scholarly journals Failure Characteristics of Joint Bolts in Shield Tunnels Subjected to Impact Loads from a Derailed Train

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Qixiang Yan ◽  
Zhixin Deng ◽  
Yanyang Zhang ◽  
Wenbo Yang
Keyword(s):  
Impact Load ◽  
Numerical Study ◽  
Design Method ◽  
Shield Tunnel ◽  
Failure Behavior ◽  
Impact Loads ◽  
Fe Model ◽  
Fe Modelling ◽  
Bolt Failure ◽  
The Impact

Impact loads generated by derailed trains can be extremely high, especially in the case of heavy trains running at high speeds, which usually cause significant safety issues to the rail infrastructures. In shield tunnels, such impact loads may not only cause the damage and deformation of concrete segments, but also lead to the failure of segmental joint bolts. This paper presents a numerical study on the failure behavior of segmental joint bolts in the shield tunnel under impact loading resulting from train derailments. A three-dimensional (3D) numerical model of a shield tunnel based on the finite element (FE) modelling strategy was established, in which the structural behavior of the segmental joint surfaces and the mechanical behavior of the segmental joint bolts were determined. The numerical results show that the occurrence of bolt failure starts at the joints near the impacted segment and develops along the travel direction of train. An extensive parametric study was subsequently performed and the influences of the bolt failure on the dynamic response of the segment were investigated. In particular, the proposed FE model and the analytical results will be used for optimizing the design method of the shield tunnel in preventing the failure of the joint bolts due to the impact load from a derailed HST.

Numerical Study on the Anti-Ballistic Properties of Metal Encapsulating Ceramic Composite Armors

2015 ◽  
Vol 723 ◽  
pp. 26-30 ◽  
Author(s):  
Jiang Ren Lu ◽  
Xin Li Sun ◽  
Xing Hui Cai ◽  
San Qiang Dong ◽  
Guo Liang Wang
Keyword(s):  
Ceramic Composite ◽  
Numerical Study ◽  
Three Dimensional ◽  
Ceramic Block ◽  
Ballistic Resistance ◽  
Limit Velocity ◽  
Ballistic Properties ◽  
Ballistic Limit Velocity ◽  
The Impact ◽  
Two Hybrid

The impact responses and ballistic resistance of the metal encapsulating ceramic composite armors with same area density and two hybrid cores are investigated. The hybrid cores include square metallic lattice with ceramic block insertions, and square metallic lattice with ceramic ball insertions and void-filling epoxy resin. Three-dimensional (3D) finite element (FE) simulations are carried out for each composite armors impacted by bullet with 12.7mm diameter. The focus is placed on the energy absorption capabilities and ballistic limit velocity of different composite armors. Results indicate that two kind of armors can improve the ballistic resistance properties and save mass of 22% and 25% compared to the homogeneous 4340 steel, respectively.

Experimental Investigation of Ice Mass Hydrodynamic Interaction With Offshore Structure in Close Proximity

2015 ◽  
Author(s):  
Tanvir Mehedi Sayeed ◽  
Bruce Colbourne ◽  
Heather Peng ◽  
Benjamin Colbourne ◽  
Don Spencer
Keyword(s):  
Hydrodynamic Interaction ◽  
Impact Load ◽  
Numerical Study ◽  
Numerical Models ◽  
Offshore Structures ◽  
Ocean Engineering ◽  
Offshore Structure ◽  
Area Of Interest ◽  
Close Proximity ◽  
The Impact

Iceberg/bergy bit impact load with fixed and floating offshore structures and supply ships is an important design consideration in ice-prone regions. Studies tend to divide the iceberg impact problem into phases from far field to contact. This results in a tendency to over simplify the final crucial stage where the structure is impacted. The authors have identified knowledge gaps and their influence on the analysis and prediction of iceberg impact velocities and loads (Sayeed et. al (2014)). The experimental and numerical study of viscous dominated very near field region is the main area of interest. This paper reports preliminary results of physical model tests conducted at Ocean Engineering Research Center (OERC) to investigate hydrodynamic interaction between ice masses and fixed offshore structure in close proximity. The objective was to perform a systematic study from simple to complex phenomena which will be a support base for the development of subsequent numerical models. The results demonstrated that hydrodynamic proximity and wave reflection effects do significantly influence the impact velocities at which ice masses approach to large structures. The effect is more pronounced for smaller ice masses.

scholarly journals Correction to: Experimental and Numerical Study of Ballistic Resistance of Composites Based on Sandwich Metallic Foams

2021 ◽  
Author(s):  
Anna Dmitruk ◽  
Krzysztof Naplocha ◽  
Joanna Pach ◽  
Dariusz Pyka ◽  
Grzegorz Ziółkowski ◽  
...  
Keyword(s):  
Numerical Study ◽  
Metallic Foams ◽  
Ballistic Resistance

Energy Absorption of All-Metallic Corrugated Sandwich Cylindrical Shells Subjected to Axial Compression

2020 ◽  
Vol 87 (12) ◽  
Author(s):  
Pengbo Su ◽  
Bin Han ◽  
Mao Yang ◽  
Zhongnan Zhao ◽  
Feihao Li ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
High Speed ◽  
Impact Load ◽  
Cylindrical Shells ◽  
Dynamic Effect ◽  
Absorption Capacity ◽  
Amplification Coefficient ◽  
Displacement Curve ◽  
The Impact

Abstract The energy adsorption properties of all-metallic corrugated sandwich cylindrical shells (CSCSs) subjected to axial compression loading were investigated by the method combining experiments, finite element (FE) simulations, and theoretical analysis. CSCS specimens manufactured using two different methods, i.e., high-speed wire-cut electric discharge machining (HSWEDM) and extrusion, were tested under axial compression. While specimens fabricated separately by HSWEDM and extrusion both exhibited a stable crushing behavior, the extruded ones were much more applicable as lightweight energy absorbers because of their good energy absorption capacity, repeatability, and low cost. The numerically simulated force–displacement curve and the corresponding deformation morphologies of the CSCS compared well with those obtained from experiments. The specific folding deformation mode was revealed from both experiments and simulations. Subsequently, based upon the mode of folding deformation, a theoretical model was established to predict the mean crushing force of the CSCS construction. It was demonstrated that CSCSs with more corrugated units, smaller value of tc/tf and W/Ro could dissipate more impact energy. Such sandwich cylindrical shells exhibited better energy absorption than monolithic cylindrical shells, with an increase of at least 30%. Ultimately, the dynamic effect under the impact load was further evaluated. The dynamic amplification coefficient of CSCS decreased with the increase of the wall thickness.

A Composite Consisting of a Set of Hexagonal Ceramic Bars - The Numerical Study of the Ballistic Resistance

2011 ◽  
Vol 471-472 ◽  
pp. 1142-1146 ◽  
Author(s):  
Sebastian Stanislawek ◽  
Andrzej Morka ◽  
Tadeusz Niezgoda
Keyword(s):  
Reference Model ◽  
Numerical Study ◽  
Rigid Wall ◽  
Material Behavior ◽  
Aluminum Plate ◽  
Three Dimension ◽  
Projectile Impact ◽  
Ballistic Resistance ◽  
Behavior Simulation ◽  
The Impact

The paper presents a numerical study of a double layer composite panels impacted by a AP (Armor Piercing) 51WC projectile. The standard panel is built with aluminum and Al2O3 ceramic continuum layers while the studied model consists of the same aluminum plate but the front one is built with a set of hexagonal ceramic bars. The bar width and the impact position influence on the ballistic resistance are analyzed and compared with the reference solution. The problem has been solved with the usage of the modeling and simulation methods as well as finite elements method implemented in LS-DYNA software. Space discretization for each option was built by three dimension elements guarantying satisfying accuracy of the calculations. For material behavior simulation specific models including the influence of the strain rate and temperature changes were considered. Projectile Tungsten Curbide and aluminum plate material were described by Johnson-Cook model and ceramic target by Johnson-Holmquist model. In the studied panels the area surrounding back edges was supported by a rigid wall. The obtained results show interesting properties of the examined structures considering their ballistic resistance. All tests has given clear results about ballistic protection panel response under WC projectile impact. Panels consisting of sets of hexagonal ceramic bars are slightly easier to penetrate, reference model is stronger by 19% for smaller bars and by only 7% for bigger rods. Despite this fact, the ceramic layer is much less susceptible to overall destruction what makes it more applicable for the armor usage. Furthermore, little influence of the projectile impact point and consequently a part of the bar which is first destroyed is proved.

scholarly journals Numerical study on the impact response of aircraft fuselage structures subjected to large-size tire fragment

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987774
Author(s):  
Senqing Jia ◽  
Fusheng Wang ◽  
Lingjun Yu ◽  
Zheng Wei ◽  
Bin Xu
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Impact Load ◽  
Numerical Study ◽  
Aircraft Fuselage ◽  
Finite Element Software ◽  
Large Size ◽  
The Difference ◽  
The Impact ◽  
Critical Damage

By applying finite element software ANSYS/LS-DYNA, finite element models of front bulkhead and main cabin are established, which aims to assess the dynamic response of fuselage structures impacted by tire fragment under bursting mode. Besides, dynamic characteristics of the two fuselage structures impacted by tire fragment are simulated and critical damage velocities of each working condition are obtained. The results show that composite front bulkhead cannot bear the impact load of front tire fragment at the velocity of 100 m/s, but aluminum alloy front bulkhead can. Main cabin with two properties both can bear the impact loads of front and main tire fragments. When impacted by front tire fragment, critical damage velocity of front bulkhead is approximately half of that of main cabin, while critical damage velocity of aluminum alloy fuselage is larger than that of composite fuselage. However, when impacted by main tire fragment, critical damage velocity of aluminum alloy main cabin is less than that of composite main cabin. Furthermore, maximum contact pressure of composite fuselage is 3–3.3 times than that of aluminum alloy fuselage. The difference in concave deformation is not significant when impacted by front tire fragment, but the difference is great when impacted by main tire fragment.

scholarly journals Experimental and Numerical Study on the Strain Behavior of Buried Pipelines Subjected to an Impact Load

2019 ◽  
Vol 9 (16) ◽  
pp. 3284 ◽  
Author(s):  
Feifei Dong ◽  
Xuemeng Bie ◽  
Jiangping Tian ◽  
Xiangdong Xie ◽  
GuoFeng Du
Keyword(s):  
Finite Element ◽  
Impact Load ◽  
Numerical Study ◽  
Scale Model ◽  
Peak Strain ◽  
Buried Pipeline ◽  
Buried Pipelines ◽  
Strain Behavior ◽  
Geological Conditions ◽  
The Impact

Long-distance oil and gas pipelines are inevitably impacted by rockfalls during geologic hazards such as mud-rock flow and landslides, which have a serious effect on the safe operation of pipelines. In view of this, an experimental and numerical study on the strain behavior of buried pipelines under the impact load of rockfall was developed. The impact load exerted on the soil, and the strains of buried pipeline caused by the impact load were theoretically derived. A scale model experiment was conducted using a self-designed soil-box to simulate the complex geological conditions of the buried pipeline. The simulation model of hammer–soil–pipeline was established to investigate the dynamic response of the buried pipeline. Based on the theoretical, experimental, and finite element analysis (FEA) results, the overall strain behavior of the buried pipeline was obtained and the effects of parameters on the strain developments of the pipelines were analyzed. Research results show that the theoretical calculation results of the impact load and the peak strain were in good agreement with the experimental and FEA results, which indicates that the mathematical formula and the finite element models are accurate for the prediction of pipeline response under the impact load. In addition, decreasing the diameter, as well as increasing the wall thickness of the pipeline and the buried depth above the pipeline, could improve the ability of the pipeline to resist the impact load. These results could provide a reference for seismic design of pipelines in engineering.

scholarly journals Experimental and numerical study of axially-loaded RC columns and frame columns under lateral impact loading

2021 ◽  
Author(s):  
Zheng Luo ◽  
Wang Yinhui
Keyword(s):  
Impact Load ◽  
Numerical Study ◽  
Impact Resistance ◽  
Impact Excitation ◽  
Lateral Impact ◽  
Axial Loads ◽  
Free Standing ◽  
Positive Role ◽  
The Moment ◽  
The Impact

The pendulum impact tests were carried out on one RC frame column and four RC free-standing columns. The effect of axial compression ratio and reinforcement ratio on the impact resistance of columns were compared by means of dynamic time curves of framed and freestanding columns under impact. The test results show that with the same impact load, though the presence of axial loads can play a positive role (e.g., reducing the residual displacement), it may lead to more severe local damage. Also, compared with free-standing columns, the frame column can be considered as a protective structure for its greater lateral stiffness and stronger crashworthiness. The corresponding finite element models are developed，and the influence of the axial loads on cross section force responses under impact excitation is deeply explored. The axial loads can significantly affect the distribution of the moment, the shear force, and also the damage for the column.

scholarly journals Crushing Behaviour of the PVC Foam Loaded with Beaters of Various Shapes

2018 ◽  
Vol 12 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Paweł Bogusz ◽  
Roman Gieleta ◽  
Marcin Konarzewski ◽  
Michał Stankiewicz
Keyword(s):  
Police Officers ◽  
Short Distance ◽  
Small Area ◽  
Impact Load ◽  
Foam Material ◽  
Dynamic Impact ◽  
Drop Hammer ◽  
Ballistic Resistance ◽  
Different Shapes ◽  
The Impact

AbstractStatistically, at least 50% of all injuries experienced by police officers in the line of duty are due to assaults with blunt objects. Therefore, vests used by the police should provide not only good ballistic resistance, but also good protection against such threats. Foamed materials are possible to be used for body protectors or inserts of protective clothes. The effects of dynamic impact with beaters of different shapes onto behaviour of polymeric foamed material were determined. There were used four types of beaters: flat, cylindrical, edgy and cornered. Strikes with blunt objects such as a flat board, baseball bat, edgy brick, pavement brick or a sharp stone, to which a protective ware can be subjected, were simulated. The impact load was applied to the rectangular specimens, made of polyvinyl chloride foam, with a usage of a drop hammer. Plots of force versus compression for all the tested samples were obtained and analysed. The effects of impacts with beaters of different shapes onto foamed material samples were presented. A shape of the blunt object significantly influences crushing behaviour of the foamed material. The impact energy of a flat beater is absorbed effectively on a short distance, since it is spread on a relatively large surface. The cylindrical and edgy beaters did not cause fragmentation of the samples, however, on the upper surfaces of the samples, permanent deformations mapping the beaters shapes as well as some cracks occurred. An impact with a sharp object, for example, a cornered beater is very difficult to be neutralized by the foam material, because it is cumulated on a small area.

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