scholarly journals Experimental Study on the Impact Resistance of Closed-Cell Aluminum Foam Protective Materials to RC Piers under Lateral Impact

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Xiwu Zhou ◽  
Wen Zhang ◽  
Xiangyu Wang ◽  
Wenchao Zhang ◽  
Meng Zhan
Keyword(s):  
Impact Energy ◽  
Aluminum Foam ◽  
Impact Force ◽  
Experimental Testing ◽  
Test System ◽  
Protective Effects ◽  
Lateral Impact ◽  
Cumulative Impact ◽  
Closed Cell ◽  
The Impact

In this study, the lateral impact tests of six RC piers which were protected by closed-cell aluminum foam (CCAF) were carried out by making use of an ultrahigh drop hammer horizontal impact test system. The protective effects of CCAF with different densities on the piers were then analyzed. The data regarding the piers’ impact force, displacement, reinforcement strain, and crack and damage development were mainly collected during the experimental testing processes. The results indicated that, when the impact energy was less than 7258 J and the density of the CCAF was 0.45 g/cm3, the cumulative impact force and displacements of the piers decreased by 67% and 35%, respectively. Therefore, it was considered that the CCAF with a density of 0.45 g/cm3 had displayed the best protective effects at that stage. It was also observed that when the impact energy was greater than 7258 J and the density of the CCAF was 0.55 g/cm3, the cumulative impact force and displacements of the piers decreased by 25% and 18%, respectively. Therefore, the CCAF with a density of 0.55 g/cm3 had displayed the best protective effects at that stage. Furthermore, under the conditions of constant accumulative impact energy, the protective effects of CCAF on the piers were observed to be weakened if it entered the densification stage too early and high-yield platforms were formed due to the density levels becoming too high. However, it was found that reasonable density and thickness increases could effectively delay the entry of CCAF into the densification stage, which effectively reduced the shearing effects which occurred when the impact speeds were too high, thereby preventing the shear failure of the piers.

scholarly journals Torsion Property of the Structure Bonded Aluminum Foam Due to Impact

2017 ◽  
Vol 62 (2) ◽  
pp. 1353-1357
Author(s):  
G.W. Hwang ◽  
J.U. Cho
Keyword(s):  
Impact Energy ◽  
Aluminum Foam ◽  
Bonding Interface ◽  
Cell Type ◽  
Aluminum Foams ◽  
Fracture Characteristics ◽  
Foaming Agent ◽  
Closed Cell ◽  
The Impact ◽  
Torsion Property

AbstractAn aluminum foam added with foaming agent, is classified into an open-cell type for heat transfer and a closed-cell type for shock absorption. This study investigates the characteristic on the torsion of aluminum foam for a closed-cell type under impact. The fracture characteristics are investigated through the composite of five types of aluminum foam (the thicknesses of 25, 35, 45, 55 and 65 mm), when applying the torsional moment of impact energy on the junction of a porous structure attached by an adhesive. When applying the impact energy of 100, 200 and 300J, the aluminum foams with thicknesses of 25 mm and 35 mm broke off under all conditions. For the energy over 200J, aluminums thicker than 55 mm continued to be attached. Furthermore, the aluminum specimens with thicknesses of 55 mm and 65 mm that were attached with more than 30% of bonding interface remained, proving that they could maintain bonding interface against impact energy. By comparing the data based on the analysis and test result, an increase in the thickness of specimen leads to the plastic deformation as the stress at the top and bottom of bonding interface moves to the middle by spreading the stress horizontally. Based on this fracture characteristic, this study can provide the data on the destruction and separation of bonding interface and may contribute to the safety design.

scholarly journals Study on the Influence of Closed-Cell Aluminum Foam on the Impact Performance of Concrete Pier after Equal Replacement with Stainless Steel Reinforcement

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiwu Zhou ◽  
Honglong Zhang ◽  
Wenchao Zhang ◽  
Guoxue Zhang
Keyword(s):  
Stainless Steel ◽  
Aluminum Foam ◽  
Impact Test ◽  
Impact Force ◽  
Steel Reinforcement ◽  
Change Rate ◽  
Damage Rate ◽  
Closed Cell ◽  
Ultrasonic Damage ◽  
The Impact

In this study, the impact test of two groups of reinforced concrete piers protected by closed-cell aluminum foam is carried out by using the ultrahigh drop hammer impact test system. The purpose of this study is to explore the impact resistance and protective performance of closed-cell aluminum foam under the impact load on the concrete bridge pier after replacing the ordinary reinforcement with stainless steel reinforcement. The study results show that the impact force is related to the overall stiffness of the specimen, as well as to the failure mode. When the impact velocity is less than 1.42 m/s, the closed-cell aluminum foam is in an elastic or yielding stage. The change rate of impact force (231 and 97.5, respectively), tip displacement (33.5 and 18, respectively), and ultrasonic damage rate of the concrete in the two groups of specimen is relatively small, while the change rate of the two groups of specimen remains approximately consistent. In addition, when the impact is greater than 1.42 m/s and the closed-cell aluminum foam is in the densification stage, the change rate of the impact force (increase from 231 to 819 and from 97.5 to 984.5), the tip displacement (increase from 33.5 to 67 and from 18 to 62), and ultrasonic damage rate of concrete are larger, which results in an increase in the dynamic response of the structure.

scholarly journals Numerical research on impact performance of bridge columns with aluminum foam protection devices

2020 ◽  
Vol 16 (11) ◽  
pp. 155014772097453
Author(s):  
Yuye Zhang ◽  
Ruiyang Pan ◽  
Feng Xiao
Keyword(s):  
Aluminum Foam ◽  
Maximum Stress ◽  
Impact Force ◽  
Bridge Columns ◽  
Design Parameters ◽  
Protection Device ◽  
Impact Performance ◽  
Positive Effects ◽  
Protection Capability ◽  
The Impact

This article presents a new protection device using aluminum foam to enhance the impact resistance of bridge columns. First, the protection device is designed according to the characteristics of aluminum foam material. The geometric configuration and structure of the device are described. Second, the impact performance of bridge column is analyzed, including impact force analysis, damage analysis, and the influence of axial load. Third, three-dimensional solid element models of columns with and without the protection device are developed in order to verify the effect of the protection device. By comparing dynamic responses of vehicle impact on columns with and without the protection device, it is considered that the protection device has certain protection effect: after installing the protective device, the peak value of impact force reduces by 37.5%, the maximum displacement of column top reduces by 23.7%, the maximum stress at column bottom reduces by 51.6%, the maximum stress at column bottom reduces by 51.6%, the maximum acceleration of the vehicle reduces by 40.6%, and 86.84% of the impact energy is absorbed by the protection device. Finally, the devices with different foam thicknesses and porosities are comparatively analyzed to investigate the influence of these design parameters on impact performance. The results show that the increase in the thickness of aluminum foam has positive effects on the protection capability. The protection capability improves with aluminum foam porosity increasing when the porosity is less than 60%.

Dynamic Energy Absorption Performances of Rain Forest Vehicle (RFV) under Frontal Impact

2014 ◽  
Vol 67 (3) ◽  
Author(s):  
M. S. Othman ◽  
Z. Ahmad
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Impact Loading ◽  
Rain Forest ◽  
Experimental Testing ◽  
Rigid Wall ◽  
Crash Analysis ◽  
Frontal Impact ◽  
Frontal Section ◽  
The Impact

This paper treats the crash analysis and energy absorption response of Rain Forest Vehicle (RFV) subjected to frontal impact scenario namely impacting rigid wall and column. Dynamic computer simulation techniques validated by experimental testing are used to carry out a crash analysis of such vehicle. The study aims at quantifying the energy absorption capability of frontal section of RFV under impact loading, for variations in the load transfer paths and geometry of the crashworthy components. It is evident that the proposed design of the RFV frontal section are desirable as primary impact energy mitigation due to its ability to withstand and absorb impact loads effectively. Furthermore, it is found that the impact energy transmitted to the survival room may feasibly be minimized in these two impact events. The primary outcome of this study is design recommendation for enhancing the level of safety of the off-road vehicle where impact loading is expected.   

scholarly journals Study on Concrete Pier Impact Performance after Implementing Equal Cross-Section Stainless Steel with Protection from Closed-Cell Aluminum Foam

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiwu Zhou ◽  
Honglong Zhang ◽  
Wenchao Zhang ◽  
Guoxue Zhang
Keyword(s):  
Stainless Steel ◽  
Reinforced Concrete ◽  
Aluminum Foam ◽  
Bridge Piers ◽  
Concrete Bridge ◽  
Reinforced Concrete Bridge ◽  
Impact Forces ◽  
Closed Cell ◽  
Steel Bars ◽  
The Impact

In the present study, in order to examine the impact performances of ordinary reinforced concrete bridge piers which have been replaced by stainless-steel bars of equal cross-sections under the protective condition of anticollision material, the impact dynamic responses of the ordinary reinforced concrete bridge piers, with replacements under the protection of closed-cell aluminum foam, were compared and analyzed using an ultrahigh drop hammer impact test system. The results showed that when the impact velocity was small (for example, less than 1.42 M/s), after the implementation of equal cross-sectional replacements, the closed-cell aluminum foam had been in an elastic or yield stage. During that stage, the impact forces of the stainless-steel reinforced concrete piers were larger than those of the ordinary reinforced concrete piers, and the relative ratios were stable at approximately 28 to 34%. In addition, the relative ratios of the displacements at the tops of the components were also found to be stable at approximately 22%, and the change rates of the concrete ultrasonic damages were approximately the same. However, when the impact forces had increased (for example, more than 1.67 m/s), the closed-cell aluminum foam entered a densification stage, and the peak impact force ratios decreased sharply. It was also observed that the relative peak displacement ratios at the tops of the components displayed increasing trends, and the change rates of the concrete ultrasonic damages had displayed major flux. Therefore, the replacement of the ordinary piers with stainless-steel bars had increased the possibility of shear failures.

Dynamic Energy Absorption Performances of Rain Forest Vehicle (RFV) under Frontal Impact

2014 ◽  
Vol 69 (3) ◽  
Author(s):  
M. S. Othman ◽  
Z. Ahmad
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Impact Loading ◽  
Rain Forest ◽  
Experimental Testing ◽  
Rigid Wall ◽  
Crash Analysis ◽  
Frontal Impact ◽  
Frontal Section ◽  
The Impact

This paper treats the crash analysis and energy absorption response of Rain Forest Vehicle (RFV) subjected to frontal impact scenario namely impacting rigid wall and column. Dynamic computer simulation techniques validated by experimental testing are used to carry out a crash analysis of such vehicle. The study aims at quantifying the energy absorption capability of frontal section of RFV under impact loading, for variations in the load transfer paths and geometry of the crashworthy components. It is evident that the proposed design of the RFV frontal section are desirable as primary impact energy mitigation due to its ability to withstand and absorb impact loads effectively. Furthermore, it is found that the impact energy transmitted to the survival room may feasibly be minimized in these two impact events. The primary outcome of this study is design recommendation for enhancing the level of safety of the off-road vehicle where impact loading is expected.   

Impact Energy Measurement of a Hydraulic Breaker

2006 ◽  
Vol 326-328 ◽  
pp. 1669-1672
Author(s):  
Jong Won Park ◽  
Hyoung Eui Kim
Keyword(s):  
Construction Industry ◽  
Impact Energy ◽  
High Speed ◽  
Test System ◽  
Hydraulic Power ◽  
Construction Machinery ◽  
Road Pavement ◽  
Hydraulic Cylinders ◽  
The Impact ◽  
Test Process

A hydraulic breaker for construction machinery generally used for the destroying and disassembling of buildings, crashing road pavement, breaking rocks at quarry and so on. So the measurement of the impact energy of a hydraulic breaker is very important thing to prove its capability to manufacturers and customers. In this study, the test system for measuring the impact energy of a hydraulic breaker was designed and constructed. The test system was consisted with hydraulic cylinders for mounting a breaker, impact absorbing base and frames, pressure and flow sensors, high speed and accurate data acquisition system diesel engine driven hydraulic power unit. The test process of the developed system was carried by measuring guide for tool energy rating for hydraulic breakers which was developed by the CIMA (Construction Industry Manufacturers Association) USA. The developed test system can be applied to measure the impact energy for various kinds of hydraulic breakers.

scholarly journals Parameter Analysis on the Anti-Impact Behavior of Pcfst Columns under Lateral Impact Load

2018 ◽  
Vol 206 ◽  
pp. 01020
Author(s):  
W Xu ◽  
A Z Zhu ◽  
K Gao
Keyword(s):  
Yield Strength ◽  
Impact Energy ◽  
Impact Load ◽  
Parameter Analysis ◽  
Impact Behavior ◽  
Lateral Impact ◽  
Fea Model ◽  
Filling Height ◽  
Concrete Filling ◽  
The Impact

Concrete-filled steel tubular (CFST) structures have been widel y used in civil engineering structures, due to its good behaviors under both static and dynamic loads. In this paper, numerical studies were carried out to investigate the anti-impact behavior of partially concrete-filled steel tubular (PCFST) columns under lateral impact loads. Finite element analysis (FEA) model was established using ABAQUS. To validate the FEA model, the numerical results were compared with experimental results. Moreover, parameter analysis was carried out to further study the anti-impact behaviors of the PCFST columns. The concrete filling height, the impact energy, the impact direction, and the yield strength of steel were the main parameters considered in this study. The dynamic responses under the impact load, including the impact force, the failure mode, and the displacement response, were all analyzed. The results of parameter analysis showed that the anti-impact behaviors of the PCFST columns significantly increased when the concrete filling height or the yield strength of steel increased greatly. The impact energy and direction also greatly affected the anti-impact behaviors of the PCFST columns.

scholarly journals Experimental study on damage evaluation of stainless steel–reinforced concrete piers under lateral impact

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402092488
Author(s):  
Bo Wu ◽  
Shixiang Xu
Keyword(s):  
Stainless Steel ◽  
Reinforced Concrete ◽  
Impact Damage ◽  
Test System ◽  
Reinforcement Ratio ◽  
Test Results ◽  
Lateral Impact ◽  
Steel Reinforced Concrete ◽  
Steel Bars ◽  
The Impact

Horizontal impact tests of stainless steel–reinforced concrete piers with different reinforcement ratios at different impact velocities were carried out by using the ultra-high drop weight impact test system. Degree of piers damage after impact was comprehensively analyzed by measuring the acceleration of the impact body, the displacement of the top of the pier specimens, the strain of the steel bars, the rotation of the pier bottom, and the crack development of concrete. The test results showed that under the same impact velocity, with the decrease in reinforcement ratio, the peak acceleration of the impact body, the displacement of the top of pier specimens, the strain of steel bars, and the pier bottom rotation all increase. To a certain extent, increasing the reinforcement ratio of bridge piers can effectively reduce impact damage.

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