Energy Absorption Capacity Of Empty And Foam Filled Mild Steel Tube Under Low Strain Rate At Room Temperature

2015 ◽  
Vol 6 (6) ◽  
pp. 548-553 ◽  
Author(s):  
Dipen Kumar Rajak
Keyword(s):  
Mild Steel ◽  
Strain Rate ◽  
Energy Absorption ◽  
Room Temperature ◽  
Steel Tube ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Foam Filled ◽  
Low Strain Rate

scholarly journals Static Mechanical Properties of Expanded Polypropylene Crushable Foam

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 249
Author(s):  
Przemysław Rumianek ◽  
Tomasz Dobosz ◽  
Radosław Nowak ◽  
Piotr Dziewit ◽  
Andrzej Aromiński
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Strain Rate ◽  
Energy Absorption ◽  
Experimental Tests ◽  
Absorption Capacity ◽  
Strain Rates ◽  
Foam Density ◽  
Energy Absorption Capacity ◽  
Closed Cell

Closed-cell expanded polypropylene (EPP) foam is commonly used in car bumpers for the purpose of absorbing energy impacts. Characterization of the foam’s mechanical properties at varying strain rates is essential for selecting the proper material used as a protective structure in dynamic loading application. The aim of the study was to investigate the influence of loading strain rate, material density, and microstructure on compressive strength and energy absorption capacity for closed-cell polymeric foams. We performed quasi-static compressive strength tests with strain rates in the range of 0.2 to 25 mm/s, using a hydraulically controlled material testing system (MTS) for different foam densities in the range 20 g/dm3 to 220 g/dm3. The above tests were carried out as numerical simulation using ABAQUS software. The verification of the properties was carried out on the basis of experimental tests and simulations performed using the finite element method. The method of modelling the structure of the tested sample has an impact on the stress values. Experimental tests were performed for various loads and at various initial temperatures of the tested sample. We found that increasing both the strain rate of loading and foam density raised the compressive strength and energy absorption capacity. Increasing the ambient and tested sample temperature caused a decrease in compressive strength and energy absorption capacity. For the same foam density, differences in foam microstructures were causing differences in strength and energy absorption capacity when testing at the same loading strain rate. To sum up, tuning the microstructure of foams could be used to acquire desired global materials properties. Precise material description extends the possibility of using EPP foams in various applications.

Effects of aluminum foam filling on the low-velocity impact response of sandwich panels with corrugated cores

2018 ◽  
Vol 22 (4) ◽  
pp. 929-947 ◽  
Author(s):  
LL Yan ◽  
B Yu ◽  
B Han ◽  
QC Zhang ◽  
TJ Lu ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Aluminum Foam ◽  
Sandwich Panel ◽  
Absorption Capacity ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Energy Absorption Capacity ◽  
Core Member ◽  
Foam Filling ◽  
Foam Filled

In this study, a closed-cell aluminum foam was filled into the interspaces of a sandwich panel with corrugated cores to form a composite structure. The novel structure is expected to have enhanced foam-filled cores with high specific strength and energy absorption capacity. An out-of-plane compressive load under low-velocity impact was experimentally and numerically carried out on both the empty and foam-filled sandwich panels as well as on the aluminum foam. It is found that the empty corrugated sandwich panel has poor energy absorption capacity due to the core member buckling compared to that of the aluminum foam. However, by the filling of the aluminum foam, the impact load resistance of the corrugated panel was increased dramatically. The loading-time response of the foam-filled panel performs a plateau region like the aluminum foam, which has been proved to be an excellent energy absorption material. Numerical results demonstrated that the aluminum foam filling can decrease the corrugated core member defects sensitivity and increase its stability dramatically. The plastic energy dissipation of the core member for the foam-filled panel is much higher than that of the empty one due to the reduced buckling wavelength caused by the aluminum foam filling.

Energy Absorption Characteristics of Polyurethane Composite Foam-Filled Tubes Subjected to Quasi-Static Axial Loading

2013 ◽  
Vol 315 ◽  
pp. 872-878 ◽  
Author(s):  
S. Kanna Subramaniyan ◽  
Shahruddin Mahzan ◽  
Mohd Imran Ghazali ◽  
Ahmad Mujahid Ahmad Zaidi ◽  
Prasath Kesavan Prabagaran
Keyword(s):  
Energy Absorption ◽  
Testing Machine ◽  
Axial Loading ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Composite Foam ◽  
Polyurethane Composite ◽  
Pu Foam ◽  
Foam Filled ◽  
Recycled Material

Foam-filled enclosures are very common in structural crashworthiness to increase energy absorption. However, very less research has been targeted on potential use of natural/recycled material reinforced foam-filled tubes. Therefore, an experimental investigation was performed to quantify energy absorption capacity of polyurethane (PU) composite foam-filled circular steel tubes under quasi-static axial loading. The thickness of the tubes was varied from 1.9, 2.9 and 3.6 mm. The tubes were filled with PU composite foam. The PU composite foam was processed with addition of kenaf plant fiber and recycled rubber particles that were refined at 80 mesh particulates into PU system. The density of PU resin was varied from 100, 200 and 300 kgm-3. The PU composite foam-filled tubes were crushed axially at constant speed in a universal testing machine and their energy absorption was characterized from the resulting load-deflection data. Results indicate that PU composite foam-filled tubes exhibited better energy absorption capacity than those PU foam-filled tubes and its respective empty tubes. Interaction effect between the tube and the foam and incorporation of filler into PU system led to an increase in mean crushing load compared to that of the unfilled PU foam or tube itself. Relatively, progressively collapse modes were observed for all tested tubes. Findings suggested that composite foam-filled tubes could be used as crashworthy member.

scholarly journals CFRP Reinforced Foam Concrete Subjected to Dynamic Compression at Medium Strain Rate

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 10 ◽  
Author(s):  
Xiaojuan Wang ◽  
Lu Liu ◽  
Wenjing Shen ◽  
Hongyuan Zhou
Keyword(s):  
Strain Rate ◽  
Energy Absorption ◽  
Dynamic Compression ◽  
Absorption Capacity ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Foam Concrete ◽  
Energy Absorption Capacity ◽  
Reinforced Polymer ◽  
Medium Strain Rate

Carbon fiber-reinforced polymer (CFRP)-confined foam concrete can be applied in structure protection, e.g., as an impact barrier of bridge piers, in which it is used as the core of the composite impact barrier. Applying CFRP to the foam concrete exterior enhances both the CFRP and the foam concrete, leading to improved compressive performance due to their interaction. In the present study, the carbon-fiber reinforced polymer (CFRP) confining effect on the response and energy absorption of foam concrete subjected to quasi-static and medium-strain-rate dynamic compression was experimentally investigated. The confinement by CFRP changed the response and failure mode of foam concrete specimens from shear in quasi-static load and splitting in dynamic load to crushing, resulting in a significant increase in the load bearing and energy absorption capacity. The composite consisting of CFRP and foam concrete was sensitive to strain rate. In particular, the CFRP–foam concrete interaction led to the remarkably improved resistance and energy absorption capacity of CFRP-confined specimens, which were significantly higher than the sum of those of standalone CFRP and foam concrete.

Effects of Strain Rate on Energy Absorption of High Strength TRIP Steel

2014 ◽  
Vol 552 ◽  
pp. 308-314
Author(s):  
Fei Xiang Yang ◽  
Chao Qun Zhu ◽  
Jun Jie Zhao ◽  
Yan Lin He ◽  
Lin Li
Keyword(s):  
Strain Rate ◽  
Energy Absorption ◽  
Trip Steel ◽  
Static Condition ◽  
Absorption Capacity ◽  
Gradual Transition ◽  
Absorption Properties ◽  
Energy Absorption Capacity ◽  
Dynamic Tension ◽  
Dp Steel

In this paper, the energy absorption properties of 600 MPa and 800MPa grade TRIP and DP steels under different strain rates were investigated. It was shown that the deformation of dynamic specimens concentrated in parallel section under quasi-static stretching, and the strain rate had nothing to do with the energy absorption of these four steel. In the dynamic tension, the TRIP steel had a better energy absorption capacity than it in the quasi-static condition. However, the energy absorption properties of DP steel were not the case. And with the increasing of the strain rate, the energy absorption of these four steel decreased. It was because that instead of “gradual transition”, the transformation of retained austenite changed to “instantaneous transition” in dynamic tension. It made the energy absorption become smaller than it in static tension. Meanwhile, the ductility and the energy absorption capacity of the DP steel were improved, which effected by the adiabatic temperature rise. Owing to suppression of plastic deformation of these steel in dynamic tension, the energy absorption capacity of these four steel decreased with the increasing of strain rate.

scholarly journals Mechanisms of energy absorption in special devices for use in earthquake resistant structures

1972 ◽  
Vol 5 (3) ◽  
pp. 63-88 ◽  
Author(s):  
J. M. Kelly ◽  
R. I. Skinner ◽  
A. J. Heine
Keyword(s):  
Reinforced Concrete ◽  
Kinetic Energy ◽  
Mild Steel ◽  
Energy Absorption ◽  
Earthquake Engineering ◽  
Absorption Capacity ◽  
Concrete Frames ◽  
Energy Absorption Capacity ◽  
Structural Applications ◽  
Energy Absorbing

A structure designed to resist earthquake attack must have a capacity to dissipate kinetic energy induced by the ground motion. In most structures this energy absorption is developed in the vicinity of beam to column connections. Recent research has shown that connections are not reliable when subject to cyclic loading, such as results from earthquake attack. Connections in steel frames deteriorate due to local instabilities in adjacent flanges, and in reinforced concrete frames alternating shear
loads produce diagonal tension and bond failures which progressively reduce the strength of the connection. Much work in building research and earthquake engineering in laboratories throughout the world is directed toward increasing the reliability and energy absorption capacity of structural connections. In this paper an alternative approach to this problem is described. This approach is to separate the load carrying function of the structure from the energy absorbing function and to ask if special devices could be incorporated into the structure with the sole purpose of absorbing the kinetic energy generated in the structure by earthquake attack. To determine whether such devices are feasible a study has been undertaken of three essentially different mechanisms of energy absorption. These mechanisms all utilized the plastic deformation of mild steel. They included the rolling of strips, torsion of square and rectangular bars,
 and the flexure of short thick beams. These mechanisms were selected for intensive study since they were basic to three different types of device each of which was designed for a separate mode of operation in a structural system. The characteristics of these mechanisms which were of primary importance in this study were the load displacement relations, the energy absorption capacity and the fatigue resistance. This information was obtained with a view to the development of devices for specific structural applications. This report describes the tests used to explore the basic mechanisms and the data obtained. It also include s a brief description of tests on scale models of a device which was designed to be located in the piers of a reinforced concrete railway bridge. It has been shown by the tests that the plastic torsion of mild steel is an extremely efficient mechanism for the absorption of energy. It was found that at plastic strains in the range 3% to 12% it was possible to develop energy dissipation of the order of 2000-7500 lb in/in3 per cycle (14-50 x 106 N/M2 per cycle) with lifetimes within the range of 1000 to 100 cycles. It was also shown that the mode of failure in torsion is an extremely favourable one for use in an energy absorbing device in that it took the form of a gradual decay. The other two mechanisms studied were both less efficient and less reliable than torsion and had capacities of 500-2000 lb in/in3 per cycle (3.5 - 14 x 106 N/M2 per cycle) and life times of around 200 to 20 cycles. Nevertheless they lend themselves to more compact devices than does the torsional mechanism and furthermore the devices may be located in regions in a structure where they are readily accessible for replacement after attack.

Uniaxial crushing of constrained tubes

2001 ◽  
Vol 215 (3) ◽  
pp. 353-364 ◽  
Author(s):  
A A Singace ◽  
H El-Sobky
Keyword(s):  
Mild Steel ◽  
Aluminium Alloy ◽  
Energy Absorption ◽  
Radial Direction ◽  
Absorption Capacity ◽  
Displacement Curve ◽  
Energy Absorption Capacity ◽  
Axial Crushing ◽  
The Mean ◽  
Load Displacement

By changing the end constraints, the behaviour of mild steel and aluminium alloy tubes of relatively low D/ t ratio, subjected to an axial crushing load, is studied. Many combinations of end constraints were produced by radially constraining one or both ends of the loaded tube outwards, inwards or in both directions. Partially constrained mild steel and aluminium tubes are found to collapse into either a pure concertina mode or a pure diamond mode, depending on the ratio D/ t and the material characteristics. Mixed concertina-diamond modes would generally result by radially constraining the tube at both ends. Constraining the tube radially outwards at one end does not significantly affect the load-displacement characteristics and the mode of collapse. However, constraining the tube radially inwards produces a different mode than that observed under outward, inward or combined outward/inward constraint. New modes of collapse have been observed under different combinations of outward and inward constraints at both ends. Fully constraining the tubes in the radial direction results in the removal of the initial overshoot in the load-displacement curve, which is responsible for the overestimation of the mean crushing load and the energy absorption capacity of tubular elements. The mode of collapse and the energy absorbed could be controlled with the proper choice of the end constraints.

Response of Filled Thin-Walled Square Tubes to Axial Impact Load

2014 ◽  
Vol 566 ◽  
pp. 586-592
Author(s):  
Steeve Chung Kim Yuen ◽  
Gerald Nurick ◽  
Sylvester Piu ◽  
Gadija Ebrahim
Keyword(s):  
Energy Absorption ◽  
High Speed ◽  
Impact Load ◽  
Absorption Capacity ◽  
Tubular Structures ◽  
Energy Absorption Capacity ◽  
Axial Impact ◽  
Foam Filled ◽  
Thin Walled ◽  
Initial Peak

This paper presents the results of an investigation into the response of thin-walled square (60x60 mm and 76x76 mm) tubes made from mild steel filled with four different fillers; aluminium foam (Cymat 7%), two types of aluminium honeycomb and polyurethane foam to quasi-static and dynamic axial impact load. The energy absorption characteristics of the foam-filled tubes are compared to that of a hollow tube, through efficiency calculations. The tubular structures are subjected to axial impact load generated by drop masses of 320 kg and 390 kg released from a height ranging between 2.1 m to 4.1 m. Footage from a high speed camera is used to determine the average crush forces exerted by each specimen. The results show that the fillers have insignificant effects on the initial peak forces based on the quasi-static results but increase the overall mean crushed force. The findings also indicate that the fillers affect at times the size of the lobe formed thus compromising the energy absorption capacity of the tube.

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