The Energy Absorption Characteristics of Square Mild Steel Tubes With Multiple Induced Circular Hole Discontinuities—Part I: Experiments

2009 ◽  
Vol 76 (4) ◽  
Author(s):  
S. B. Bodlani ◽  
S. Chung Kim Yuen ◽  
G. N. Nurick
Keyword(s):  
Mild Steel ◽  
Energy Absorption ◽  
Circular Hole ◽  
Progressive Collapse ◽  
Experimental Tests ◽  
Absorption Capacity ◽  
Peak Force ◽  
Steel Tubes ◽  
Initial Peak ◽  
Absorption Characteristics

This two-part article reports the results of experimental and numerical works conducted on the energy absorption characteristics of thin-walled square tubes with multiple circular hole discontinuities. Part I presents the experimental tests in which dynamic and quasistatic axial crushings are performed. The mild steel tubes are 350 mm in length, 50 mm wide, and 1.5 mm thick. Circular hole discontinuities, 17 mm in diameter, are laterally drilled on two or all four opposing walls of the tube to form opposing hole pairs. The total number of holes varies from 2 to 10. The results indicate that the introduction of holes decreases the initial peak force but an increase in the number of holes beyond 2 holes per side does not further significantly decrease the initial peak force. The findings show that strategic positioning of holes triggers progressive collapse hence improving energy absorption. The results also indicate that the presence of holes may at times disrupt the formation of lobes thus compromising the energy absorption capacity of the tube. In Part II, the finite element package ABAQUS/EXPLICIT version 6.4–6 is used to model the dynamic axial crushing of the tubes and to investigate the action of the holes during dynamic loading at an impact velocity of 8 m/s.

The Energy Absorption Characteristics of Square Mild Steel Tubes With Multiple Induced Circular Hole Discontinuities—Part II: Numerical Simulations

2009 ◽  
Vol 76 (4) ◽  
Author(s):  
S. B. Bodlani ◽  
S. Chung Kim Yuen ◽  
G. N. Nurick
Keyword(s):  
Numerical Simulations ◽  
Energy Absorption ◽  
Circular Hole ◽  
Tube Wall ◽  
Axial Loading ◽  
Peak Force ◽  
Tube Length ◽  
Finite Element Package ◽  
Initial Peak ◽  
Absorption Characteristics

This paper is Part II of a two-part article and presents the results of numerical simulations conducted to investigate the energy absorption characteristics of square tubes subjected to dynamic axial loading. Part I reports the experimental results of both quasistatic and dynamic tests. The validated model is used to study the crushing characteristics of tubes with multiple induced circular hole discontinuities using the finite element package ABAQUS/EXPLICIT version 6.4-6. Holes of diameter 17 mm are used as crush initiators, which are laterally drilled into the tube wall to form opposing hole pairs. Holes of diameters 12.5 mm and 25 mm are also used to assess the effects of hole diameter on energy absorption. Two hole spacing configurations are investigated, one in which the hole pairs are placed at regular intervals of 50 mm along the tube wall and another in which the hole pairs are spaced symmetrically along the tube length. Holes are also drilled on either two or all four opposing tube walls. The number of holes is varied from 2 to 10. The results indicate that the introduction of the holes decreases the initial peak force. However, an increase in the number of holes, beyond two holes, does not further significantly decrease the initial peak force. A study of the crushing history of the tubes reveals that crushing is initiated at the location of the holes. The results also indicate that the type of hole spacing determines how crushing is initiated at the hole locations. The model satisfactorily predicts the resultant collapse shapes but overpredicts the crushed distance.

Crush Characteristics and Energy Absorption of Thin-Walled Tubes with Through-Hole Crush Initiators

2014 ◽  
Vol 606 ◽  
pp. 181-185 ◽  
Author(s):  
S. Kanna Subramaniyan ◽  
Arun Kumar Kananasan ◽  
Mohd Radzi Mohamed Yunus ◽  
Shahruddin Mahzan ◽  
Mohd Imran Ghazali
Keyword(s):  
Experimental Investigation ◽  
Energy Absorption ◽  
Static Loading ◽  
Absorption Capacity ◽  
Peak Force ◽  
Energy Absorption Capacity ◽  
Steel Tubes ◽  
Thin Walled ◽  
Through Hole ◽  
Initial Peak

An experimental investigation was conducted to compare the crush characteristics and energy absorption capacity of circular and square tubes with located through-hole crush initiator. Circular through-holes were fabricated at three different configurations based on location into steel tubes which had a length of 200 mm. Furthermore, two different side configurations along the tube were considered for introducing the crush initiators. The results found that adding crush initiator onto the tubes were effectively reduced the initial peak force of a thin-walled circular and square tubes under axial quasi-static loading. The peak crush force was reduced within a range 3-10% and 5-16% for circular and square tubes respectively when compared with corresponding tubes without crush initiator. Moreover, the energy absorption capacity of the tubes was independent with the incorporation of through-hole crush initiators. However, the energy absorption of circular and square tubes were slightly decreases when compared with the tubes fabricated four sided crush initiation and tubes without crush initiator. Overall, the effect of location and number of crush initiation proved significantly influences the initial peak forces while maintain the energy absorbed.

Impact Response of Circular Tube with Concentric Plunger

2013 ◽  
Vol 275-277 ◽  
pp. 792-798
Author(s):  
Amir Radzi Ab Ghani ◽  
Hafizi Lukman ◽  
Hafizan Hashim
Keyword(s):  
Energy Absorption ◽  
Circular Tube ◽  
High Energy ◽  
Absorption Capacity ◽  
Peak Force ◽  
Impact Response ◽  
Impact Performance ◽  
High Energy Absorption ◽  
The Impact ◽  
Initial Peak

Thin-walled tubes are generally used as impact energy absorber in various application due to their ease of fabrication and installation, high energy absorption capacity and long stroke. However, the main drawback of plain tube is the high initial peak force. A concentric plunger in the form of tapered block is proposed to overcome this shortcoming while at the same time, improving the impact performance. Static and dynamic axial crushing were performed to determine the initial peak force (IPF), crush force efficiency (CFE) and specific energy absorption (SEA) for the concentric plunger with various taper angles. It was found that the concentric plunger affected the tube impact response. Comparison with plain circular tube was carried out and it was found that the concentric plunger improved the impact response of the tube especially in term of initial peak force.

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.

The Energy Absorption Behavior of Cruciforms Designed by Kirigami Approach

2018 ◽  
Vol 85 (12) ◽  
Author(s):  
Caihua Zhou ◽  
Shizhao Ming ◽  
Tong Li ◽  
Bo Wang ◽  
Mingfa Ren
Keyword(s):  
Numerical Simulations ◽  
Progressive Collapse ◽  
Offshore Structures ◽  
Peak Force ◽  
Geometric Imperfection ◽  
Single Plate ◽  
Energy Absorbers ◽  
Collapse Behavior ◽  
Parametric Analyses ◽  
Initial Peak

The cruciforms are widely employed as energy absorbers in ships and offshore structures, or basic components in sandwich panel and multicell structure. The kirigami approach is adopted in the design of cruciform in this paper for the following reasons. First, the manufacture process is simplified. Second, it can alter the stiffness distribution of a structure to trigger desirable progressive collapse modes (PCMs). Third, the kirigami pattern can be referred as a type of geometric imperfection to lower the initial peak force during impact. Experiments and numerical simulations were carried out to validate the effectiveness of kirigami approach for cruciform designs. Numerical simulations were carried out to perform comparative and parametric analyses. The comparative studies among single plate (SP), single plate with kirigami pattern (SPKP), and kirigami cruciform (KC) show that the normalized mean crushing force of KC is nearly two times higher than those of SP and SPKP, whereas the normalized initial peak force of KC reduces by about 20%. In addition, the parametric analyses suggest that both the parameters controlling the overall size (i.e., the global slenderness and local slenderness) and those related to the kirigami pattern (i.e., the length ratio and the relative position ratio) could significantly affect the collapse behavior of the cruciforms.

scholarly journals Response and Energy Absorption of Concrete Honeycombs Subjected to Dynamic In-Plane Compression: A Numerical Approach

Symmetry ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 175
Author(s):  
Wenjing Shen ◽  
Hongyuan Zhou ◽  
Xuejian Zhang ◽  
Xiaojuan Wang
Keyword(s):  
Energy Absorption ◽  
Progressive Collapse ◽  
Numerical Approach ◽  
Absorption Capacity ◽  
Foam Concrete ◽  
Stress Plateau ◽  
Collapse Mode ◽  
Particle Hydrodynamics ◽  
Plane Compression ◽  
Response Modes

Foam concrete exhibits long stress plateau with increasing strain subjected to compression and absorbs a considerable amount of energy, making them promising for building and structure protection. In the present study, hexagonal concrete honeycombs are employed to approximately represent foam concrete, whose response and energy absorption subjected to dynamic in-plane compression are investigated with smooth particle hydrodynamics method. The response modes under low to high velocity crushing are numerically investigated, with which the critical velocity separating quasi-static response and progressive collapse mode is determined. Furthermore, the dynamic energy absorption capacity is examined and discussed.

Experimental and numerical study on the crashworthiness evaluation of an intercity coach under frontal impact conditions

2020 ◽  
Vol 234 (13) ◽  
pp. 3026-3041 ◽  
Author(s):  
Mehmet Ali Güler ◽  
Muhammed Emin Cerit ◽  
Sinem Kocaoglan Mert ◽  
Erdem Acar
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Numerical Study ◽  
Absorption Capacity ◽  
The Body ◽  
Steering Wheel ◽  
Energy Absorption Capacity ◽  
Bus Structure ◽  
Bus Body ◽  
Absorption Characteristics

In this study, the energy absorption capacity of a front body of a bus during a frontal crash was investigated. The strength of the bus structure was examined by considering the ECE-R29 European regulation requirements. The nonlinear explicit finite element code LS-DYNA was used for the crash analyses. First, the baseline bus structures without any improvements were analyzed and the weak parts of the front end structure of the bus body were examined. Experimental tests are conducted to validate the finite element model. In the second stage, the bus structure was redesigned in order to strengthen the frontal body. Finally, the redesigned bus structure was compared with the baseline model to meet the requirements for ECE-R29. In addition to the redesign performed on the body, energy absorption capacity was increased by additional energy absorbers employed in the front of bus structure. This study experimentally and numerically investigated the energy absorption characteristics of a steering wheel armature in contact with a deformable mannequin during a crash. Variations in the location of impact on the armature, armature orientation, and mannequin were investigated to determine the effects of the energy absorption characteristics of the two contacting entities.

scholarly journals A Cylindrical Crash Absorber with Discontinuous Protrusions and Its Manufacture Using a Successive Partial Rubber-Bulging Method

2021 ◽  
Vol 11 (22) ◽  
pp. 10892
Author(s):  
Di Liang ◽  
Wenhao Xu ◽  
Jieliang Feng ◽  
Wei Zhao ◽  
Naoki Kawada ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Peak Load ◽  
Cylindrical Tube ◽  
Plastic Forming ◽  
Absorption Performance ◽  
The Impact ◽  
Multiple Particle ◽  
Initial Peak ◽  
Absorption Characteristics

In an effort to improve impact energy-absorption characteristics, this study introduces a cylindrical crash absorber (CAP) with discontinuous protrusions and a continuous local-expansion plastic-forming method for its manufacture. The mechanical properties of the cylindrical energy-absorption structure were modified by installing multiple particle protrusions on the cylinder sidewall to reduce the initial pickup load and improve the impact energy-absorption performance. To facilitate manufacture of the proposed CAP, a cylindrical rubber piece was placed into a cylindrical tube and pressure was applied to the rubber from both ends of the tube. The CAP was formed by the bulging force of the rubber. The formability was verified by developing a successive local bulge-forming experimental device and comparing the manufactured CAP with the results of numerical simulations. Testing of quasi-static collapse conducted on a CAP manufactured using this device verified the effectiveness of the proposed CAP design and its plastic-forming method. It was determined that this design reduced the initial peak load, and the crash absorber could maintain stability over a long, continuous distance during crushing deformation.

scholarly journals Quasi-static axial crushing of hexagonal origami crash boxes as energy absorption devices

2019 ◽  
Vol 10 (1) ◽  
pp. 133-143 ◽  
Author(s):  
Jiayao Ma ◽  
Huaping Dai ◽  
Mengyan Shi ◽  
Lin Yuan ◽  
Yan Chen ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Reasonable Agreement ◽  
Low Cost ◽  
Absorption Efficiency ◽  
Numerical Results ◽  
Peak Force ◽  
Axial Crushing ◽  
Energy Absorption Efficiency ◽  
Absorption Performance ◽  
Initial Peak

Abstract. Thin-walled tubes are widely used as energy absorption devices for their low cost and high manufacturability. Introduction of the origami technique enables the tube to follow a pre-determined failure mode and to improve its energy absorption efficiency. This paper examines the energy absorption characteristics of the origami crash box under quasi-static axial crushing. Both experimental and numerical results show that the origami pattern develops a diamond-shaped mode, bringing a reduction in initial peak force and a significant increase in energy absorption compared to the conventional hexagonal tube. The sensitivity of its energy absorption performance to various parameters is studied, and it is shown to achieve 68.29 % increase in the specific energy absorption and 13.91 % reduction in the initial peak force in the optimal case. Furthermore, an analytical solution is presented for the energy absorption, which achieves reasonable agreement with the numerical results.

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