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.

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.

Attempts to improve energy absorption characteristics of circular metal tubes subjected to axial loading

2010 ◽  
Vol 48 (6) ◽  
pp. 379-390 ◽  
Author(s):  
S. Salehghaffari ◽  
M. Tajdari ◽  
M. Panahi ◽  
F. Mokhtarnezhad
Keyword(s):  
Energy Absorption ◽  
Axial Loading ◽  
Absorption Characteristics

Effects of Wall Thickness and Crush Initiators Position under Experimental Drop Test on Square Tubes

2017 ◽  
Vol 865 ◽  
pp. 612-618 ◽  
Author(s):  
M. Malawat ◽  
Jos Istiyanto ◽  
D.A. Sumarsono
Keyword(s):  
Energy Absorption ◽  
Tube Wall ◽  
Impact Load ◽  
Peak Load ◽  
Load Force ◽  
Drop Height ◽  
Thin Walled ◽  
The Impact ◽  
Initial Peak ◽  
Load Mass

Crush initiators are the weakest points to reduce initial peak load force with significant energy absorption ability. The objective of this paper is to study the effects of square tube thickness and crush initiators position for impact energy absorber (IEA) performance on thin-walled square tubes. Two square tubes having thickness about 0.6 mm (specimen code A) and 1 mm (specimen Code C) were tested under dynamic load. The crushing initiator is designed around the shape of the tube wall and has eight holes with a fixed diameter of 6.5 mm. In the experiment, the crushing initiator was determined at 5 different locations on the specimen wall. These locations are 10 mm, 20 mm. 30 mm, 40 mm, and 50 mm measured from the initial collision position of the specimen tested. The impact load mass was about 80 kg and had a drop height of about 1.5 m. Using the simulation program of the LabVIEW Professional Development System 2011 and National Instrument (NI) 9234 software equipped with data acquisition hardware NI cDAQ-9174 the signal from the load cell was sent to a computer. By controlling the thickness of the thin-walled square tube, the peak loading force can be decreased by approximately 56.75% and energy absorption ability of IEA can be increased approximately to 11.83%. By using different thin-walled square tube can produce different best crush initiators position with the lowest peak load force.

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.

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 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.

Efficient crushable corrugated conical tubes for energy absorption considering axial and oblique loading

2018 ◽  
Vol 233 (11) ◽  
pp. 3917-3935 ◽  
Author(s):  
Alireza Ahmadi ◽  
Masoud Asgari
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Specific Energy ◽  
Axial Loading ◽  
Element Model ◽  
Compression Tests ◽  
Static Compression ◽  
Specific Energy Absorption ◽  
Thin Walled Structures ◽  
Absorption Characteristics

Thin-walled structures are of much interest as energy absorption devices for their great crashworthiness and also low weight. Conical tubes are favorable structures because unlike most other geometries, they are also useful in oblique impacts. This paper investigated the effect of corrugations on energy absorption characteristics of conical tubes under quasi-static axial and oblique loadings. To do so, conical tubes with different corrugation geometries were analyzed using the finite element explicit code and the effects of corrugations on initial peak crushing force and specific energy absorption were studied. The finite element model was validated by experimental quasi-static compression tests on simple and corrugated aluminum cylinders. An efficient analytical solution for EA during axial loading was also derived and compared with the FEM solution. The crushing stableness was analyzed using the undulation of the load-carrying capacity parameter and it was shown that corrugations made collapsing mode, more predictable and controllable. The findings have shown that corrugated conical tubes have much better energy absorption characteristics compared with their non-corrugated counterparts. It was also discovered that during oblique loadings, introducing corrugations can significantly increase the specific energy absorption compared with simple cones.

Axial Crushing of Thin-Walled Tubes With Kite-Shape Pattern

2015 ◽  
Author(s):  
Degao Hou ◽  
Yan Chen ◽  
Jiayao Ma ◽  
Zhong You
Keyword(s):  
Energy Absorption ◽  
Peak Force ◽  
Great Promise ◽  
Axial Crushing ◽  
Crushing Force ◽  
Collapse Mode ◽  
Shape Pattern ◽  
The Mean ◽  
Thin Walled ◽  
Initial Peak

Thin-walled tubes are widely used as energy absorption devices in automobiles, designed to protect the costly structures and people inside during an impact event through plastic deformation. They show excellent performance under axial loading in terms of weight efficiency, stroke distance and total energy absorption, but also have the disadvantage that the crushing force is not uniform during deformation process, especially with the existence of a high initial peak force. Recently, pattern design on tubular structures has received increasing attention. It has been found that, if the surface of a tube is pre-folded according to an origami pattern, the collapse mode of the tube can be altered, leading to changes in energy absorption performance. In this paper, we present a series of origami patterned tubes with a kite-shape pattern that is constructed by joining two pieces of Miura-ori. First of all, the geometry of the pattern is presented. We develop a theoretical model to predict the energy absorption associated with the axial crushing of the patterned tubes and derive a mathematical formula to calculate the mean crushing force accordingly. Secondly, a family of origami tubes with various profiles are designed, and their performances subjected to quasi-static axial crushing are numerically investigated. A parametric study is also conducted to establish the relationship between the pre-folded angle of the pattern and the initial peak force as well as the mean crushing force. Numerical results show that introducing patterns to thin-walled tubes offers three advantages in comparison with conventional tubes, i.e., a lower initial peak force, a more uniform crushing load, and a stable and repeatable collapse mode. A 36.0% increase in specific energy absorption and 67.2% reduction in initial peak force is achieved in the optimum case. The new origami patterned tubes show great promise as energy absorption devices.

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