The collapse of thick-walled metal tubes with wide external grooves as controllable energy-dissipating devices

2009 ◽  
Vol 223 (11) ◽  
pp. 2465-2480 ◽  
Author(s):  
S Salehghaffari ◽  
M Tajdari ◽  
F Mokhtarnezhad
Keyword(s):  
Energy Absorption ◽  
Shock Absorber ◽  
Experimental Studies ◽  
Axial Loading ◽  
Compression Tests ◽  
Static Compression ◽  
Axial Crushing ◽  
Wide Groove ◽  
Experimental Findings ◽  
Energy Dissipating Device

This article focuses on the experimental and theoretical investigation of the axial crushing behaviour of thick-walled tubes with a number of wide grooves, cut from their outer surface, under both static and dynamic loading. While this structure is subjected to axial loading, plastic deformation occurs within the space of each wide groove, and thick portions (grooveless areas) control and stabilize the collapsing of grooved thick-walled tubes. Therefore, the kinetic energy is dissipated by the plastic collapsing of the structure between grooves. In the present study, quasi-static compression tests of specimens with various geometric parameters are performed. Dynamic tests of some specimens using a drop hammer apparatus are also carried out to study the dynamic effects on the collapsing and energy absorption behaviour of the shock absorber. Numerical simulations of axial crushing of the shock absorber under both quasi-static and impact loading, using LS-DYNA finite-element explicit code, are also carried out in this article, and their results are verified with experimental findings. Based on experimental studies, an analysis with consideration of strain hardening effects to predict mean crushing load and energy absorption of the structure under axial compression is developed. Through the performed experimental, numerical, and analytical studies, major parameters in the design of the shock absorber are characterized and possible collapse modes of deformation during axial crushing of the structure are identified. In the present study, experimental and theoretical studies show that the introduced structure can be considered as an efficient energy-dissipating device since it provides favourable crashworthiness characteristics.

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.

Experimental investigation of the quasi-static and impact tests on the energy absorption characteristics of coupler rubber buffers used in railway vehicles

2018 ◽  
Vol 233 (9) ◽  
pp. 937-950 ◽  
Author(s):  
Shuguang Yao ◽  
Zhixiang Li ◽  
Wen Ma ◽  
Ping Xu ◽  
Quanwei Che
Keyword(s):  
Energy Absorption ◽  
Impact Velocity ◽  
High Speed ◽  
Compression Tests ◽  
Static Compression ◽  
Static Tests ◽  
Impact Tests ◽  
High Speed Trains ◽  
The Impact ◽  
Absorption Characteristics

Coupler rubber buffers are widely used in high-speed trains, to dissipate the impact energy between vehicles. The rubber buffer consists of two groups of rubbers, which are pre-compressed and then installed into the frame body. This paper specifically focuses on the energy absorption characteristics of the rubber buffers. Firstly, quasi-static compression tests were carried out for one and three pairs of rubber sheets, and the relationship between the energy absorption responses, i.e. Eabn  =  n ×  Eab1, Edissn =  n ×  Ediss1, and Ean =  Ea1, was obtained. Next, a series of quasi-static tests were performed for one pair of rubber sheet to investigate the energy absorption performance with different compression ratios of the rubber buffers. Then, impact tests with five impact velocities were conducted, and the coupler knuckle was destroyed when the impact velocity was 10.807 km/h. The results of the impact tests showed that with the increase of the impact velocity, the Eab, Ediss, and Ea of the rear buffer increased significantly, but the three responses of the front buffer did not increase much. Finally, the results of the impact tests and quasi-static tests were contrastively analyzed, which showed that with the increase of the stroke, the values of Eab, Ediss, and Ea increased. However, the increasing rates of the impact tests were higher than that of the quasi-static tests. The maximum value of Ea was 68.76% in the impact tests, which was relatively a high value for the vehicle coupler buffer. The energy capacity of the rear buffer for dynamic loading was determined as 22.98 kJ.

Impact Energy Absorption of Continuous Fiber Composite Tubes

1987 ◽  
Vol 109 (1) ◽  
pp. 72-77 ◽  
Author(s):  
D. W. Schmueser ◽  
L. E. Wickliffe
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Failure Modes ◽  
Fiber Composite ◽  
Impact Testing ◽  
Compression Tests ◽  
Buckling Mode ◽  
Static Compression ◽  
Specific Energy Absorption ◽  
Fiber Splitting

This paper presents the results of an impact testing program that was conducted to characterize the energy absorption and failure characteristics of selected composite material systems and to compare the results with aluminum and steel. Composite tube specimens were constructed using graphite/epoxy (Gr/Ep), Kevlar/epoxy (K/Ep), and glass/epoxy (Gl/Ep) prepreg tape and were autoclave cured. Vertical impact and static compression tests were performed on 56 tubes. Tests results for energy absorption varied significantly as a function of lay-up angle and material type. In general, the Gr/Ep tubes had specific energy absorption values that were greater than those for K/Ep and Gl/Ep tubes having the same ply construction. Angle-ply Gr/Ep and K/Ep tubes had specific energy absorption values that were greater than those for 1024 steel tubes. Gr/Ep and Gl/Ep angle-ply tubes exhibited brittle failure modes consisting of fiber splitting and ply delamination, whereas the K/Ep angle-ply tubes collapsed in an accordian buckling mode similar to that obtained for metal tubes.

scholarly journals EXPERIMENTAL STUDIES ON THE QUASI-STATIC AXIAL CRUSHING BEHAVIOR OF FOAM-FILLED STEEL EXTRUSION TUBES

2010 ◽  
Vol 10 (1) ◽  
pp. 1-17 ◽  
Author(s):  
AL EMRAN ISMAIL
Keyword(s):  
Energy Absorption ◽  
Polyurethane Foam ◽  
Experimental Studies ◽  
Foam Density ◽  
Automotive Safety ◽  
Polymeric Foam ◽  
Axial Crushing ◽  
Head Displacement ◽  
Foam Filled ◽  
Crushing Behavior

The concerns of automotive safety have been given special attention in order to reduce human fatalities or injuries. One of the techniques to reduce collision impact or compression energy is by filling polymeric foam into metallic tubes. In this work, polyurethane foam was introduced into the steel extrusion tubes and quasi-statically compressed at constant cross-head displacement. Different tube thicknesses and foam densities were used and these parameters were related to the crashworthiness aspect of the foam-filled structures. It is found that both tube thickness and foam density played an important role in increasing the crashworthiness behaviours of the structures but when the tube thickness reached certain value, foam density unable to properly work in increasing the energy absorption of the structures.

Research on the Static Cushioning Property of Folding Corrugated Cushions

2014 ◽  
Vol 989-994 ◽  
pp. 3258-3261
Author(s):  
Yu Ming Qi ◽  
Wen Hua Gao
Keyword(s):  
Energy Absorption ◽  
Structural Parameter ◽  
Absorption Method ◽  
Compression Tests ◽  
Static Compression ◽  
Corrugated Board

0940 type cushion of E-flute corrugated paperboard is selected as the research object. By changing the load area, side breadth and the height of the cushions separately, static compression tests were done. The effects of structural parameter to cushioning property were analyzed through energy absorption method. It is useful to promote the application of corrugated board cushion.

Bi-tubular corrugated composite conical–cylindrical tube for energy absorption in axial and oblique loading: Analysis and optimization

2020 ◽  
Vol 54 (18) ◽  
pp. 2399-2432 ◽  
Author(s):  
Amirreza Sadighi ◽  
Mahshid Mahbod ◽  
Masoud Asgari
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Cylindrical Tube ◽  
Element Model ◽  
Geometrical Parameters ◽  
Compression Tests ◽  
Static Compression ◽  
Optimization Study ◽  
Crushing Force ◽  
Optimum Model

In this paper, a new bi-tubular corrugated composite tube, consisting of inner and outer cylindrical and conical tubes is proposed. Different models with various geometrical parameters including the radius of curvatures and their numbers are considered and studied numerically in axial and oblique crushing in order to achieve favorable crashworthiness parameters. Moreover, quasi-static compression tests have been conducted to obtain results in order to validate the finite element model. There has been a sensible agreement between the numerical results and experimental data. Finite element models are also validated using the analytical solutions for both straight and corrugated composite tubes. Regardless of the number and radius of curvatures, as the crashworthiness of bi-tubular corrugated structures both in axial and oblique crushing is investigated and compared with their single-wall and bi-tubular straight peers, a considerable improvement is achieved in all crashworthiness parameters, including desirable increase in specific energy absorption, favorable reduction in peak force, and consequently a beneficial rise in crushing force efficiency. In addition, an optimization study using a suitable multi-objective function is done to choose the best model among the existing models, in addition to finding an optimum model via genetic algorithm. In the next step, a parametric study is conducted on the best model to inspect how well it undergoes oblique crushing at different angles. Finally, this best model and two other candidates have been chosen to investigate the effect of using foams and then the energy absorption capability of the empty and foam-filled tubes has been compared.

AN EXPERIMENTAL STUDY ON THE BEHAVIOUR OF GLASS FILLED POLYPROPYLENE AND POLYETHYLENE COMPOSITE PIPES UNDER QUASI-STATIC AXIAL LOADING

2015 ◽  
Vol 74 (10) ◽  
Author(s):  
H. H. Ya ◽  
H. EL-Sobky
Keyword(s):  
Energy Absorption ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Axial Loading ◽  
Fibre Volume ◽  
Compression Tests ◽  
Local Fracture ◽  
Polyethylene Composite ◽  
The Difference ◽  
Composite Pipes

The behaviour of extruded glass fibre reinforced thermoplastic pipes under axial crushing load was investigated experimentally. It was envisaged that the difference between the axial and hoop moduli and strengths as well as the volume fraction would influence the mode of collapses and energy absorption. The ability to vary the moduli and the fibre volume fraction provides means of controlling the collapse mode in order to optimize specific energy absorption. Axial compression tests were performed on glass filled Polypropylene (GPP) and glass filled Polyethylene (GPE) composite pipes. The samples were chosen with a variety of fibre volume fraction (Vf = 5% to 20% and average angle of orientation 15θ">  = 50o to 80o) to evaluate the effect of anisotropy and Vf to the collapse modes when subjected to axial static loading. The results from the experiments revealed that typical axial and hoop modulus (Ea and 15Eθ"> ) of GPP and GPE pipes increased with increasing of 15θ">  from 55 15°">  to 75 15°">  and decreased gradually in between 75 15°">  to 80 15°"> . The axial modulus was increased constantly with the increase of Vf from 5 % to 20 %. However, the hoop modulus is the highest at 5% Vf, decreases significantly at 10%, and gradually increases at 20%. It is noticed that, the GPP and GPE pipes contain higher Vf and 15θ"> , collapsed in brittle failure mode (fragmentation), whereas those with less Vf and 15θ">  angle, collapsed in non-axis-symmetric (diamond) mode with the local fracture while the local fracture disappeared with lower fibre contents.

scholarly journals Compressive Properties of Functionally Graded Bionic Bamboo Lattice Structures Fabricated by FDM

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4410
Author(s):  
Zhou Wen ◽  
Ming Li
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Honeycomb Structure ◽  
Absorption Capacity ◽  
Functionally Graded ◽  
Honeycomb Lattice ◽  
Lattice Structures ◽  
Compression Tests ◽  
Uniform Lattice ◽  
Static Compression

Bionic design is considered a promising approach to improve the performance of lattice structures. In this work, bamboo-inspired cubic and honeycomb lattice structures with graded strut diameters were designed and manufactured by 3D printing. Uniform lattice structures were also designed and fabricated for comparison. Quasi-static compression tests were conducted on lattice structures, and the effects of the unit cell and structure on the mechanical properties, energy absorption and deformation mode were investigated. Results indicated that the new bionic bamboo structure showed similar mechanical properties and energy absorption capacity to the honeycomb structure but performed better than the cubic structure. Compared with the uniform lattice structures, the functionally graded lattice structures showed better performance in terms of initial peak strength, compressive modulus and energy absorption.

scholarly journals Research on Static Compression Test of Polyurethane Foam/Honeycomb Paperboard Composite Material

2015 ◽  
Vol 9 (1) ◽  
pp. 64-70
Author(s):  
Wang Ju ◽  
Liang Jifeng ◽  
Lv Lei
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Mechanical Behavior ◽  
Energy Absorption ◽  
Polyurethane Foam ◽  
Compression Test ◽  
Testing Machine ◽  
Compression Tests ◽  
Static Compression ◽  
Simple Materials

To study the mechanical behavior and energy absorption ability of polyurethane foam/honeycomb paperboard composite material under the static compression test. The static compression tests of polyurethane foam/honeycomb paperboard composite material are conducted by electronic universal testing machine. The mechanical behavior under the condition of static compression and the factors influencing the composite materials’ static cushioning properties were analyzed. Then, a comparison was made based on the energy absorption ability between composite materials and simple materials. The yield stress, strength and other indicators of foam/honeycomb paperboard have doubled the growth after filling polyurethane. The aperture size is the main influencing factor affecting the static cushioning properties of composite material. The energy absorption amount of composite materials is about 1.85 times than the total energy of two simple materials.

scholarly journals A Novel Bionic Structure Inspired by Luffa Sponge and Its Cushion Properties

2020 ◽  
Vol 10 (7) ◽  
pp. 2584 ◽  
Author(s):  
Yong Xie ◽  
Hailong Bai ◽  
Zhenghao Liu ◽  
Nanning Chen
Keyword(s):  
Energy Absorption ◽  
Optimization Design ◽  
Fractal Theory ◽  
Compression Tests ◽  
Element Analysis ◽  
Static Compression ◽  
Bionic Structure ◽  
Best Parameter ◽  
Python Programming ◽  
Luffa Sponge

The luffa sponge shows excellent cushion properties. This paper presents a bio-inspired structure of the luffa sponge. The geometry of the bionic structure was built based on the fractal theory by Python programming language and prepared by a 3D printer. Then a series of quasi-static compression tests and finite element analysis were carried out to determine the cushion properties. An optimization design was adopted to determine the best design parameter. The results showed that the influence of length ( a ) on specific energy absorption was more important than the degree ( θ ). The best parameter was found to be length less than 4 mm and angle around 11 degrees. The bionic structure of luffa sponge may show a novel perspective on natural cellular material. The findings demonstrate the great potential for designing hierarchical cellular structures and broad application prospects in the field of cushioning and energy absorption.

Sign in / Sign up

Export Citation Format

Share Document