Experimental Study of Corrugated Tubes Under Lateral Loading

2010 ◽  
Author(s):  
A. Eyvazian ◽  
M. Shakeri ◽  
M. Zarei Mahmoudabadi
Keyword(s):  
Experimental Tests ◽  
Absorption Characteristic ◽  
Lateral Compression ◽  
Lateral Direction ◽  
Static Tests ◽  
Crushing Force ◽  
Innovative Solution ◽  
Energy Absorbers ◽  
Energy Absorbing ◽  
The Impact

The protection of structures under impact loading often necessitates the need for energy absorbers; devices designed to absorb the impact energy in a controlled manner and hence, protect the structure under consideration. Thin-walled tubes are widely used as energy absorbers in various vehicles and moving parts. The objective of the present study is to investigate the energy absorption characteristic of tubes with corrugations in different geometries, in lateral direction. In order to produce corrugations, an innovative solution is introduced. Corrugations can be very easily generated on the surface of cylindrical aluminum tubes by stamping method. Corrugations with different wavelengths and amplitudes can be produced by this method. Experimental tests are conducted to study the effect of changing corrugation geometry (type and amplitude). Quasi-static tests are carried out whose results for lateral compression show that tubes with corrugation have a higher mean crushing force and this force is directly proportional to number of corrugations and their amplitude. Moreover, it is observed that corrugated tubes can absorb approximately four times more energy than tubes without corrugations, in the same size and weight. Finally, considering the experimental tests, corrugated tubes are shown to be more effective in lateral direction as an energy absorber, and they also exhibit desirable force-deflection responses which are important in the design of energy absorbing devices.

Experimental study of corrugated tubes under lateral loading

2012 ◽  
Vol 226 (2) ◽  
pp. 109-118 ◽  
Author(s):  
A Eyvazian ◽  
I Akbarzadeh ◽  
M Shakeri
Keyword(s):  
Experimental Study ◽  
Energy Absorption ◽  
Lateral Loading ◽  
Lateral Direction ◽  
Static Tests ◽  
Crushing Force ◽  
Innovative Solution ◽  
Thin Walled ◽  
Energy Absorbers ◽  
Absorption Characteristics

Thin-walled tubes are widely used as energy absorbers in various vehicles and moving parts. The objective of this study is to investigate the energy absorption characteristics of tubes with corrugations in different geometries, under lateral loading. In order to produce corrugations, an innovative solution is introduced. Quasi-static tests were conducted to study the effect of changing the corrugation geometry (type and amplitude). The results show that tubes with corrugations have a higher mean crushing force which is directly proportional to the number of corrugations and their amplitudes. Moreover, it was observed that corrugated tubes can absorb approximately four times more energy than the tubes without corrugations in the same sizes and weights. Finally, it was found that corrugated tubes are more effective in lateral direction as energy absorbers, as they present suitable force–deflection responses.

Static and dynamic response of sandwich beams with lattice and pantographic cores

2021 ◽  
pp. 109963622110338
Author(s):  
Yury Solyaev ◽  
Arseniy Babaytsev ◽  
Anastasia Ustenko ◽  
Andrey Ripetskiy ◽  
Alexander Volkov
Keyword(s):  
Mechanical Performance ◽  
Lattice Structure ◽  
Unit Length ◽  
Experimental Tests ◽  
Plane Geometry ◽  
Sandwich Beams ◽  
Static Tests ◽  
Three Point Bending ◽  
The Core ◽  
The Impact

Mechanical performance of 3d-printed polyamide sandwich beams with different type of the lattice cores is investigated. Four variants of the beams are considered, which differ in the type of connections between the elements in the lattice structure of the core. We consider the pantographic-type lattices formed by the two families of inclined beams placed with small offset and connected by stiff joints (variant 1), by hinges (variant 2) and made without joints (variant 3). The fourth type of the core has the standard plane geometry formed by the intersected beams lying in the same plane (variant 4). Experimental tests were performed for the localized indentation loading according to the three-point bending scheme with small span-to-thickness ratio. From the experiments we found that the plane geometry of variant 4 has the highest rigidity and the highest load bearing capacity in the static tests. However, other three variants of the pantographic-type cores (1–3) demonstrate the better performance under the impact loading. The impact strength of such structures are in 3.5–5 times higher than those one of variant 4 with almost the same mass per unit length. This result is validated by using numerical simulations and explained by the decrease of the stress concentration and the stress state triaxiality and also by the delocalization effects that arise in the pantographic-type cores.

Dynamic Axial Compression of Square CFRP/Aluminium Tubes

2019 ◽  
Vol 794 ◽  
pp. 202-207
Author(s):  
Rafea Dakhil Hussein ◽  
Dong Ruan ◽  
Guo Xing Lu ◽  
Jeong Whan Yoon ◽  
Zhan Yuan Gao
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Fibre Composite ◽  
Dynamic Tests ◽  
Carbon Fibre Composite ◽  
Specific Energy Absorption ◽  
Static Tests ◽  
Crushing Force ◽  
Cfrp Tubes ◽  
The Impact

Carbon fibre composite tubes have high strength to weight ratios and outstanding performance under axial crushing. In this paper, square CFRP tubes and aluminium sheet-wrapped CFRP tubes were impacted by a drop mass to investigate the effect of loading velocity on the energy absorption of CFRP/aluminium tubes. A comparison of the quasi-static and dynamic crushing behaviours of tubes was made in terms of deformation mode, peak crushing force, mean crushing force, energy absorption and specific energy absorption. The influence of the number of aluminium layers that wrapped square CFRP tubes on the crushing performance of tubes under axial impact was also examined. Experimental results manifested similar deformation modes of tubes in both quasi-static and dynamic tests. The dynamic peak crushing force was higher than the quasi-static counterpart, while mean crushing force, energy absorption and specific energy absorption were lower in dynamic tests than those in quasi-static tests. The mean crushing force and energy absorption decreased with the crushing velocity and increased with the number of aluminium layers. The impact stroke (when the force starts to drop) decreased with the number of aluminium layers.

Impact Response of Thin-Walled Tubes: A Prospective Review

2012 ◽  
Vol 165 ◽  
pp. 130-134 ◽  
Author(s):  
Fauziah Mat ◽  
K. Azwan Ismail ◽  
S. Yaacob ◽  
O. Inayatullah
Keyword(s):  
Compressive Loading ◽  
Axial Loading ◽  
Geometrical Parameters ◽  
Axial Deformation ◽  
Thin Walled Structures ◽  
Structural Applications ◽  
Thin Walled ◽  
Energy Absorbers ◽  
Energy Absorbing ◽  
The Impact

Thin-walled structures have been widely used in various structural applications asimpact energy absorbing devices. During an impact situation, thin-walled tubesdemonstrate excellent capability in absorbing greater energy through plastic deformation. In this paper, a review of thin-walled tubes as collapsible energy absorbers is presented.As a mean of improving the impact energy absorption of thin-walled tubes, the influence of geometrical parameters such as length, diameter and wall thickness on the response of thin-walled tubes under compression axial loading are briefly discussed. Several design improvements proposed by previous researchers are also presented. The scope of this review is mainly focus on axial deformation under quasi-static and dynamic compressive loading. Other deformations, such as lateral indentation, inversion and splitting are considered beyond the scope of this paper. This review is intended to assist the future development of thin-walled tubes as efficient energy absorbing elements.

Estimating Energy Absorbing Performance of Motorcycle Safety Helmet

2014 ◽  
Vol 663 ◽  
pp. 574-578 ◽  
Author(s):  
Hamzah Azhar ◽  
Aqbal Hafeez Ariffin ◽  
Solah Mohd Syazwan ◽  
Shaw Voon Wong
Keyword(s):  
Impact Test ◽  
Head Injuries ◽  
Experimental Tests ◽  
Motorcycle Safety ◽  
The Public ◽  
Centre Of Gravity ◽  
Management Capability ◽  
Energy Absorbing ◽  
Gravity Acceleration ◽  
The Impact

Motorcyclists’ fatalities are overrepresented in the national statistics for years and the figure is predicted to rise further into the year 2020. In details, head injuries have contributed approximately 60% to the records, despite the use of safety helmets. New helmets performance has been well studied and widely accepted to reduce the head injury risks to motorcyclists by way of maximizing crash energy absorption. However in-service helmets energy management capability and information are limited. Therefore, this work attempts to further explore the knowledge and seek clarification of in-service helmet energy absorbing performance by performing experimental tests relative to standards protocols. A set of in-service helmets were collected from the public through an exchange basis and impact-tested twice per sites, at 4 sites, in accordance to MS1:1996 test protocols. The main data obtained was headform centre of gravity acceleration values, in terms of g. The results indicated that energy absorbing performances of most in-service helmets were able to meet standard requirements, regardless of their service ages. A few samples, however, demonstrated out of tolerance performances especially in the successive impact test at the same sites. Appearance of microcrack in the impact foam may have contributed to these values.

Numerical and Experimental Impact Analysis of Square Crash Box Structure with Holes

2013 ◽  
Vol 393 ◽  
pp. 447-452 ◽  
Author(s):  
Tatacipta Dirgantara ◽  
Leonardo Gunawan ◽  
Ichsan Setya Putra ◽  
Sahril Afandi Sitompul ◽  
Annisa Jusuf
Keyword(s):  
Impact Analysis ◽  
Absorption Characteristic ◽  
Frontal Impact ◽  
Explicit Finite Element ◽  
Aluminum Extrusions ◽  
Crushing Force ◽  
Box Structure ◽  
The Mean ◽  
Starting Location ◽  
The Impact

Numerical and experimental study of the effects of center holes located at opposite sides on dynamic axial crushing of thin-walled square aluminum extrusions column are presented in this paper. The results showed that, by inserting the holes, the impact energy absorption characteristic in a progressive buckling can be improved as the starting location of the plastic deformation is always from holes and peak crush force can be decrease, so that the deceleration does not exceed the limit that can injure the passenger when frontal impact occurs. Here, the results of numerical simulations, conducted using an explicit finite element code, are compared with experimental results for various hole diameter. The results shows that the peak crushing force is decrease, while the mean crushing force is relatively constant.

Stability and Hopf Bifurcation of Impact Dynamics Considering Delay in a Semi-Active Energy Absorbing Suspension System

2011 ◽  
Author(s):  
Xiaomin Dong ◽  
Wei Hu ◽  
Miao Yu ◽  
Norman M. Wereley
Keyword(s):  
Hopf Bifurcation ◽  
Time Delay ◽  
Impact Velocity ◽  
Suspension System ◽  
Impact Dynamics ◽  
Ground Vehicles ◽  
Payload Mass ◽  
Energy Absorbers ◽  
Energy Absorbing ◽  
The Impact

In a crash event, such as the crash of an aircraft or the collision of two ground vehicles, the impact dynamics are a function of the impact velocity and payload mass. A typical bumper system on a ground vehicle has passive viscous energy absorbers (PVEAs) that are optimally designed for a specific impact velocity and payload, so that off-design performance may be suboptimal, and may even be unacceptable for large perturbations in sink rate and payload mass from the designed values. This is because the load-stroke profile of the energy absorbing suspension system (EASS) is passive in that spring stiffness and damping of the energy absorbers is fixed. Therefore, in this study, the PVEA in an EASS is replaced by an active or semi-active energy absorber (SAEA), and the effects of time delay in achieving controllable semi-active damping is analyzed in the context of impact dynamics. To accomplish this, a three degree-of-freedom dynamic model of an EASS is presented, and the effect of the time delay in commanding the controllable force of the EA is analyzed. The asymptotic stability and Hopf bifurcation of the trivial steady state response are analyzed for a range of time delay. A technique to stabilize the impact dynamic is developed, and it is shown that the impact dynamics can be stabilized using appropriate feedback control.

A Numerical and Experimental Study on the Energy Absorption Characteristics of Deployable Origami Tubes

2021 ◽  
Author(s):  
Zhongyuan Wo ◽  
Julia M. Raneses ◽  
Evgueni T. Filipov
Keyword(s):  
Energy Absorption ◽  
Experimental Studies ◽  
Crushing Force ◽  
Parametric Studies ◽  
Energy Absorbers ◽  
Collapse Behavior ◽  
Energy Absorbing ◽  
Impact Characteristics ◽  
Absorption Characteristics ◽  
Better Than

Abstract Energy absorption devices are widely used to mitigate damage from collisions and impact loads. Due to the inherent uncertainty of possible impact characteristics, passive energy absorbers with fixed mechanical properties are not capable of serving in versatile application scenarios. Here, we explore a deployable design concept where origami tubes can extend, lock, and are intended to absorb energy through crushing (buckling and plasticity). This system concept is unique because origami deployment can increase the crushing distance between two impacting bodies and can tune the energy absorption characteristics. We show that the stiffness, peak crushing force, and total energy absorption of the origami tubes all increase with the deployed state. We present numerical and experimental studies that investigate these tunable behaviors under both static and dynamic scenarios. The energy-absorbing performance of the deployed origami tubes is slightly better than conventional prismatic tubes in terms of total absorbed energy and peak force. When the origami tubes are only partially deployed, they exhibit a nearly-elastic collapse behavior, however, when they are locked in a more deployed configuration they can experience non-recoverable crushing with higher energy absorption. Parametric studies reveal that the geometric design of the tube can control the nonlinear relationship between energy absorption and deployment. This concept for deployable energy-absorbing origami tubes can enable future protective systems with on-demand properties for different impact scenarios.

Scale similitude rules with acceleration consistency for trains collision

2018 ◽  
Vol 232 (10) ◽  
pp. 2466-2480 ◽  
Author(s):  
Yao Yu ◽  
Guangjun Gao ◽  
Weiyuan Guan ◽  
Rong Liu
Keyword(s):  
Experimental Model ◽  
Multibody Dynamics ◽  
Initial Length ◽  
Matlab Simulation ◽  
Impact Speed ◽  
Crushing Force ◽  
Energy Absorbing ◽  
Impact Characteristics ◽  
The Impact

This paper presents the scaled similitude rule for train collision, which follows the principle of acceleration consistency. If the similarity ratios of mass and initial impact speed of cars, crushing force, and initial length of the energy absorbing structures of trains with different proportions meet the requirements of the scaled similitude rule, the impact accelerations of each are considered to be consistent. The accuracy of the scaled similitude rule was analyzed by MATLAB simulation, which is based on the multibody dynamics theory. Before the analysis, the validation of the MATLAB model was verified based on the experimental model. Then the train-to-train collisions for two eight-car train sets with different similarity ratios were tested. Finally, the scaled similitude rule presented in this paper was found to be effective when the impact characteristics of the two models were compared.

Impact of the Foamed Aluminum-Filled Structures

2010 ◽  
Vol 44-47 ◽  
pp. 372-377
Author(s):  
Zhong Guo Zhang ◽  
Yu Zhou Sun ◽  
Bin Gao
Keyword(s):  
Energy Absorption ◽  
Shell Thickness ◽  
Aluminum Foam ◽  
Load Capacity ◽  
Absorption Capacity ◽  
Steel Shell ◽  
Absorption Characteristic ◽  
Dynamic Loadings ◽  
Energy Absorbing ◽  
The Impact

The carrying capacity and energy absorption characteristic of foamed aluminum (or aluminum foam), fabricated by melt foaming technique, are limited due to the lower strength of aluminum. The typical anti-vibration energy absorbing structures are designed as foamed aluminum-filled or sandwich structures. The deformation and absorption characteristics of foamed aluminum-filled structures subjected to impact loadings are analyzed using experimental and numerical methods in this work. The analysis shows that the steel shell of the combinative structure subjected to dynamic loadings dominates during energy absorption. The energy absorption capacity and initial instability loading increase as impact velocity increase and as increasing shell thickness duo to the interaction between steel shell and aluminum foam. The impact mass within the range of 100kg influences weakly on peak instability loading. Since the steel shell is the dominating part of load capacity and energy absorption, the reasonable design, taking into account of foam density and shell thickness and taking full advantage of interaction between steel shell and aluminum foam, should be adopted to increase the energy absorption characteristic of foam-filled structures.

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