Investigation on crushing behavior of laminated conical absorbers with different arrangements under axial loading

2019 ◽  
Vol 234 (3) ◽  
pp. 394-407
Author(s):  
Ali Akhavan Attar ◽  
Mahdi Kazemi
Keyword(s):  
Cross Sections ◽  
Peak Load ◽  
Axial Loading ◽  
Numerical Data ◽  
Experimental Tests ◽  
Finite Element Method Simulation ◽  
Absorption Capacity ◽  
Layer Arrangement ◽  
Number Of Layers ◽  
Crushing Behavior

Abstracts In this paper, the crushing properties of conical tubes made of stainless steel 430 have been investigated with different arrangements under quasi-static axial load both experimentally and numerically. For numerical investigation, nonlinear finite element method simulation is conducted using LS-Dyna software. In the experimental tests, the specimens with the height, major diameter, minor diameter and thickness of 150, 70, 50 and 1 mm are considered, respectively. Different combinations of layers are prepared using different cross-sections. A total of seven different arrangements have been designed in three distinct groups with constant mass and the crushing behavior has been extracted for them. To ensure the validity of the simulation results, several specimens which have the thickness of 1 mm have been tested experimentally. Comparing the results indicates the consistency of the experimental and numerical data. According to the obtained results, it is observed that with increasing the number of layers, the energy absorption capacity is increased; moreover, the peak load is increased by 75.2%. In fact, with increasing the number of layers, increasing trend is observed in peak load, and contrary to the initial expectations, this trend is not linear. It is also observed that by changing the layer arrangement and the layer number, the mean crushing force can increase approximately three times.

Numerical Investigation of Cross-Section on Aluminum A6063 Thin-Walled Structures under Low-Velocity Impact Loading

2014 ◽  
Vol 1019 ◽  
pp. 96-102
Author(s):  
Ali Taherkhani ◽  
Ali Alavi Nia
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Cross Sections ◽  
Peak Load ◽  
Circular Cross Section ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
Crush Strength

In this study, the energy absorption capacity and crush strength of cylindrical thin-walled structures is investigated using nonlinear Finite Elements code LS-DYNA. For the thin-walled structure, Aluminum A6063 is used and its behaviour is modeled using power-law equation. In order to better investigate the performance of tubes, the simulation was also carried out on structures with other types of cross-sections such as triangle, square, rectangle, and hexagonal, and their results, namely, energy absorption, crush strength, peak load, and the displacement at the end of tubes was compared to each other. It was seen that the circular cross-section has the highest energy absorption capacity and crush strength, while they are the lowest for the triangular cross-section. It was concluded that increasing the number of sides increases the energy absorption capacity and the crush strength. On the other hand, by comparing the results between the square and rectangular cross-sections, it can be found out that eliminating the symmetry of the cross-section decreases the energy absorption capacity and the crush strength. The crush behaviour of the structure was also studied by changing the mass and the velocity of the striker, simultaneously while its total kinetic energy is kept constant. It was seen that the energy absorption of the structure is more sensitive to the striker velocity than its mass.

A Comparative Study of Obliquely Positioned Aluminium Alloy 6063 Tubes under Axial Loading

2016 ◽  
Vol 1133 ◽  
pp. 254-258
Author(s):  
Hafizan Hashim ◽  
Amir Radzi Ab Ghani ◽  
Hafizi Lukman ◽  
N.V. David
Keyword(s):  
Comparative Study ◽  
Critical Load ◽  
Peak Load ◽  
Axial Loading ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Oblique Position ◽  
Energy Absorbers ◽  
Load Angle ◽  
Initial Peak

A conventional tube is considered in oblique position when its longitudinal is oblique. However, oblique attachments vary as the tube can be a straight or angulated tube. In the present study, impact responses of different oblique positioned tubes subject to axial loading were numerically studied. Next, the best oblique arrangements were proposed that have higher critical load angle and energy absorption capacity. Results show that specimen of Top-Bottom Angulated (TBA) from horizontal is the best choice for its lowest initial peak load and mean crush load. This data therefore has great potential for further enhance the new design of energy absorbers in oblique position.

scholarly journals Experimental and numerical study of the crushing behavior of pultruded composite tube structure

2020 ◽  
Vol 40 (7) ◽  
pp. 615-627
Author(s):  
Mohd Kamal Mohd Shah ◽  
Yeo Kiam Beng ◽  
Sanjay Mohan ◽  
Mohd Nizam Husen ◽  
Irma Othman ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Composite Structures ◽  
Numerical Study ◽  
Peak Load ◽  
Absorption Capacity ◽  
Impact Loads ◽  
Energy Absorption Capacity ◽  
Crushing Behavior ◽  
Pultruded Composites

AbstractPultrusion is considered to be a cost efficient method for developing composite structures. It facilitates the fabrication of uniform cross-section products with improved fiber alignment, mechanical properties, good surface characteristics, etc. In order to ascertain the crashworthiness, the pultruded composites shall be able to resist impact loads, and in this concern, the energy absorption capacity of the pultruded composites must be explored. This article presents the experimental and numerical investigation of the crushing behavior of polyester based pultruded composite with rectangular cross section. Pultruded rectangular tubes with e-glass/polyester composites have been developed for this study. The cross-section of the tubes was developed into two triggering profiles, the uniform edge around the section and the tulip pattern. The tubes were subjected to impact loads, and the effect of these triggering profiles on the energy absorption capacity of the tubes has been investigated. The testing of all composites has been carried out at three different impact velocities (10, 20 and 45 mm/min). The results have revealed the dependence of crushing behavior of the tubes on the loading velocity and the triggered profiles. Lower peak load and high specific energy absorption (SEA) was observed in the tube with tulip pattern profile. The results obtained from the simulation have also shown consistency with the real-time experiments.

scholarly journals The Influence of the Layer Arrangement on the Distortional Post-Buckling Behavior of Open Section Beams

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3002
Author(s):  
Tomasz Kubiak ◽  
Mariusz Urbaniak ◽  
Filip Kazmierczyk
Keyword(s):  
Cross Sections ◽  
Numerical Models ◽  
Experimental Tests ◽  
Distortional Buckling ◽  
Buckling Mode ◽  
Layer Arrangement ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Buckling Behavior ◽  
Post Buckling

The paper deals with the design of the stacking sequence of layers in the laminate beams with open-cross sections in order to create the desired behavior in the post-buckling range. Laminate beams with channel and lipped channel cross-sections made of glass fiber reinforced polymer (GFRP) laminate with different layer arrangements (symmetrical and nonsymmetrical) have been considered. In case of the nonsymmetrical stacking sequences, hygro-thermally curvature stable (HTCS) laminates have been taken into account. Pure bending was assumed as the type of load. In the case of beams with open cross-sections, this load type can cause the lateral-distortional buckling mode. A parametric study was performed to analyze the influence of layer arrangement on post-buckling behavior. The finite element method was used to developed numerical models and conduct simulations. Additionally, the experimental tests of the channel section beams were performed in order to validate the developed numerical models.

scholarly journals FINITE ELEMENT MODELING OF CRASHING BEHAVIOR CONCERNING RECTANGULAR MULTI-LAYERED THIN-WALLED STRUCTURES

2017 ◽  
Vol 20 (1) ◽  
Author(s):  
VLAD ANDREI CIUBOTARIU
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
Peak Load ◽  
Numerical Data ◽  
Transportation Systems ◽  
Steel Sheets ◽  
Thin Walled Structures ◽  
Different Shapes ◽  
Thin Walled ◽  
Energy Absorbing

<p>Tubular thin-walled structures with different shapes of the cross-sections are widely used in various transportation systems as energy absorbing components to dissipate the kinetic energy during violent collisions and crashes. The aims of this paper are to obtain numerical data on the crashing of thin-walled structures made by multiple layers of steel sheets. A series of finite element calculations was carried out on four different models crashed axially in dynamic conditions by using LS_Dyna V971. The effect of the generated fold depth on the peak load and the mean crashing load of these types of structures were also examined. </p>

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.

CRUSHING MECHANISMS OF CYLINDRICAL WINDING KENAF FIBER REINFORCED COMPOSITES

2016 ◽  
Vol 78 (6) ◽  
Author(s):  
Al Emran Ismail
Keyword(s):  
Specific Energy ◽  
Compressive Loading ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Kenaf Fiber ◽  
Number Of Layers ◽  
Lack Of Information ◽  
Force Ratio ◽  
Crushing Behavior

This paper presents the crushing behavior of cylindrical kenaf fiber reinforced composites subjected to axial compressive loading. Lack of information available on the study of cylindrical composites fabricated using kenaf yarn fibers where it is wound around the cylindrical mold. There are two important parameters are used during the composite fabrications namely fiber orientations (00, 50 and 100) and number of layers (1, 2 and 3 layers). These composite tubes are crushed axially and forces versus displacement curves are recorded. Then, the specific energy absorptions and force ratios are determined. As expected, increasing the number of layers increased the specific energy absorptions but it is not significantly affected the force ratio even different fiber orientations are used. During progressive collapses, most of the failures mechanisms observe are localized buckling with large wall fragmentations.

scholarly journals The Numerical Investigation of Aluminum Foam-protected Reinforced Concrete Slabs under Blast Loading Using AUTODYN-3D

2018 ◽  
Vol 206 ◽  
pp. 01014
Author(s):  
Ahmed K. Taha ◽  
Zhengguo Gao ◽  
Dahai Huang
Keyword(s):  
Reinforced Concrete ◽  
Aluminum Foam ◽  
Steel Plate ◽  
Three Dimensional ◽  
Experimental Tests ◽  
High Energy ◽  
Absorption Capacity ◽  
Concrete Panels ◽  
Reinforced Concrete Slabs ◽  
Concrete Target

Aluminum foam is a lightweight material with high energy absorption capacity. In this study A Nonlinear three-dimensional hydrocode numerical simulation was carried out using autodyn-3d, which is an extensive code dealing with explosion problems. In this simulation, a high explosive material (comp B) is blasted against several concrete panels. The model was first validated using experimental tests carried out by Chengqing and has shown good results. Several numerical tests were carried out to study two parameters that affect the deflection of reinforced concrete panels. The parameters included are the thickness of concrete target and the thickness of steel plate. The results showed that increasing the thickness of the steel plate has an insignificant effect on the deflection of the reinforced concrete target while increasing the thickness of the concrete panel has a significant effect on the deflection of the concrete target.

scholarly journals Cooled Pads for Tilting-Pad Journal Bearings

Lubricants ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 92
Author(s):  
Steven Chatterton ◽  
Paolo Pennacchi ◽  
Andrea Vania ◽  
Phuoc Vinh Dang
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Journal Bearings ◽  
Maximum Temperature ◽  
Inlet Temperature ◽  
Oil Film ◽  
External Cooling ◽  
Tilting Pad ◽  
Tilting Pad Journal Bearings

Tilting-pad journal bearings (TPJBs) are widely installed in rotating machines owing to their high stability, but some drawbacks can be noted, such as higher cost with respect to cylindrical journal bearings and thermal issues. High temperatures in the pads correspond to low oil-film thicknesses and large thermal deformations in the pads. Therefore, the restriction of the maximum temperature of the bearing is a key aspect for oil-film bearings. The temperature reduction is generally obtained by adopting higher oil inlet flowrates or suitable oil nozzles. In this paper, the idea of using cooled pads with internal channels in which an external cooling fluid is circulated will be applied to a TPJB for the first time. The three-dimensional TEHD model of the TPJB, equipped with a cooled pad, will be introduced, and the results of the numerical simulations will be discussed. Several analyses have been performed in order to investigate the influence of cooling conditions, such as the type, flowrate, inlet temperature and number of cooled pads. Two types of pad geometry with different cross-sections of the cooling circuit, namely, circular and six-square multi-channel sections, have been compared to the reference bearing with solid pads. Simple experimental tests were performed by means of a test rig equipped with a cooled pad bearing obtained with the additive manufacturing process, thus showing the effectiveness of the solution and the agreement with the predictions.

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