Numerical Study of the Effects of Strain Rate and Cell Geometry on Dynamic Behavior of Axial Crushing Honeycomb

2016 ◽  
Vol 725 ◽  
pp. 156-161
Author(s):  
Tsutomu Umeda ◽  
Kohei Kataoka ◽  
Koji Mimura
Keyword(s):  
Strain Rate ◽  
Energy Absorption ◽  
Numerical Study ◽  
Absorption Capacity ◽  
Metal Foil ◽  
Energy Absorption Capacity ◽  
Axial Crushing ◽  
Geometric Conditions ◽  
Crushing Behavior ◽  
Adhesively Bonded Joint

The axial crushing behavior of commercial metal honeycombs was studied with laying emphasis on the effects of strain rate and geometry on its characteristics as an energy absorber. To investigate the effect of strain rate on the energy absorption capacity, the honeycombs of some metal foil materials were numerically modeled by taking the plastic deformation and failure of adhesively-bonded joint between corrugated sheets and the initial imperfection into consideration. The relationship between the enhancement of mean buckling stress and the strain rate was discussed. Furthermore, A3003 honeycomb model was examined by changing its branch angle from 30° to 180° because the geometrical dispersion will also affect the energy absorption capacity. Typical calculated results under different strain rate and geometric conditions were compared with the corresponding experimental results. It was found that the effect of strain rate on the stress – strain relation of the honeycomb structure is greatly relaxed as compared with that of the material itself. The effects of the boundary condition on the crushing behavior of irregular honeycombs were also discussed.

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 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.

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 Energy Absorption Capability of Thin-Walled Prismatic Aluminum Tubes with Spherical Indentations

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4304
Author(s):  
Miroslaw Ferdynus ◽  
Patryk Rozylo ◽  
Michal Rogala
Keyword(s):  
Aluminum Alloy ◽  
Energy Absorption ◽  
Numerical Models ◽  
Energy System ◽  
High Energy ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Numerical Tests ◽  
Thin Walled ◽  
Crushing Behavior

The paper presents the results of numerical tests of impact and energy absorption capacity of thin-walled columns, subjected to axial impact loading, made of aluminum alloy, and having a square cross-section and spherical indentations on their lateral surfaces. The numerical models were validated using an experiment that was conducted on the Instron CEAST 9350 High Energy System drop hammer. Material properties of the applied aluminum alloy were determined on the basis of a static tension test. The crushing behavior of the columns and some crashworthiness indicators were investigated. On the basis of the results of the conducted analyses, conclusions were drawn about the most beneficial design/constructional variants in terms of achieved crashworthiness parameters.

Energy-Absorbing Characteristics of the Stiffened Thin-Walled Tubes Subjected to Axial Crushing

2013 ◽  
Vol 437 ◽  
pp. 158-163
Author(s):  
Wei Liang Dai ◽  
Xu Guang Li ◽  
Qing Chun Wang
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Absorption Capacity ◽  
Test Results ◽  
Energy Absorption Capacity ◽  
Specific Energy Absorption ◽  
Axial Crushing ◽  
The Mean ◽  
Thin Walled ◽  
Energy Absorbing

Energy absorbing characteristics of the non-stiffened and stiffened single hat sections subjected to quasi-static axial crushing were experimentally investigated. First non-stiffened hat sections were axially crushed, then structures with different stiffened methods (stiffened in hat and stiffened in the plate) were tested, finally energy absorption capacities of these structures were compared. Test results showed that, for the appropriate designed stiffened tube, the mean crush force and mass specific energy absorption were increased significantly compared to the non-stiffened. Stiffened in hat section showed a little more energy absorption capacity than that stiffened in the plate, but the structure may sustain a global bending.

scholarly journals CFRP Reinforced Foam Concrete Subjected to Dynamic Compression at Medium Strain Rate

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 10 ◽  
Author(s):  
Xiaojuan Wang ◽  
Lu Liu ◽  
Wenjing Shen ◽  
Hongyuan Zhou
Keyword(s):  
Strain Rate ◽  
Energy Absorption ◽  
Dynamic Compression ◽  
Absorption Capacity ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Foam Concrete ◽  
Energy Absorption Capacity ◽  
Reinforced Polymer ◽  
Medium Strain Rate

Carbon fiber-reinforced polymer (CFRP)-confined foam concrete can be applied in structure protection, e.g., as an impact barrier of bridge piers, in which it is used as the core of the composite impact barrier. Applying CFRP to the foam concrete exterior enhances both the CFRP and the foam concrete, leading to improved compressive performance due to their interaction. In the present study, the carbon-fiber reinforced polymer (CFRP) confining effect on the response and energy absorption of foam concrete subjected to quasi-static and medium-strain-rate dynamic compression was experimentally investigated. The confinement by CFRP changed the response and failure mode of foam concrete specimens from shear in quasi-static load and splitting in dynamic load to crushing, resulting in a significant increase in the load bearing and energy absorption capacity. The composite consisting of CFRP and foam concrete was sensitive to strain rate. In particular, the CFRP–foam concrete interaction led to the remarkably improved resistance and energy absorption capacity of CFRP-confined specimens, which were significantly higher than the sum of those of standalone CFRP and foam concrete.

Effects of Strain Rate on Energy Absorption of High Strength TRIP Steel

2014 ◽  
Vol 552 ◽  
pp. 308-314
Author(s):  
Fei Xiang Yang ◽  
Chao Qun Zhu ◽  
Jun Jie Zhao ◽  
Yan Lin He ◽  
Lin Li
Keyword(s):  
Strain Rate ◽  
Energy Absorption ◽  
Trip Steel ◽  
Static Condition ◽  
Absorption Capacity ◽  
Gradual Transition ◽  
Absorption Properties ◽  
Energy Absorption Capacity ◽  
Dynamic Tension ◽  
Dp Steel

In this paper, the energy absorption properties of 600 MPa and 800MPa grade TRIP and DP steels under different strain rates were investigated. It was shown that the deformation of dynamic specimens concentrated in parallel section under quasi-static stretching, and the strain rate had nothing to do with the energy absorption of these four steel. In the dynamic tension, the TRIP steel had a better energy absorption capacity than it in the quasi-static condition. However, the energy absorption properties of DP steel were not the case. And with the increasing of the strain rate, the energy absorption of these four steel decreased. It was because that instead of “gradual transition”, the transformation of retained austenite changed to “instantaneous transition” in dynamic tension. It made the energy absorption become smaller than it in static tension. Meanwhile, the ductility and the energy absorption capacity of the DP steel were improved, which effected by the adiabatic temperature rise. Owing to suppression of plastic deformation of these steel in dynamic tension, the energy absorption capacity of these four steel decreased with the increasing of strain rate.

Uniaxial crushing of constrained tubes

2001 ◽  
Vol 215 (3) ◽  
pp. 353-364 ◽  
Author(s):  
A A Singace ◽  
H El-Sobky
Keyword(s):  
Mild Steel ◽  
Aluminium Alloy ◽  
Energy Absorption ◽  
Radial Direction ◽  
Absorption Capacity ◽  
Displacement Curve ◽  
Energy Absorption Capacity ◽  
Axial Crushing ◽  
The Mean ◽  
Load Displacement

By changing the end constraints, the behaviour of mild steel and aluminium alloy tubes of relatively low D/ t ratio, subjected to an axial crushing load, is studied. Many combinations of end constraints were produced by radially constraining one or both ends of the loaded tube outwards, inwards or in both directions. Partially constrained mild steel and aluminium tubes are found to collapse into either a pure concertina mode or a pure diamond mode, depending on the ratio D/ t and the material characteristics. Mixed concertina-diamond modes would generally result by radially constraining the tube at both ends. Constraining the tube radially outwards at one end does not significantly affect the load-displacement characteristics and the mode of collapse. However, constraining the tube radially inwards produces a different mode than that observed under outward, inward or combined outward/inward constraint. New modes of collapse have been observed under different combinations of outward and inward constraints at both ends. Fully constraining the tubes in the radial direction results in the removal of the initial overshoot in the load-displacement curve, which is responsible for the overestimation of the mean crushing load and the energy absorption capacity of tubular elements. The mode of collapse and the energy absorbed could be controlled with the proper choice of the end constraints.

Crashworthiness optimization of hierarchical hexagonal honeycombs under out-of-plane impact

2020 ◽  
pp. 095440622093910
Author(s):  
M Altin ◽  
E Acar ◽  
MA Güler
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Specific Energy ◽  
Numerical Study ◽  
Absorption Capacity ◽  
Optimization Approach ◽  
Energy Absorption Capacity ◽  
Specific Energy Absorption ◽  
Honeycomb Structures ◽  
Out Of Plane

This paper presents a numerical study of regular and hierarchical honeycomb structures subjected to out-of-plane impact loading. The specific energy absorption capacity of honeycomb structures via nonlinear explicit finite element analysis is investigated. The constructed finite element models are validated using experimental data available in the literature. The honeycomb structures are optimized by using a surrogate-based optimization approach to achieve maximum specific energy absorption capacity. Three surrogate models polynomial response surface approximations, radial basis functions, and Kriging models are used; Kriging models are found to be the most accurate. The optimum specific energy absorption value obtained for hierarchical honeycomb structures is found to be 148% greater than that of regular honeycomb structures.

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