scholarly journals Crashworthiness Design for Bionic Bumper Structures Inspired by Cattail and Bamboo

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Tao Xu ◽  
Nian Liu ◽  
Zhenglei Yu ◽  
Tianshuang Xu ◽  
Meng Zou

Many materials in nature exhibit excellent mechanical properties. In this study, we evaluated the bionic bumper structure models by using nonlinear finite element (FE) simulations for their crashworthiness under full-size impact loading. The structure contained the structural characteristics of cattail and bamboo. The results indicated that the bionic design enhances the specific energy absorption (SEA) of the bumper. The numerical results showed that the bionic cross-beam and bionic box of the bionic bumper have a significant effect on the crashworthiness of the structure. The crush deformation of bionic cross-beam and box bumper model was reduced by 33.33%, and the total weight was reduced by 44.44%. As the energy absorption capacity under lateral impact, the bionic design can be used in the future bumper body.

2013 ◽  
Vol 437 ◽  
pp. 158-163
Author(s):  
Wei Liang Dai ◽  
Xu Guang Li ◽  
Qing Chun Wang

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.


2022 ◽  
Vol 904 ◽  
pp. 17-25
Author(s):  
Bo Hao Xu ◽  
Shuai Wang ◽  
Kai Fa Zhou ◽  
Wen Yi Ma ◽  
Nan Sun

There exist some problems in the crash box and anti-collision beam sandwich structure, such as monotone deformation pattern and uneconomical energy absorption performance. In order to raise the deformation capacity and energy absorption performance of sandwich structure, centrosymmetric reentrant honeycomb (CRH) and hexagonal centrosymmetric reentrant honeycomb (HCRH) are proposed based on auxetic reentrant honeycomb (ARH) in this work. Based on HCRH, four kinds of transverse combination structures and two kinds of longitudinal combination structures are obtained. The results of specific energy absorption show that the energy absorption capacity of the angular contact homodromous combination structure (ACOC) is about 3 times that of the other three transverse combination structures. Compared with longitudinal heterodromous combination structure (LHEC), the energy absorption capacity of longitudinal homodromous combination structure (LHOC) is improved by 72.7%.


2011 ◽  
Vol 117-119 ◽  
pp. 873-875
Author(s):  
Noor Hisyam Bin Noor Mohamed ◽  
Hasmiryadie Juneh ◽  
Mahshuri Yusof

Natural fibers are now becoming a subject of interest to replace synthetic fiber as reinforcement materials where the development of natural fiber composites has been conducted in the last few decades. The objective of this research is to investigate the energy absorption capacity of banana fiber polyester composite and its specific energy absorption capacity as well. Banana fibers are extracted and cut into 10mm, 20mm and 30mm fiber length. Fabrication of rectangular bar as composite samples with different banana fiber length and fiber volume fraction (1%, 2%, and 3%) were conducted and the results are studied and analyzed. The information on energy absorption and specific energy absorption capacity are useful for applications such as automotive structures where the ability to absorb impact may save life. The increase of banana fiber content and length shows an increase of maximum load and energy absorption values for all specimens.


2019 ◽  
Vol 947 ◽  
pp. 228-235
Author(s):  
Seung Jo Lee ◽  
Jung Min Park

This study investigated the effects of the reinforcement positions and the number of shape memory alloys (SMAs) on the structural characteristics of highly intelligent hybrid fiber reinforced concrete (hereinafter, HIHFR) beams. First, tests were conducted under monotonic loading conditions. To examine such structural characteristics, the load-deflection curve relationship and crack patterns, temperature and energy absorption, temperature and displacement ductility, displacement ductility and energy absorption, and the relationship between the displacement ductility and resilience were compared and analyzed. The reinforced concrete beam (RCB) exhibited somewhat excellent values in terms of displacement ductility, but showed the lowest values in terms of strength, resilience, and energy absorption capacity. HIHFR1 exhibited the most excellent results among the test samples in terms of resilience and energy absorption capacity. Therefore, SMAs were partially substituted for the compressive, tension, and shear reinforcement of the existing RCBs. As a result, the substitution for the compressive and tension reinforcement exhibited the best results, confirming the possibility of using SMAs as a substitute for steel reinforcement.


Author(s):  
M Altin ◽  
E Acar ◽  
MA Güler

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.


2015 ◽  
Vol 778 ◽  
pp. 18-23
Author(s):  
Jing Hui Zhao ◽  
Jian Feng Wang ◽  
Tao Liu ◽  
Na Yang ◽  
Wen Jie Duan ◽  
...  

Aluminum honeycomb is a lightweight material with high strength and strong capacity of energy absorption. In order to research energy absorption characteristic of aluminum honeycomb material, quasi-static and dynamic out-of-plane compression experiments are carried out on a double-layer aluminum honeycomb impact attenuator of one FSAE racing car. Plateau stress (PS), specific load (SL), mass specific energy absorption (MSEA), volume specific energy absorption (VSEA) and other parameters of the tested aluminum honeycomb under both quasi-static and dynamic impact conditions are analyzed. The results show that the tested aluminum honeycomb impact attenuator has good energy absorption capacity to meet the collision requirements. Furthermore, under the condition of dynamic impact, the energy absorption capacity of this honeycomb improves compared with that under the condition of quasi static compression.


Author(s):  
H Geramizadeh ◽  
S Dariushi ◽  
S Jedari Salami

The current study focuses on designing the optimal three-dimensional printed sandwich structures. The main goal is to improve the energy absorption capacity of the out-of-plane honeycomb sandwich beam. The novel Beta VI and Alpha VI were designed in order to achieve this aim. In the Beta VI, the connecting curves (splines) were used instead of the four diagonal walls, while the two vertical walls remained unchanged. The Alpha VI is a step forward on the Beta VI, which was promoted by filleting all angles among the vertical walls, created arcs, and face sheets. The two offered sandwich structures have not hitherto been provided in the literature. All models were designed and simulated by the CATIA and ABAQUS, respectively. The three-dimensional printer fabricated the samples by fused deposition modeling technique. The material properties were determined under tensile, compression, and three-point bending tests. The results are carried out by two methods based on experimental tests and finite element analyses that confirmed each other. The achievements provide novel insights into the determination of the adequate number of unit cells and demonstrate the energy absorption capacity of the Beta VI and Alpha VI are 23.7% and 53.9%, respectively, higher than the out-of-plane honeycomb sandwich structures.


2021 ◽  
Vol 21 (3) ◽  
Author(s):  
S. Talebi ◽  
R. Hedayati ◽  
M. Sadighi

AbstractClosed-cell metal foams are cellular solids that show unique properties such as high strength to weight ratio, high energy absorption capacity, and low thermal conductivity. Due to being computation and cost effective, modeling the behavior of closed-cell foams using regular unit cells has attracted a lot of attention in this regard. Recent developments in additive manufacturing techniques which have made the production of rationally designed porous structures feasible has also contributed to recent increasing interest in studying the mechanical behavior of regular lattice structures. In this study, five different topologies namely Kelvin, Weaire–Phelan, rhombicuboctahedron, octahedral, and truncated cube are considered for constructing lattice structures. The effects of foam density and impact velocity on the stress–strain curves, first peak stress, and energy absorption capacity are investigated. The results showed that unit cell topology has a very significant effect on the stiffness, first peak stress, failure mode, and energy absorption capacity. Among all the unit cell types, the Kelvin unit cell demonstrated the most similar behavior to experimental test results. The Weaire–Phelan unit cell, while showing promising results in low and medium densities, demonstrated unstable behavior at high impact velocity. The lattice structures with high fractions of vertical walls (truncated cube and rhombicuboctahedron) showed higher stiffness and first peak stress values as compared to lattice structures with high ratio of oblique walls (Weaire–Phelan and Kelvin). However, as for the energy absorption capacity, other factors were important. The lattice structures with high cell wall surface area had higher energy absorption capacities as compared to lattice structures with low surface area. The results of this study are not only beneficial in determining the proper unit cell type in numerical modeling of dynamic behavior of closed-cell foams, but they are also advantageous in studying the dynamic behavior of additively manufactured lattice structures with different topologies.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 249
Author(s):  
Przemysław Rumianek ◽  
Tomasz Dobosz ◽  
Radosław Nowak ◽  
Piotr Dziewit ◽  
Andrzej Aromiński

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.


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