Design of Honeycomb Mesostructures for Crushing Energy Absorption

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Jesse Schultz ◽  
David Griese ◽  
Jaehyung Ju ◽  
Prabhu Shankar ◽  
Joshua D. Summers ◽  
...  

This paper presents the energy absorption properties of hexagonal honeycomb structures of varying cellular geometries under high speed in-plane crushing. While the crushing responses in terms of energy absorption and densification strains have been extensively researched and reported, a gap is identified in the generalization of honeycombs with contr’olled and varying geometric parameters. This paper addresses this gap through a series of finite element (FE) simulations where the cell angle and the inclined wall thickness, are varied while maintaining a constant mass of the honeycomb structure. A randomly filled, nonrepeating design of experiments (DOEs) is generated to determine the effects of these geometric parameters on the output of energy absorbed and a statistical sensitivity analysis is used to determine the parameters significant for the crushing energy absorption of honeycombs. It is found that while an increase in the inclined wall thickness enhances the energy absorption of the structure, increases in either the cell angle or ratio of cell angle to inclined wall thickness have adverse effects on the output. Finally, the optimization results suggest that a cellular geometry with a positive cell angle and a high inclined wall thickness provides for maximum energy absorption, which is verified with a 6% error when compared to a FE simulation.

Author(s):  
Jesse Schultz ◽  
David Griese ◽  
Prabhu Shankar ◽  
Joshua D. Summers ◽  
Jaehyung Ju ◽  
...  

This paper presents the energy absorption properties of hexagonal honeycomb structures of varying cellular geometries to high speed in-plane impact. While the impact responses in terms of energy absorption and densification strains have been extensively researched and reported, a gap is identified in the generalization of honeycombs with controlled and varying geometric parameters. This paper attempts to address this gap through a series of finite element (FE) simulations where cell angle and angled wall thickness are varied while maintaining a constant mass of the honeycomb structure. A randomly filled, non-repeating Design of Experiments (DOE) is generated to determine the effects of these geometric parameters on the output of energy absorbed, and a statistical sensitivity analysis is used to determine the parameters significant for optimization. A high degree of variation in the impact response of varying cellular geometries has shown the potential for the forward design into lightweight crushing regions in many applications, particularly the automotive and aerospace industries. It is found that while an increase in angled wall thickness enhances the energy absorption of the structure, increases in either the cell angle or ratio of cell angle to angled wall thickness have adverse effects on the output. Finally, optimization results present that a slightly auxetic cellular geometry with maximum angled wall thickness provides for maximum energy absorption, which is verified with an 8% error when compared to a final FE simulation.


2021 ◽  
Vol 15 (2) ◽  
pp. 8169-8177
Author(s):  
Berkay Ergene ◽  
İsmet ŞEKEROĞLU ◽  
Çağın Bolat ◽  
Bekir Yalçın

In recent years, cellular structures have attracted great deal of attention of many researchers due to their unique properties like exhibiting high strength at low density and great energy absorption. Also, the applications of cellular structures (or lattice structures) such as wing airfoil, tire, fiber and implant, are mainly used in aerospace, automotive, textile and biomedical industries respectively. In this investigation, the idea of using cellular structures in pipes made of acrylonitrile butadiene styrene (ABS) material was focused on and four different pipe types were designed as honeycomb structure model, straight rib pattern model, hybrid version of the first two models and fully solid model. Subsequently, these models were 3D printed by using FDM method and these lightweight pipes were subjected to compression tests in order to obtain stress-strain curves of these structures. Mechanical properties of lightweight pipes like elasticity modulus, specific modulus, compressive strength, specific compressive strength, absorbed energy and specific absorbed energy were calculated and compared to each other. Moreover, deformation modes were recorded during all compression tests and reported as well. The results showed that pipe models including lattice wall thickness could be preferred for the applications which don’t require too high compressive strength and their specific energy absorption values were notably capable to compete with fully solid pipe structures. In particular, rib shape lattice structure had the highest elongation while the fully solid one possessed worst ductility. Lastly, it is pointed out that 3D printing method provides a great opportunity to have a foresight about production of uncommon parts by prototyping.


2010 ◽  
Vol 160-162 ◽  
pp. 1488-1493
Author(s):  
Dong Mei Wang ◽  
Qiang Hua Liao ◽  
Zi You Bai

Many experiments and analysis of folded honeycomb consisting of corrugated paperboards show that the use of linerboard can increase the energy absorption and weight of folded honeycombs. However, it reduces the energy absorption per unit volume and unit mass and increases the cushioning cost either. For the same corrugate shape, reducing corrugated size will increase the weight of folded honeycombs, and changing corrugated size will change the energy absorption per unit volume, but it can not change the cushioning cost. At a low relative density of corrugated sandwiches, the energy absorption per unit volume and unit mass rapidly increases, and the cushioning cost decreases when the relative density of corrugated sandwiches rises. While at a higher relative density, the energy absorption per unit volume and unit mass does not effectively increase with relative density of corrugated sandwiches. However, the cushioning cost may increases. Therefore, when designing the corrugated sandwich size, we can change the thickness of corrugate basis-paper or the corrugated size to change the relative density of corrugated sandwiches and the cushioning cost.


Author(s):  
Leo de Waal ◽  
Zhong You

Abstract When loaded parallel to the prismatic cells (out-of-plane), honeycombs and re-entrant honeycombs exhibit high initial stiffness and peak force, followed by a force reduction as progressive failure occurs. The high initial peak force and large post-peak force reduction are undesirable for energy absorption purposes. In this study a graded honeycomb structure based on origami is proposed in an effort to lower the peak force, increase the energy absorption capacity and tune the stiffness throughout the loading process. The grading is achieved through a developable origami crease pattern that utilises the typical honeycomb expansion manufacturing technique. The crease pattern has one degree of freedom and is constructed from a repetition of a modified Miura-ori unit. A kinematic study of the crease pattern is completed, highlighting the simple geometric parameters that can be altered to tune the structure. Quasi-static numerical simulations are then used to investigate the interaction between these simple geometric parameters, the energy absorption capacity and the stiffness throughout the loading process. Compared to honeycomb and re-entrant honeycomb tubes, it has been found that a reduction in the peak force, increase in energy absorption capacity and tunable stiffness can be achieved.


Author(s):  
S. Jenson ◽  
M. Ali ◽  
K. Alam ◽  
J. Hoffman

The work presented here is a continuation of the study performed in exploring the energy absorption characteristics of non-Newtonian fluid-filled regular hexagonal aluminum honeycomb structures. In the previous study, energy absorbing properties were investigated by using an air powered pneumatic ram, dynamic load cell, and a high speed camera. This study was conducted using a pneumatic ram which was designed to exploit only its kinetic energy during the impact. Experimental samples included an empty honeycomb sample and a filled sample as the filled samples showed the largest difference in energy absorption with respect to the empty samples in the previous study. Therefore, the filled samples were further investigated in this study by measuring the impact forces at the distal end as well as the damage on the impact end. Upon impact, the filled samples were able to reduce the damage area on impact end and were able to lower average and peak forces by 71.9% and 77.4% at the distal end as compared to the empty sample.


2021 ◽  
Vol 11 (12) ◽  
pp. 5445
Author(s):  
Shengyong Gan ◽  
Xingbo Fang ◽  
Xiaohui Wei

The aim of this paper is to obtain the strut friction–touchdown performance relation for designing the parameters involving the strut friction of the landing gear in a light aircraft. The numerical model of the landing gear is validated by drop test of single half-axle landing gear, which is used to obtain the energy absorption properties of strut friction in the landing process. Parametric studies are conducted using the response surface method. Based on the design of the experiment results and response surface functions, the sensitivity analysis of the design variables is implemented. Furthermore, a multi-objective optimization is carried out for good touchdown performance. The results show that the proportion of energy absorption of friction load accounts for more than 35% of the total landing impact energy. The response surface model characterizes well for the landing response, with a minimum fitting accuracy of 99.52%. The most sensitive variables for the four landing responses are the lower bearing width and the wheel moment of inertia. Moreover, the max overloading of sprung mass in LC-1 decreases by 4.84% after design optimization, which illustrates that the method of analysis and optimization on the strut friction of landing gear is efficient for improving the aircraft touchdown performance.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1602
Author(s):  
Ángel Molina-Viedma ◽  
Elías López-Alba ◽  
Luis Felipe-Sesé ◽  
Francisco Díaz

Experimental characterization and validation of skin components in aircraft entails multiple evaluations (structural, aerodynamic, acoustic, etc.) and expensive campaigns. They require different rigs and equipment to perform the necessary tests. Two of the main dynamic characterizations include the energy absorption under impact forcing and the identification of modal parameters through the vibration response under any broadband excitation, which also includes impacts. This work exploits the response of a stiffened aircraft composite panel submitted to a multi-impact excitation, which is intended for impact and energy absorption analysis. Based on the high stiffness of composite materials, the study worked under the assumption that the global response to the multi-impact excitation is linear with small strains, neglecting the nonlinear behavior produced by local damage generation. Then, modal identification could be performed. The vibration after the impact was measured by high-speed 3D digital image correlation and employed for full-field operational modal analysis. Multiple modes were characterized in a wide spectrum, exploiting the advantages of the full-field noninvasive techniques. These results described a consistent modal behavior of the panel along with good indicators of mode separation given by the auto modal assurance criterion (Auto-MAC). Hence, it illustrates the possibility of performing these dynamic characterizations in a single test, offering additional information while reducing time and investment during the validation of these structures.


Author(s):  
Shi Hu ◽  
Huaming Tang ◽  
Shenyao Han

AbstractIn this paper, polyvinyl chloride (PVC) coarse aggregate with different mixing contents is used to solve the problems of plastic pollution, low energy absorption capacity and poor damage integrity, which provides an important reference for PVC plastic concrete used in the initial support structures of highway tunnels and coal mine roadway. At the same time, the energy absorption characteristics and their relationship under different impact loads are studied, which provides an important reference for predicting the energy absorption characteristics of concrete under other PVC aggregate content or higher impact speed. This study replaced natural coarse aggregate in concrete with different contents and equal volume of well-graded flaky PVC particles obtained by crushing PVC soft board. Also, slump, compression, and splitting strength tests, a free falling low-speed impact test of steel balls and a high-speed impact compression test of split Hopkinson pressure bar (SHPB) were carried out. Results demonstrate that the static and dynamic compressive strength decreases substantially, and the elastic modulus and slump decrease slowly with the increase of the mixing amount of PVC aggregate (0–30%). However, the energy absorption rate under low-speed impact and the specific energy absorption per MPa under high-speed impact increase obviously, indicating that the energy absorption capacity is significantly enhanced. Regardless of the mixing amount of PVC aggregate, greater strain rate can significantly enhance the dynamic compressive strength and the specific energy absorption per MPa. After the uniaxial compression test or the SHPB impact test, the relative integrity of the specimen is positively correlated with the mixing amount of PVC aggregate. In addition, the specimens are seriously damaged with the increase of the impact strain rate. When the PVC aggregate content is 20%, the compressive strength and splitting strength of concrete are 33.8 MPa and 3.26 MPa, respectively, the slump is 165 mm, the energy absorption rate under low-speed impact is 89.5%, the dynamic compressive strength under 0.65 Mpa impact air pressure is 58.77 mpa, and the specific energy absorption value per MPa is 13.33, which meets the requirements of shotcrete used in tunnel, roadway support and other impact loads. There is a linear relationship between the energy absorption characteristics under low-speed impact and high-speed impact. The greater the impact pressure, the larger the slope of the fitting straight line. The slope and intercept of the fitting line also show a good linear relationship with the increase of impact pressure. The conclusions can be used to predict the energy absorption characteristics under different PVC aggregate content or higher-speed impact pressure, which can provide important reference for safer, more economical, and environmental protection engineering structure design.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaoqin Hao ◽  
Jia Yu ◽  
Weidong He ◽  
Yi Jiang

To solve the problem of the effective cushioning of fast-moving mechanical components in small ring-shaped spaces, the factors affecting the compression and energy absorption properties of small-sized hollow metal tubes were studied. Simulation models were constructed to analyse the influences of tube diameter, wall thickness, relative position, and number of stacked components on the compression and energy absorption properties. The correctness of the simulation method and its output were verified by experiments, which proved the effectiveness of compression and energy absorption properties of small-sized thin-walled metal tubes. The research provides support for the application of metal tube buffers in armament launch technology and engineering practice.


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