scholarly journals Dynamic crushing and energy absorption of regular, irregular and functionally graded cellular structures

2011 ◽  
Vol 48 (3-4) ◽  
pp. 506-516 ◽  
Author(s):  
Amin Ajdari ◽  
Hamid Nayeb-Hashemi ◽  
Ashkan Vaziri
Keyword(s):  
Energy Absorption ◽  
Functionally Graded ◽  
Cellular Structures ◽  
Dynamic Crushing

Impact Resistance and Energy Absorption of Functionally Graded Cellular Structures

2011 ◽  
Vol 69 ◽  
pp. 73-78 ◽  
Author(s):  
Xiao Kai Wang ◽  
Zhi Jun Zheng ◽  
Ji Lin Yu ◽  
Chang Feng Wang
Keyword(s):  
Energy Absorption ◽  
Impact Resistance ◽  
Functionally Graded ◽  
Cellular Structures ◽  
Stress Wave Propagation ◽  
Initial Kinetic Energy ◽  
Gradual Change ◽  
Two Dimensional ◽  
The One ◽  
The Impact

The dynamic response of functionally graded cellular structures subjected to impact of a finite mass was investigated in this paper. Compared to a cellular structure with a uniform cell size, the one with gradually changing cell sizes may improve many properties. Based on the two-dimensional random Voronoi technique, a two-dimensional topological configuration of cellular structures with a linear density-gradient in one direction was constructed by changing the cell sizes. The finite element method using ABAQUS/Explicit code was employed to investigate the energy absorption and the influence of gradient on stress wave propagation. Results show that functionally graded cellular structures studied are superior in energy absorption to the equivalent uniform cellular structures under low initial kinetic energy impacts, and the performance of such structures can be significantly improved when the density difference is enlarged. The stress levels at the impact and support ends may be reduced by introducing a gradual change of density in cellular structures when the initial impact velocity is low.

scholarly journals Dynamic response and energy absorption of functionally graded porous structures

2018 ◽  
Vol 140 ◽  
pp. 473-487 ◽  
Author(s):  
Da Chen ◽  
Sritawat Kitipornchai ◽  
Jie Yang
Keyword(s):  
Dynamic Response ◽  
Energy Absorption ◽  
Functionally Graded ◽  
Porous Structures

Fabrication of Bulk Functionally-Graded Syntactic Foams for Impact Energy Absorption

2012 ◽  
Vol 706-709 ◽  
pp. 711-716 ◽  
Author(s):  
Tadaharu Adachi ◽  
Masahiro Higuchi
Keyword(s):  
Theoretical Analysis ◽  
Energy Absorption ◽  
Functionally Graded ◽  
Fabrication Process ◽  
Syntactic Foams ◽  
Compression Tests ◽  
Matrix Resin ◽  
Local Fracture ◽  
Density Distributions ◽  
The Matrix

Function of functionally-graded (FG) foams as energy absorption material for impact was discussed on the basis of theoretical analysis, and fabrication process of the foams was proposed in the paper. The FG foams were found to be useful as impact absorber due to progressively local fracture or cushion in the theoretical analysis. Next the fabrication process of the FG foams was suggested. The graded dispersion of the micro-balloons was conducted before curing the matrix resin in the process. The density distributions in the FG foams were confirmed to be predicted by the numerical analysis on the basis of floating the micro-balloons. Finally, compression tests were carried out to evaluate mechanical properties.

An experimental investigation on mechanical performances of 3D printed lightweight ABS pipes with different cellular wall thickness

2021 ◽  
Vol 15 (2) ◽  
pp. 8169-8177
Author(s):  
Berkay Ergene ◽  
İsmet ŞEKEROĞLU ◽  
Çağın Bolat ◽  
Bekir Yalçın
Keyword(s):  
Compressive Strength ◽  
Energy Absorption ◽  
Wall Thickness ◽  
Lattice Structure ◽  
Honeycomb Structure ◽  
Cellular Structures ◽  
Compression Tests ◽  
Absorbed Energy ◽  
Great Opportunity ◽  
3D Printed

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.

Effect of Varied Layer-Content/Thickness on Ballistic Performance of a Functionally Graded Al2O3/ZrO2 Material

2018 ◽  
Vol 928 ◽  
pp. 243-248 ◽  
Author(s):  
Yu Liang Chen ◽  
Chin Yu Huang
Keyword(s):  
Energy Absorption ◽  
Ceramic Composite ◽  
Single Layer ◽  
Areal Density ◽  
Wave Impedance ◽  
Functionally Graded ◽  
Ballistic Performance ◽  
Graded Material ◽  
Stress Damage ◽  
Transmission And Reflection

This study compared the ballistic performance of alumina (Al2O3)/ zirconia (ZrO2) functionally graded material (FGM) specimens with various levels of thickness and ZrO2 content and a pure Al2O3 single-layer ceramic composite (PCM). Ballistic tests were conducted with 0.3-inch armor-piercing (AP) projectiles, and finite element code LS-DYNA was used to examine energy absorption, stress distribution, and ceramic cone failure in the specimens. The findings are as follows: First, regarding energy absorption per unit of areal density, the 5% FGMs had the highest ballistic performance, which increased by up to 8%. By contrast, the ballistic performance of the 15% FGMs declined significantly to lower than that of the PCM. Second, the capability of the ceramic cone to withstand stress damage and projectiles was significantly greater in the 5% FGMs than in the 15% FGMs. Third, the wave impedance variations increased with the ZrO2 content in each layer, thereby enhancing the interactions between impact waves and aggravating ceramic damage. Thus, the intensities of transmission and reflection waves in the 15% FGMs increased, thereby causing reductions in its ballistic performance.

scholarly journals Novel cellular materials for energy absorption applications

2020 ◽  
Author(s):  
Mohammed Mudassir ◽  
Mahmoud Mansour
Keyword(s):  
Additive Manufacturing ◽  
Energy Absorption ◽  
Metal Foams ◽  
Cellular Materials ◽  
Cellular Structures ◽  
Senior Project ◽  
Key Factor ◽  
Good Energy ◽  
To Come ◽  
Energy Absorbing

Cellular materials such as metal foams are porous, lightweight structures that exhibit good energy absorption properties. They have been used for many years in various applications including energy absorption. Traditional cellular structures do not have consistent pore sizes and their behaviors and properties such as failure mechanisms and energy absorption are not always same even within the same batch. This is a major obstacle for their applications in critical areas where consistency is required. With the popularity of additive manufacturing, new interest has garnered around fabricating metal foams using this technology. It is necessary to study the possibility of designing cellular structures with additive manufacturing and their energy absorbing behavior before any sort of commercialization for critical applications is contemplated. The primary hypothesis of this senior project is to prove that energy absorbing cellular materials can be designed. Designing in this context is much like how a car can be designed to carry a certain number of passengers. To prove this hypothesis, the paper shows that the geometry is a key factor that affects energy absorption and that is possible to design the geometry in order to obtain certain behaviors and properties as desired. Much like designing a car, it requires technical expertise, ingenuity, experience and learning curve for designing cellular structures. It is simple to come with a design, but not so much when the design in constrained by stringent requirements for energy absorption and failure behaviors. The scope was limited to the study of metal foams such as the ones made from aluminum and titanium. The primary interest has been academic rather than finding ways to commercialize it. The study has been carried out using simulation and experimental verification has been suggested for future work. Nevertheless, the numerical or simulation results show that energy absorbing cellular structures can be designed that exhibit good energy absorption comparable to traditional metal foams but perhaps with better consistency and failure behaviors. The specific energy absorption was found to be 18 kJ/kg for aluminum metal foams and 23 kJ/kg for titanium metal foams. The average crushing force has been observed to be around 70 kN for aluminum and around 190 kN for titanium. These values are within the acceptable range for most traditional metal foams under similar conditions as simulated in this paper.

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