scholarly journals A Multi-Cell Hybrid Approach to Elevate the Energy Absorption of Micro-Lattice Materials

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4083
Author(s):  
Lijun Xiao ◽  
Xiao Xu ◽  
Weidong Song ◽  
Menglei Hu
Keyword(s):  
Energy Absorption ◽  
Cell Hybrid ◽  
Volume Fraction ◽  
Hybrid Approach ◽  
Symmetric Distribution ◽  
Soft Matrix ◽  
Plastic Energy ◽  
Bcc Lattice ◽  
Lattice Materials ◽  
Absorption Performance

Multi-cell hybrid micro-lattice materials, in which the stretching dominated octet cells were adopted as the strengthen phase while the bending dominated body centered cubic (BCC) lattice was chosen as the soft matrix, were proposed to achieve superior mechanical properties and energy absorption performance. Both stochastic and symmetric distribution of octet cells in the BCC lattice were considered. The cell assembly micromechanics finite element model (FEM) was built and validated by the experimental results. Accordingly, virtual tests were conducted to reveal the stress–strain relationship and deformation patterns of the hybrid lattice specimens. Meanwhile, the influence of reinforcement volume fraction and strut material on the energy absorption ability of the specimens was analyzed. It was concluded that the reinforced octet cells could be adopted to elevate the elastic modulus and collapse strength of the pure BCC micro-lattice material. The multi-cell design could lead to strain hardening in the plateau stress region which resulted in higher plateau stresses and energy absorption capacities. Besides, the symmetric distribution of reinforcements would cause significant stress fluctuations in the plateau region. The obtained results demonstrated that the multi-cell hybrid lattice architectures could be applied to tailor the mechanical behavior and plastic energy absorption performance of micro-lattice materials.

scholarly journals On the mechanical behaviour of additively manufactured metamaterials under dynamic conditions

2021 ◽  
Vol 250 ◽  
pp. 05006
Author(s):  
R. Sancho ◽  
F. Galvez ◽  
C.L. Garrido ◽  
S. Perosanz-Amarillo ◽  
D. Barba
Keyword(s):  
Energy Absorption ◽  
Computational Models ◽  
Volume Fraction ◽  
Testing Machine ◽  
High Energy ◽  
Lattice Structures ◽  
Static Tests ◽  
Dynamic Conditions ◽  
Lattice Materials ◽  
High Energy Absorption

High-energy absorption and light-weightiness are two critical properties for impact protection in the aerospace sector. In the past, the use of periodic honeycomb structures or random porous metallic foams were the preferred route to obtain a good specific-energy absorption performance. In recent years, the use of additive manufacturing has increased the design freedom creating a new generation of reticulated and porous materials: the metamaterials or lattice materials. The internal geometries of these lattice structures can be tuned for superior optimal properties, e.g., energyabsorption and density. However, the mechanics of these materials under impact need to be understood with the purpose of mechanical optimisation, and the computational models validated. In this work, we present the experimental compressive behaviour, at room temperature, of two Ti6Al4V lattice structures under static and dynamic conditions. The quasi-static tests were performed by using a universal testing machine while the dynamic tests were conducted at 480s-1 with a split-Hopkinson bar. In all cases, the deformation process was filmed to analyse the failure. Finally, finiteelement simulations were done, employing the Johnson-Cook model, to describe the response of the alloy. The simulations were able to reflect the failure characteristics of each metamaterial but were not able to describe the macroscopic response due to the differences between the experimental and computational volume fraction.

Impact Properties of Syntactic Foams and Effect of Microballoon Wall Thickness

2006 ◽  
Author(s):  
Tien-Chih Lin ◽  
Nikhil Gupta
Keyword(s):  
Impact Strength ◽  
Total Energy ◽  
Energy Absorption ◽  
Volume Fraction ◽  
Impact Testing ◽  
Syntactic Foams ◽  
Lower Strength ◽  
Impact Properties ◽  
Different Types ◽  
Pendulum Impact

Hollow particle (microballoon) filled polymeric composites, called syntactic foams, are tested for impact properties in the present work. Izod type pendulum impact testing is carried out on eight types of foams, which are made of four types of microballoons used in volume fractions of 0.5 and 0.6. Variation in the volume fraction of microballoons leads to a difference in the total energy absorbed during fracture of different types of foams. Results show that syntactic foams containing microballoons of lower density show lower impact strength because of the lower strength of these microballoons. An increase in microballoon volume fraction leads to decreased energy absorption and strength.

Multi-objective design optimization of additively manufactured lattice structures for improved energy absorption performance

2021 ◽  
pp. 095440622199554
Author(s):  
Recep M Gorguluarslan
Keyword(s):  
Energy Absorption ◽  
Response Surfaces ◽  
Optimization Process ◽  
Truss Optimization ◽  
Size Optimization ◽  
Lattice Structures ◽  
Multi Objective ◽  
Lattice Design ◽  
Highly Nonlinear ◽  
Absorption Performance

This paper aims to improve the energy absorption performance of stiffness-optimized lattice structures by utilizing a multi-objective surrogate-based size optimization that considers the additive manufacturing (AM) constraints such as the minimum printable size. A truss optimization is first utilized at the unit cell level under static compressive loads for stiffness maximization and two optimized lattice configurations called the Face-Body Centered Cubic (FBCC) lattice and the Octet Cubic (OC) are obtained. A multi-objective size optimization process is then carried out to improve the energy absorption capabilities of those lattice designs using non-linear compression simulations with Nylon12 material to be fabricated by the Multi Jet Fusion (MJF) AM process. Thin plate spline (TPS) interpolation method is found to produce very high accuracy as the surrogate model to predict the highly nonlinear response surfaces of energy absorption objectives in the optimization. Compared to the lattice designs with uniform strut diameters, by using the optimization process, the maximum energy absorption efficiency ( EAEm) and the crush stress efficiency ( CSE) of the OC lattice design are further improved up to 33% and 37%, respectively. The FBCC lattice design is also found to have superior EAEm performance compared to the existing lattice types considered for fabricating by the MJF process in the literature.

Heat Transfer in BCC Lattice Materials: Conduction, Convection, and Radiation

2021 ◽  
pp. 115159
Author(s):  
M. Shahrzadi ◽  
M. Davazdah Emami ◽  
A.H. Akbarzadeh
Keyword(s):  
Heat Transfer ◽  
Bcc Lattice ◽  
Lattice Materials

Bending Behavior of Simply-Supported Sandwich Beams Subjected to Large Deflection

2018 ◽  
Vol 777 ◽  
pp. 569-574
Author(s):  
Zhong You Xie
Keyword(s):  
Energy Absorption ◽  
Large Deflection ◽  
Absorption Efficiency ◽  
Sandwich Beams ◽  
Element Simulation ◽  
Energy Absorption Efficiency ◽  
Load Carrying ◽  
Absorption Performance ◽  
Bending Behavior ◽  
The Moment

Due to thin skins and soft core, it is apt to local indentation inducing the concurrence of geometrical and material nonlinearity in sandwich structures. In the paper, finite element simulation is used to investigate the bending behavior of lightweight sandwich beams under large deflection. A modified formulation for the moment at mid-span section of sandwich beams under large deflection is presented, and energy absorption performance is assessed based on energy absorption efficiency. In addition, it is found that no local indentation arises initially, while later that increases gradually with loading displacement increasing. The height of the mid-span section as well as load-carrying capacity decreases significantly with local indentation depth increasing.

Computational Modeling and Energy Absorption Behavior of Thin-Walled Tubes with the Kresling Origami Pattern

2021 ◽  
Vol 62 (2) ◽  
pp. 71-81
Author(s):  
Jiaqiang Li ◽  
Yao Chen ◽  
Xiaodong Feng ◽  
Jian Feng ◽  
Pooya Sareh
Keyword(s):  
Energy Absorption ◽  
Material Properties ◽  
Rotation Angle ◽  
Programming Model ◽  
Mixed Integer ◽  
Element Analysis ◽  
Cross Sectional ◽  
Thin Walled Tube ◽  
Absorption Performance ◽  
Thin Walled

Origami structures have been widely used in various engineering fields due to their desirable properties such as geometric transformability and high specific energy absorption. Based on the Kresling origami pattern, this study proposes a type of thin-walled origami tube the structural configuration of which is found by a mixed-integer linear programming model. Using finite element analysis, a reasonable configuration of a thin-walled tube with the Kresling pattern is firstly analyzed. Then, the influences of different material properties, the rotation angle of the upper and lower sections of the tube unit, and cross-sectional shapes on the energy absorption behavior of the thin-walled tubes under axial compression are evaluated. The results show that the symmetric thin-walled tube with the Kresling pattern is a reasonable choice for energy absorption purposes. Compared with thin-walled prismatic tubes, the thin-walled tube with the Kresling pattern substantially reduces the initial peak force and the average crushing force, without significantly reducing its energy absorption capacity; moreover, it enters the plastic energy dissipation stage ahead of time, giving it a superior energy absorption performance. Besides, the material properties, rotation angle, and cross-sectional shape have considerable influences on its energy absorption performance. The results provide a basis for the application of the Kresling origami pattern in the design of thin-walled energy-absorbingstructures.

scholarly journals Tensile Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composite with Respect to Fiber Volume Fraction

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3335 ◽  
Author(s):  
Seungwon Kim ◽  
Dong Joo Kim ◽  
Sung-Wook Kim ◽  
Cheolwoo Park
Keyword(s):  
Tensile Strength ◽  
Energy Absorption ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Absorption Capacity ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Energy Absorption Capacity ◽  
Direct Tensile ◽  
Direct Tensile Strength

Concrete has high compressive strength, but low tensile strength, bending strength, toughness, low resistance to cracking, and brittle fracture characteristics. To overcome these problems, fiber-reinforced concrete, in which the strength of concrete is improved by inserting fibers, is being used. Recently, high-performance fiber-reinforced cementitious composites (HPFRCCs) have been extensively researched. The disadvantages of conventional concrete such as low tensile stress, strain capacity, and energy absorption capacity, have been overcome using HPFRCCs, but they have a weakness in that the fiber reinforcement has only 2% fiber volume fraction. In this study, slurry infiltrated fiber reinforced cementitious composites (SIFRCCs), which can maximize the fiber volume fraction (up to 8%), was developed, and an experimental study on the tensile behavior of SIFRCCs with varying fiber volume fractions (4%, 5%, and 6%) was carried out through direct tensile tests. The results showed that the specimen with high fiber volume fraction exhibited high direct tensile strength and improved brittleness. As per the results, the direct tensile strength is approximately 15.5 MPa, and the energy absorption capacity was excellent. Furthermore, the bridging effect of steel fibers induced strain hardening behavior and multiple cracks, which increased the direct tensile strength and energy absorption capacity.

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