Discussion of “Prediction of energy absorption capacity of un-cracked and cracked concrete elements through three-point bending tests”1Appears in the Canadian Journal of Civil Engineering, 39: 163–171 [doi: 10.1139/l11-115]

2012 ◽  
Vol 39 (10) ◽  
pp. 1161-1162
Author(s):  
Huanjun Jiang ◽  
Bo Fu
Keyword(s):  
Energy Absorption ◽  
Canadian Journal ◽  
Civil Engineering ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Bending Tests ◽  
Cracked Concrete ◽  
Three Point Bending ◽  
Concrete Elements

Investigation on the Deformation Pattern and Energy Absorption Capacity of Hot-Stamping Structures with Partial Pressing Hardening

2012 ◽  
Vol 488-489 ◽  
pp. 87-92
Author(s):  
Wei Min Zhuang ◽  
Wan Dong Yu ◽  
Yan Hong Chen
Keyword(s):  
Energy Absorption ◽  
Fe Simulation ◽  
Hot Stamping ◽  
Distribution Patterns ◽  
Absorption Capacity ◽  
Deformation Pattern ◽  
Martensitic Steels ◽  
Energy Absorption Capacity ◽  
Three Point Bending ◽  
Set Up

Compared to traditional hot-stamping process, partial pressing hardening (PPH) can alter mechanical properties of metal components in any desired regions by controlling its bainite and martensite distribution. The mechanical property of the structure that is produced by PPH process is quite different from traditional hot-stamping steels (Martensitic steels) and has never been evaluated. Based on the merit of PPH process, this paper investigated the effect of bainite-martensite distribution on the deformation pattern and energy absorption capacity of PPH structures. The FE material models of martensitic and bainitic steel were set up and verified. After that, the deformation pattern and energy absorption capacity of PPH structures with different distribution patterns was investigated and discussed by three-point bending and tensile bending FE simulation.

Numerical and experimental investigation for enhancing the energy absorption capacity of the novel three-dimensional printed sandwich structures

2021 ◽  
pp. 146442072199749
Author(s):  
H Geramizadeh ◽  
S Dariushi ◽  
S Jedari Salami
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Three Dimensional ◽  
Absorption Capacity ◽  
The Novel ◽  
Energy Absorption Capacity ◽  
Fused Deposition ◽  
Honeycomb Sandwich ◽  
Out Of Plane ◽  
Vertical Walls

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.

scholarly journals Dynamic crushing behavior of closed-cell aluminum foams based on different space-filling unit cells

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
S. Talebi ◽  
R. Hedayati ◽  
M. Sadighi
Keyword(s):  
Surface Area ◽  
Dynamic Behavior ◽  
Energy Absorption ◽  
Peak Stress ◽  
Absorption Capacity ◽  
Unit Cell ◽  
Lattice Structures ◽  
Energy Absorption Capacity ◽  
Closed Cell ◽  
Unit Cells

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.

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.

Mechanical Response of Porous Copper Manufactured by Lost Carbonate Sintering Process

2007 ◽  
Vol 539-543 ◽  
pp. 1863-1867 ◽  
Author(s):  
X.F. Tao ◽  
Li Ping Zhang ◽  
Y.Y. Zhao
Keyword(s):  
Particle Size ◽  
Flexural Strength ◽  
Relative Density ◽  
Mechanical Response ◽  
Compaction Pressure ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Three Point Bending ◽  
Porous Copper ◽  
The Impact

This paper investigated the mechanical response of porous copper manufactured by LCS under three-point bending and Charpy impact conditions. The effects of the compaction pressure and K2CO3 particle size used in producing the porous copper samples and the relative density of the samples were studied. The apparent modulus, flexural strength and energy absorption capacity in three-point bending tests increased exponentially with increasing relative density. The impact strength was not markedly sensitive to relative density and had values within 7 – 9 kJ/m2 for the relative densities in the range 0.17 – 0.31. The amount of energy absorbed by a porous copper sample in the impact test was much higher than that absorbed in the three-point bending test, impling that loading strain rate had a significant effect on the deformation mechanisms. Increasing compaction pressure and increasing K2CO3 particle size resulted in significant increases in the flexural strength and the bending energy absorption capacity, both owing to the reduced sintering defects.

Numerical Investigation of Cross-Section on Aluminum A6063 Thin-Walled Structures under Low-Velocity Impact Loading

2014 ◽  
Vol 1019 ◽  
pp. 96-102
Author(s):  
Ali Taherkhani ◽  
Ali Alavi Nia
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Cross Sections ◽  
Peak Load ◽  
Circular Cross Section ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
Crush Strength

In this study, the energy absorption capacity and crush strength of cylindrical thin-walled structures is investigated using nonlinear Finite Elements code LS-DYNA. For the thin-walled structure, Aluminum A6063 is used and its behaviour is modeled using power-law equation. In order to better investigate the performance of tubes, the simulation was also carried out on structures with other types of cross-sections such as triangle, square, rectangle, and hexagonal, and their results, namely, energy absorption, crush strength, peak load, and the displacement at the end of tubes was compared to each other. It was seen that the circular cross-section has the highest energy absorption capacity and crush strength, while they are the lowest for the triangular cross-section. It was concluded that increasing the number of sides increases the energy absorption capacity and the crush strength. On the other hand, by comparing the results between the square and rectangular cross-sections, it can be found out that eliminating the symmetry of the cross-section decreases the energy absorption capacity and the crush strength. The crush behaviour of the structure was also studied by changing the mass and the velocity of the striker, simultaneously while its total kinetic energy is kept constant. It was seen that the energy absorption of the structure is more sensitive to the striker velocity than its mass.

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