scholarly journals CFRP Reinforced Foam Concrete Subjected to Dynamic Compression at Medium Strain Rate

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 10 ◽  
Author(s):  
Xiaojuan Wang ◽  
Lu Liu ◽  
Wenjing Shen ◽  
Hongyuan Zhou
Keyword(s):  
Strain Rate ◽  
Energy Absorption ◽  
Dynamic Compression ◽  
Absorption Capacity ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Foam Concrete ◽  
Energy Absorption Capacity ◽  
Reinforced Polymer ◽  
Medium Strain Rate

Carbon fiber-reinforced polymer (CFRP)-confined foam concrete can be applied in structure protection, e.g., as an impact barrier of bridge piers, in which it is used as the core of the composite impact barrier. Applying CFRP to the foam concrete exterior enhances both the CFRP and the foam concrete, leading to improved compressive performance due to their interaction. In the present study, the carbon-fiber reinforced polymer (CFRP) confining effect on the response and energy absorption of foam concrete subjected to quasi-static and medium-strain-rate dynamic compression was experimentally investigated. The confinement by CFRP changed the response and failure mode of foam concrete specimens from shear in quasi-static load and splitting in dynamic load to crushing, resulting in a significant increase in the load bearing and energy absorption capacity. The composite consisting of CFRP and foam concrete was sensitive to strain rate. In particular, the CFRP–foam concrete interaction led to the remarkably improved resistance and energy absorption capacity of CFRP-confined specimens, which were significantly higher than the sum of those of standalone CFRP and foam concrete.

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.

scholarly journals Performance of Sprayed Fiber Reinforced Polymer Strengthened Timber Beams

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
S. Talukdar ◽  
N. Banthia
Keyword(s):  
Energy Absorption ◽  
Carrying Capacity ◽  
Absorption Capacity ◽  
Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Bonding Agents ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Timber Beams

A study was carried out to investigate the use of Sprayed Fiber Reinforced Polymer (SFRP) for retrofit of timber beams. A total of 10-full scale specimens were tested. Two different timber preservatives and two different bonding agents were investigated. Strengthening was characterized using load deflection diagrams. Results indicate that it is possible to enhance load-carrying capacity and energy absorption characteristics using the technique of SFRP. Of the two types of preservatives investigated, the technique appears to be more effective for the case of creosote-treated specimens, where up to a 51% improvement in load-carrying capacity and a 460% increase in the energy absorption capacity were noted. Effectiveness of the bonding agent used was dependent on the type of preservative the specimen had been treated with.

Effects of Strain Rate on Energy Absorption of High Strength TRIP Steel

2014 ◽  
Vol 552 ◽  
pp. 308-314
Author(s):  
Fei Xiang Yang ◽  
Chao Qun Zhu ◽  
Jun Jie Zhao ◽  
Yan Lin He ◽  
Lin Li
Keyword(s):  
Strain Rate ◽  
Energy Absorption ◽  
Trip Steel ◽  
Static Condition ◽  
Absorption Capacity ◽  
Gradual Transition ◽  
Absorption Properties ◽  
Energy Absorption Capacity ◽  
Dynamic Tension ◽  
Dp Steel

In this paper, the energy absorption properties of 600 MPa and 800MPa grade TRIP and DP steels under different strain rates were investigated. It was shown that the deformation of dynamic specimens concentrated in parallel section under quasi-static stretching, and the strain rate had nothing to do with the energy absorption of these four steel. In the dynamic tension, the TRIP steel had a better energy absorption capacity than it in the quasi-static condition. However, the energy absorption properties of DP steel were not the case. And with the increasing of the strain rate, the energy absorption of these four steel decreased. It was because that instead of “gradual transition”, the transformation of retained austenite changed to “instantaneous transition” in dynamic tension. It made the energy absorption become smaller than it in static tension. Meanwhile, the ductility and the energy absorption capacity of the DP steel were improved, which effected by the adiabatic temperature rise. Owing to suppression of plastic deformation of these steel in dynamic tension, the energy absorption capacity of these four steel decreased with the increasing of strain rate.

The Energy Absorption of Carbon Fiber Reinforced Polymer under Different Impact Speed

2012 ◽  
Vol 535-537 ◽  
pp. 174-177
Author(s):  
Guo Zheng Quan ◽  
Ying Tong ◽  
Gui Sheng Li
Keyword(s):  
Carbon Fiber ◽  
Energy Absorption ◽  
Impact Velocity ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced ◽  
The Impact

In order to investigate the energy absorption of carbon fiber reinforced polymer (CFRP) under different impact velocity, ABAQUS finite element analysis software was used to simulate the impact experiments under the velocities of 1～100m/s. The kinetic energy reduction of the bullet was analyzed. The results shows that: the energy absorption of the composites panel improves with the initial impact velocity increasing, while as the velocity increasing to a certain value, such energy absorption approaches a constant value. And taking further analysis found that property of impact resistance of CFRP has a speed effect, with the strain rate increasing, the dynamic mechanical properties improve.

scholarly journals Compression behavior and energy absorption capacity of woven flax-epoxy composite under various stain rates

2018 ◽  
Vol 183 ◽  
pp. 02062
Author(s):  
Jianxing Hu ◽  
Sha Yin ◽  
Jun Xu
Keyword(s):  
Strain Rate ◽  
Energy Absorption ◽  
Automotive Industry ◽  
Natural Fiber ◽  
Split Hopkinson Pressure Bar ◽  
Epoxy Composite ◽  
Absorption Capacity ◽  
Test Machine ◽  
Reinforced Composites ◽  
Energy Absorption Capacity

Natural fiber reinforced composites serving as building block for structural parts are highly desired due to weight reduction in automotive industry. In the current study, the compressive behavior and energy absorption capacity of woven flax-epoxy composite were experimentally investigated under various strain rates. These tested cubic specimens were manufactured by the vacuum assisted resin infusion (VARI) process and tailoring operation. Quasi-static and dynamic experiments were conducted in a hydraulic servo test machine and a Split Hopkinson Pressure Bar (SHPB), respectively. Preliminary dynamic experimental results revealed significant strain rate sensitivity of woven flax-epoxy composite. The ultimate stress increased by 61.2% from 185.2 MPa to 298.6 MPa and 25.9% for specific energy absorption when the strain rate increased from 0.003/s to 2800/s. Results may serve as a guidance for the further investigation of flax fibers reinforced composites in automotive industry.

scholarly journals In-plane Dynamic Crushing of a Novel Bio-inspired Re-entrant Honeycomb With Negative Poisson's Ratio 

2021 ◽  
Author(s):  
Yonghui Wang ◽  
Qiang He ◽  
Yu Chen ◽  
Hang Gu ◽  
Honggen Zhou
Keyword(s):  
Energy Absorption ◽  
Impact Velocity ◽  
Poisson’S Ratio ◽  
Dynamic Compression ◽  
Absorption Capacity ◽  
Poisson's Ratio ◽  
Negative Poisson’S Ratio ◽  
Energy Absorption Capacity ◽  
Plateau Stress ◽  
Negative Poisson's Ratio

Abstract In order to seek higher crashworthiness and energy absorption capacity, based on biological inspiration, a novel bio-inspired re-entrant honeycomb (BRH) structure with negative Poisson's ratio is designed by selecting lotus leaf vein as biological prototype. The numerical simulation model is established by the nonlinear dynamics software ABAQUS and further compared with the available reference results to verify the feasibility. The dynamic compression behavior and energy absorption capacity of two types of BRH (BRH-Ⅰ and BRH-Ⅱ) are firstly compared with conventional re-entrant honeycomb (RH). The simulation results show that BRH have better mechanical properties and energy absorption characteristics. Then, the crushing behavior of BRH-Ⅱ under different impact velocities are systematically studied. Three typical deformation modes of BRH-Ⅱ are observed through the analysis of deformation profile. The quasi-static plateau stress is closely related to the cellular structure. Based on one-dimensional shock theory, the empirical equations of dynamic plateau stress for BRH-Ⅱ with different relative densities are given by using least-square fitting. In addition, the effects of impact velocity and relative density on plateau stress and energy absorption behavior are also studied. The results show that the energy absorption capacity of BRH-Ⅱ is increased nearly six times compared with RH at the same impact velocity.

Numerical Study of the Effects of Strain Rate and Cell Geometry on Dynamic Behavior of Axial Crushing Honeycomb

2016 ◽  
Vol 725 ◽  
pp. 156-161
Author(s):  
Tsutomu Umeda ◽  
Kohei Kataoka ◽  
Koji Mimura
Keyword(s):  
Strain Rate ◽  
Energy Absorption ◽  
Numerical Study ◽  
Absorption Capacity ◽  
Metal Foil ◽  
Energy Absorption Capacity ◽  
Axial Crushing ◽  
Geometric Conditions ◽  
Crushing Behavior ◽  
Adhesively Bonded Joint

The axial crushing behavior of commercial metal honeycombs was studied with laying emphasis on the effects of strain rate and geometry on its characteristics as an energy absorber. To investigate the effect of strain rate on the energy absorption capacity, the honeycombs of some metal foil materials were numerically modeled by taking the plastic deformation and failure of adhesively-bonded joint between corrugated sheets and the initial imperfection into consideration. The relationship between the enhancement of mean buckling stress and the strain rate was discussed. Furthermore, A3003 honeycomb model was examined by changing its branch angle from 30° to 180° because the geometrical dispersion will also affect the energy absorption capacity. Typical calculated results under different strain rate and geometric conditions were compared with the corresponding experimental results. It was found that the effect of strain rate on the stress – strain relation of the honeycomb structure is greatly relaxed as compared with that of the material itself. The effects of the boundary condition on the crushing behavior of irregular honeycombs were also discussed.

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