scholarly journals A Dynamic Model and Parameter Identification of High Viscosity Magnetorheological Fluid-Based Energy Absorber with Radial Flow Mode

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 7059
Author(s):  
Benyuan Fu ◽  
Xianming Zhang ◽  
Zhuqiang Li ◽  
Ruizhi Shu ◽  
Changrong Liao
Keyword(s):  
Dynamic Model ◽  
Energy Absorption ◽  
Specific Energy ◽  
Radial Flow ◽  
Magnetorheological Fluid ◽  
High Viscosity ◽  
Experimental Results ◽  
Flow Mode ◽  
Model Parameters ◽  
Specific Energy Absorption

The excellent suspension stability of the high-viscosity linear polysiloxane magnetorheological fluid (HVLP MRF) makes it a great controlled medium for magnetorheological energy absorbers (MREAs). In our previous work, the Herschel–Bulkley flow model (HB model) was used to describe the shear-thinning rheological behavior and establish the dynamic model of an HVLP MRF-based MREA with radial flow mode. However, as the established model was implicit, the MREA response time increased and the buffer effect was degraded. To improve the time response characteristics, an explicit dynamic model based on the HB model incorporating minor losses (called the E-HBM model) is proposed in this study. The model parameters were identified based on the HBM model. To verify the E-HBM model, five evaluation parameters for the energy absorption performance of the MREA, that is, peak force, mean force, crush force efficiency, specific energy absorption, and stroke efficiency, were introduced to compare the theoretical results with the experimental results obtained using a high-speed drop tower facility with a mass of 600 kg. Then, the relative error of the crush force efficiency, specific energy absorption, and stroke efficiency was quantitatively and comprehensively analyzed considering the E-HBM model and experimental results. The results indicate that the proposed E-HBM model agrees with the impact behavior of the radial flow mode MREA.

scholarly journals Effective design strategy for a high-viscosity magnetorheological fluid–based energy absorber with multi-stage radial flow mode

2018 ◽  
Vol 30 (1) ◽  
pp. 127-139 ◽  
Author(s):  
Benyuan Fu ◽  
Changrong Liao ◽  
Zhuqiang Li ◽  
Lei Xie ◽  
Xiaochun Jian ◽  
...  
Keyword(s):  
Flow Model ◽  
Radial Flow ◽  
Magnetorheological Fluid ◽  
Design Strategy ◽  
High Viscosity ◽  
Flow Mode ◽  
Geometrical Parameters ◽  
Suspension Stability ◽  
Energy Absorber ◽  
Multi Stage

High-viscosity linear polysiloxane–based magnetorheological fluid features its excellent suspension stability. Few reports could be found for magnetorheological energy absorbers using such highly viscous but highly stable magnetorheological fluids as the controlled medium. This study presents a design strategy for the high-viscosity linear polysiloxane–based magnetorheological fluid–based magnetorheological energy absorber with multi-stage radial flow mode. The design strategy is based on the Herschel–Bulkley flow model incorporating minor losses proposed in our prior work. The optimal geometrical parameters were obtained by gradually reducing the number of unknown variables. By analyzing the effect of thicknesses of baffle and outer cylinder and number of coil turns on magnetic circuit, the distribution of magnetic flux in the effective region of magnetorheological valve was optimized. Furthermore, a magnetorheological energy absorber was fabricated and tested using a high-speed drop tower facility with a 600 kg mass. The maximum nominal impact velocity was 4.2 m/s, and the applied current varied discretely from 0, 1, 2, to 3 A. Comparison of our Herschel–Bulkley flow model with measured data was conducted via analysis of peak force, dynamic range, and maximum displacement that indicate the performance of magnetorheological energy absorber. The results validated the effectiveness of the design strategy for the high-viscosity linear polysiloxane–based magnetorheological fluid–based magnetorheological energy absorber.

Mechanical Properties of High Strength Desert Sand Concrete

2015 ◽  
Vol 1095 ◽  
pp. 263-266
Author(s):  
Hai Feng Liu ◽  
Ju Rong Ma ◽  
Yun Long Chen ◽  
Deng Yang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Energy Absorption ◽  
Specific Energy ◽  
High Strength ◽  
Experimental Results ◽  
Replacement Ratio ◽  
Specific Energy Absorption ◽  
Desert Sand

In order to research on the mechanical properties of high strength desert sand concrete, the compressive experiment of high strength desert sand concrete with different desert sand replacement ratio was carried out. The influence of desert sand replacement ratio on the compressive strength and specific energy absorption of high strength desert sand concrete was analyzed. Experimental results shows that the optimum desert sand replacement ratio is from 0 to 40%, which provides advice and guidance to the utility of high strength desert sand concrete in practice.

Impact behavior of a high viscosity magnetorheological fluid-based energy absorber with a radial flow mode

2017 ◽  
Vol 26 (2) ◽  
pp. 025025 ◽  
Author(s):  
Benyuan Fu ◽  
Changrong Liao ◽  
Zhuqiang Li ◽  
Lei Xie ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Radial Flow ◽  
Magnetorheological Fluid ◽  
High Viscosity ◽  
Impact Behavior ◽  
Flow Mode ◽  
Energy Absorber

Dynamic Axial Compression of Square CFRP/Aluminium Tubes

2019 ◽  
Vol 794 ◽  
pp. 202-207
Author(s):  
Rafea Dakhil Hussein ◽  
Dong Ruan ◽  
Guo Xing Lu ◽  
Jeong Whan Yoon ◽  
Zhan Yuan Gao
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Fibre Composite ◽  
Dynamic Tests ◽  
Carbon Fibre Composite ◽  
Specific Energy Absorption ◽  
Static Tests ◽  
Crushing Force ◽  
Cfrp Tubes ◽  
The Impact

Carbon fibre composite tubes have high strength to weight ratios and outstanding performance under axial crushing. In this paper, square CFRP tubes and aluminium sheet-wrapped CFRP tubes were impacted by a drop mass to investigate the effect of loading velocity on the energy absorption of CFRP/aluminium tubes. A comparison of the quasi-static and dynamic crushing behaviours of tubes was made in terms of deformation mode, peak crushing force, mean crushing force, energy absorption and specific energy absorption. The influence of the number of aluminium layers that wrapped square CFRP tubes on the crushing performance of tubes under axial impact was also examined. Experimental results manifested similar deformation modes of tubes in both quasi-static and dynamic tests. The dynamic peak crushing force was higher than the quasi-static counterpart, while mean crushing force, energy absorption and specific energy absorption were lower in dynamic tests than those in quasi-static tests. The mean crushing force and energy absorption decreased with the crushing velocity and increased with the number of aluminium layers. The impact stroke (when the force starts to drop) decreased with the number of aluminium layers.

Ballistic Performance Evaluation of Kevlar-Glass Fibre Hybrid Composite Laminate against Medium Velocity Impact

2021 ◽  
Vol 1165 ◽  
pp. 47-64
Author(s):  
Saurabh S. Kumar ◽  
Rajesh G. Babu ◽  
U. Magarajan
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Glass Fibre ◽  
Hybrid Composite ◽  
Composite Laminates ◽  
Areal Density ◽  
Ballistic Performance ◽  
Performance Requirement ◽  
Specific Energy Absorption ◽  
Fabric Composite

In this paper, the post ballistic impact behaviour of kevlar-glass fibre hybrid composite laminates was investigated against 9×19 mm projectile. Eight different types of composite laminates with different ratios of kevlar woven fibre to glass fibre were fabricated using hand lay-up with epoxy matrix. Ballistic behaviour like ballistic Limit (V50), energy absorption, specific energy absorption and Back Face Signature (BFS) were studied after bullet impact. The results indicated that as the Percentage of glass fibre is increased there was a linear increment in the ballistic behaviour. Addition of 16% kevlar fabric, composite sample meets the performance requirement of NIJ0101.06 Level III-A. Since the maximum specific energy absorption was observed in Pure Kevlar samples and the adding of glass fibre increases the weight and Areal Density of the sample, further investigations need to be carried out to utilize the potential of glass fibre for ballistic applications.

Enhancement in specific energy absorption of invertubes

2019 ◽  
Vol 159 ◽  
pp. 424-440 ◽  
Author(s):  
T.J. Reddy ◽  
V. Narayanamurthy ◽  
Y.V.D. Rao
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Specific Energy Absorption

Crashworthiness performance of concentric structures with different cross-sectional shapes under multiple loading conditions

2020 ◽  
pp. 095440702096188
Author(s):  
Sadjad Pirmohammad
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Absorption Maximum ◽  
Element Model ◽  
Hexagonal Structure ◽  
Loading Conditions ◽  
Cross Sectional ◽  
Specific Energy Absorption ◽  
Multiple Loading ◽  
Energy Absorbing

This paper evaluates the crashworthiness performance of concentric structures with different numbers of tubes (i.e. one to five) and cross-sectional shapes (i.e. hexagon, octagon, decagon and circle) under the multiple loadings of θ = 0, 10, 20 and 30°. An experimentally validated finite element model generated in LS-DYNA is employed to calculate the crashworthiness parameters including the specific energy absorption, maximum crush force and crush force efficiency. A total of 20 concentric structures are analyzed to explore the effects of number of tubes and cross-sectional shapes on the crushing performance. A multi-criteria decision-making method known as TOPSIS is also used to compare and rank the concentric structures in terms of crushing performance. Based on the results, the hexagonal structure including two tubes and octagonal, decagonal and circular structures including three tubes demonstrate the best results among their corresponding cross-sectional shapes. These structures show 9, 39, 38 and 39% higher specific energy absorption compared to their corresponding single tubal cases, respectively. However, in comparison to single tubal cases, they generate 4, 57, 57 and 58% higher maximum crush force, respectively. As such, the values for the improvement of the crush force efficiency are 3, 26, 25 and 21%, respectively. Furthermore, the decagonal structure including three tubes provides the highest energy absorbing characteristics as compared with all the other structures studied in this research. Meanwhile, taking into account all the multiple loading conditions, this structure shows 50% higher specific energy absorption than the hexagonal structure including single tube (as the weakest structure).

Cushioning energy absorption of composite layered structures including paper corrugation, paper honeycomb and expandable polyethylene

2019 ◽  
Vol 54 (3) ◽  
pp. 176-191 ◽  
Author(s):  
Yanfeng Guo ◽  
Meijuan Ji ◽  
Yungang Fu ◽  
Dan Pan ◽  
Xingning Wang ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Peak Stress ◽  
Layered Structures ◽  
Absorption Efficiency ◽  
Compression Stress ◽  
Static Compression ◽  
Specific Energy Absorption ◽  
Energy Absorption Efficiency ◽  
Paper Honeycomb

The composite layered structures including paper corrugation, paper honeycomb and expandable polyethylene are innovative structures of cushioning energy absorption, and the compression and impact resistances of the expandable polyethylene can be enhanced by laminating the corrugated paperboard or honeycomb paperboard. This article evaluated the compression performance and cushioning energy absorption of the composite layered structures by the static compression and drop impact compression tests. On one hand, the static compression properties showed that the total energy absorption, energy absorption per unit volume and stroke efficiency of the composite layered structures were all higher than those of expandable polyethylene. The specific energy absorption was enhanced with the increase in compression strain but almost not affected by the compression rate. The specific energy absorption of the composite layered structures including the expandable polyethylene and honeycomb paperboard was greater than those of the expandable polyethylene and corrugated paperboard. The energy absorption efficiency of the composite layered structures including the expandable polyethylene and corrugated paperboard was large for the low compression stress level, yet that of the composite layered structures including the expandable polyethylene and honeycomb paperboard was large for the high compression stress level. On the other hand, the dynamic compression characteristics showed that the peak stress, energy absorption per unit area, energy absorption per unit volume and specific energy absorption of the composite layered structures embodying paper sandwich cores and expandable polyethylene had linear increasing trends with the increase of drop shock energy. At the same drop impact condition, the composite layered structures including the honeycomb paperboard and expandable polyethylene had better cushioning energy absorption, the peak stress decreased by 23.6% on average, the energy absorption efficiency raised by 8.85% on average and the specific energy absorption increased by 18.1% on average than those including the corrugated paperboard and expandable polyethylene. Therefore, the corrugated paperboard and honeycomb paperboard can helpfully improve the cushioning energy absorption of the expandable polyethylene, and the composite layered structures embodying the expandable polyethylene, corrugated paperboard and honeycomb paperboard may hold excellent packaging protection.

Effect of the Fine Recycled Aggregates on the Dynamic Compressive Behavior of Recycled Mortar

2020 ◽  
Vol 991 ◽  
pp. 62-69
Author(s):  
Sallehan Ismail ◽  
Mohamad Asri Abd Hamid ◽  
Zaiton Yaacob
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
Energy Absorption ◽  
Specific Energy ◽  
Split Hopkinson Pressure Bar ◽  
Recycled Aggregates ◽  
Fine Aggregate ◽  
Peak Strain ◽  
Specific Energy Absorption ◽  
The Impact

This study aims to investigate the dynamic behavior of recycled mortar under impact loading using a split Hopkinson pressure bar (SHPB). Several mortar mixtures were produced by adding various fine recycled aggregates (FRA) to the mixture in replacement percentages of 0%, 25%, 50%, 75%, and 100% of the natural fine aggregate (NFA). The effects of strain rate on compressive strength and specific energy absorption were obtained. Results show that the dynamic compressive strength and specific energy absorption of recycled mortar are highly strain rate dependent; specifically, they increase nearly linearly with the increase in peak strain rate. However, the compressive strength and specific energy absorption of recycled mortar are generally lower than those of NFA mortar (reference samples) under similar high strain rates. The findings of this research can help researchers and construction practitioners to ascertain the appropriate mix design procedure to optimize the impact strength properties of recycled mortar for protective structural application.

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