Energy absorption from composite reinforced with high performance auxetic textile structure

2020 ◽  
pp. 002199832096455
Author(s):  
Fernanda Steffens ◽  
Fernando Ribeiro Oliveira ◽  
Raul Fangueiro
Keyword(s):  
Energy Absorption ◽  
High Performance ◽  
Poisson Ratio ◽  
Impact Behavior ◽  
Knitted Fabrics ◽  
Reinforced Composite ◽  
Composite Fabrication ◽  
Impact Experiment ◽  
Key Factor ◽  
The Impact

The objective of this study is to analyze the impact behavior on the basis of energy approach of weft knitted structures, namely a jersey composite and an auxetic composite using high performance yarns. Weft knitted fabrics were produced with the same structural and machine parameters, using 100% para-aramid and hybrid (47% para-aramid and 53% polyamide) structure. Composite fabrication was achieved through hand lay-up using epoxy resin. Negative Poisson ratio of the reinforcing auxetic fabric was transferred from the fabric to the composite developed. Results obtained by drop weight dart impact test show that the impact experiment with different impact loads confirmed the auxetic composites, regardless de material composition, have an increase in the total energy absorption compared to jersey reinforced composite, approximately 2.5 and 4 times more for para-aramid and hybrid composite, respectively. Auxetic composites developed within this work present great potential for applications in different areas, mainly where energy absorption is a key factor to be considered, such as in protection, sports among others.

The Influence of Boundary Condition on the Impact Behavior of High Performance Fabrics

2018 ◽  
Vol 28 ◽  
pp. 47-54 ◽  
Author(s):  
Selim Gürgen
Keyword(s):  
Boundary Condition ◽  
Energy Absorption ◽  
Impact Velocity ◽  
High Performance ◽  
Absorption Capacity ◽  
Impact Behavior ◽  
Finite Element Software ◽  
Fabric Deformation ◽  
Absorption Performance ◽  
The Impact

Boundary condition is an important factor for the impact behavior of fabrics. In the present work, the effect of boundary condition on the impact behavior of fabrics was investigated modeling the impact conditions in a finite element software program. In the numerical simulations, fabric boundary condition and impact velocity were used as variable parameters and their effects were discussed in terms of fabric deformation and energy absorption capacity. Based on the study, the significance of boundary condition gradually diminishes as impact velocity increases. However, at low velocities, fabrics with free edges provide enhanced energy absorption performance in comparison to those with fixed edges. In addition, fabric deformation turns to local scale increasing impact velocity however, at low velocities, deformation is extended over a wider area on the fabrics.

The impact of different proportions of knitting elements on the resistive properties of conductive fabrics

2018 ◽  
Vol 89 (5) ◽  
pp. 881-890 ◽  
Author(s):  
Su Liu ◽  
Yanping Liu ◽  
Li Li
Keyword(s):  
Contact Resistance ◽  
Reference Source ◽  
Wearable Electronics ◽  
Electronic Textiles ◽  
Knitted Fabrics ◽  
Conductive Yarns ◽  
Key Factor ◽  
Resistive Networks ◽  
The Impact ◽  
Resistive Property

Conductive yarn is the key factor in fabricating electronic textiles. Generally, three basic fabric production methods (knit, woven, and non-woven) combined with two finishing processes (embroidery and print) are adopted to embed conductive yarns into fabrics to achieve flexible electronic textiles. Conductive yarns with knit structure are the most flexible and effective form of electronic textiles. Electronic textiles present many advantages over conventional electronics. However, in the process of commercialization of conductive knitted fabrics, it is a great challenge to control the complicated resistive networks in conductive knitted fabrics for the purpose of cost saving and good esthetics. The resistive networks in conductive knitted fabrics contain length-related resistance and contact resistance. The physical forms of conductive yarns in different fabrication structures can be very different and, thus, the contact resistance varies greatly in different fabrics. So far, study of controlling the resistive property of conductive fabrics has not been conducted. Therefore, establishing a systematic method for the industry as a reference source to produce wearable electronics is in great demand. During the industrialization of conductive knitted fabrics, engineers can estimate the resistive property of the fabric in advance, which makes the production process more effective and cost efficient. What is more, the resistive distribution in the same area of knitted fabrics can be fully controlled.

Interplay of fabric structure and shear thickening fluid impregnation in moderating the impact response of high-performance woven fabrics

2020 ◽  
Vol 54 (28) ◽  
pp. 4387-4395
Author(s):  
Sanchi Arora ◽  
Abhijit Majumdar ◽  
Bhupendra Singh Butola
Keyword(s):  
Beneficial Effect ◽  
Energy Absorption ◽  
Impact Energy ◽  
High Performance ◽  
Research Work ◽  
Impact Resistance ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Fabric Structure ◽  
The Impact

The beneficial effect of STF impregnation in enhancing the impact resistance of high-performance fabrics has been extensively reported in the literature. However, this research work reports that fabric structure has a decisive role in moderating the effectiveness of STF impregnation in terms of impact energy absorption. Plain woven fabrics having sett varying from 25 × 25 inch−1 to 55 × 55 inch−1 were impregnated with STF at two different padding pressures to obtain different add-ons. The impact energy absorption by STF impregnated loosely woven fabrics was found to be higher than that of their neat counterparts for both levels of add-on, while opposite trend was observed in case of tightly woven fabrics. Further, comparison of tightly woven plain, 2/2 twill, 3/1 twill and 2 × 2 matt fabrics revealed beneficial effect of STF impregnation, except for the plain woven fabric, establishing that there exists a fabric structure-STF impregnation interplay that tunes the impact resistance of woven fabrics.

Slurry Infiltrated Fibre Concrete with Waste Steel Fibres from Tires - The Behaviour under Static and Dynamic Load

2017 ◽  
Vol 908 ◽  
pp. 76-82 ◽  
Author(s):  
Martina Drdlová ◽  
Oldřich Sviták ◽  
Vladan Prachař
Keyword(s):  
Energy Absorption ◽  
Dynamic Load ◽  
High Performance ◽  
Impact Testing ◽  
Fibre Content ◽  
Homogeneity Test ◽  
Steel Fibres ◽  
Fibre Concrete ◽  
The Impact ◽  
High Performance Fibre

Waste fibres coming from the recycling process of the old tires were incorporated in slurry infiltrated fibre concrete (SIFCON), which is a special type of high performance fibre reinforced concrete with high fibre content. The technological feasibility (i.e. suitability of the waste fibres for SIFCON technology) was assessed using infiltration test and homogeneity test. Test specimens were prepared with three volume fractions (5; 7.5 and 10% by vol.) of waste unclassified fibres. SIFCON with industrial steel fibres (10% by vol.) and high performance fibre concrete with industrial fibres were also cast and tested for comparison purposes. Quasi-static mechanical properties were determined. The impact test was carried out by using an in-house manufactured impact testing machine based on drop test principle. Realized tests confirmed the possibility of using the waste fibres for SIFCON technology. The obtained results indicate, that the usage of waste fibres does not significantly reduce the values of SIFCON flexural and compressive strength at quasi-static load and energy absorption at dynamic load, the values were comparable to the specimens with industrially produced fibres. With increasing fibre content, the mechanical parameters and energy-absorption characteristics at dynamic load are increasing as well.

Preparation of auxetic warp-knitted spacer fabric impregnated with shear thickening fluid for low-velocity impact resistance

2020 ◽  
pp. 152808372092701 ◽  
Author(s):  
Wanli Xu ◽  
Biao Yan ◽  
Dongmei Hu ◽  
Pibo Ma
Keyword(s):  
Shear Rate ◽  
Energy Absorption ◽  
Impact Resistance ◽  
Shear Thickening ◽  
Weight Fraction ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Shear Thickening Fluid ◽  
Spacer Fabric ◽  
The Impact

This paper reports the preparation of auxetic warp-knitted spacer fabric impregnated with shear thickening fluid and studied its impact behavior under low-velocity impact loading. The shear thickening fluids have been prepared by mechanically dispersing 12 nm silica particles with weight fraction of 10, 15, 20, and 25% in various carriers (PEG200, PEG400, and PEG600). Rheological results indicate that shear thickening fluid experiences shear thickening transition at a specific shear rate. The critical shear rate reduces, and initial viscosity and maximum viscosity increase with the increase of silica weight fraction. The higher molecular weight of polyethylene glycols can lead to lower critical shear rate. The impact process of composite under impact loading can be divided into three stages. The warp-knitted spacer fabric with different negative Poisson’s ratio has a significant effect on the impact behavior. The warp-knitted spacer fabric with better auxetic performance endows composite better impact resistance, the specific performance is the deformation depth, and energy absorption and peak load increase with the increase of auxetic effect of fabric. The silica weight fraction of shear thickening fluid can increase the energy absorption of composite due to the shear thickening transition of shear thickening fluid. Shear thickening fluid has a synergistic effect with the auxetic warp-knitted spacer fabric on impact resistance of composite. The various carriers have no obvious influence on the overall energy absorption and impact load of composites.

Impact of mixing and curing temperatures on fresh and hardened states properties of UHPC

2021 ◽  
Author(s):  
Cédric Androuet ◽  
Olivier Deaux ◽  
Jean-Philippe Charron
Keyword(s):  
High Performance ◽  
Poisson Ratio ◽  
Mass Density ◽  
Field Conditions ◽  
Air Content ◽  
High Performance Fiber ◽  
Hardened State ◽  
Normal Strength ◽  
Compressive And Flexural Strengths ◽  
The Impact

New Canadian and American standards for concrete and bridges now provides guidelines for the design, production, curing, material characterization and installation of Ultra-High Performance Fiber Reinforced Concretes (named UHPFRC or UHPC) on structures. However, some technical aspects require more research since fundamental knowledge about UHPC is not as complete as for normal strength concretes (NSC). Among these aspects, knowledge on the properties of UHPC produced under field conditions is scarce. The main goal of the research project was to evaluate the fresh state properties (slump flow, air content, mass density, hydration heat) and hardened state properties (elastic modulus, Poisson ratio, compressive and flexural strengths) of a UHPC subjected to various mixing temperatures (10, 20 and 30°C) and curing temperatures (10, 23 and 35°C) encountered in field conditions. The impact of mixing and curing temperatures on each property is discussed and practical information is provided to help engineers planning the UHPC curing duration and formwork stripping.

scholarly journals Simulation of Low Velocity Impact on Composite Hemispherical Shell

2014 ◽  
Vol 564 ◽  
pp. 406-411
Author(s):  
Parnia Zakikhani ◽  
R. Zahari ◽  
Mohamed Thariq Hameed Sultan
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Experimental Testing ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Element Analysis ◽  
Velocity Impact ◽  
Hemispherical Shell ◽  
The Impact

Impact simulation with finite element analysis is an appropriate manner to reduce the cost and time taken to carry out an experimental testing on a component. In this study, the impact behavior of the composite hemispherical shell induced by low velocity impact is simulated in ABAQUS software with finite element method. To predict the responses of Kevlar fabric/polyester, glass fabric/polyester and carbon fabric/polyester in the form of a hemisphere, once as one layer and then as a three-layered composite under applied force by an anvil. The sequences of layers are changed, to investigate and compare the occurred alternations in the amount of energy absorption, impact force and specific energy absorption (SEA). The comparison of results showed that the highest and the lowest quantity of energy absorption and SEA belong to Carbon/Glass/Kevlar (CGK) and Kevlar/Carbon/Glass (KCG) respectively.

scholarly journals TO DEVELOP AND EVALUATE IMPACT BEHAVIOR OF JUTE FIBRE REINFORCED COMPOSITE

2014 ◽  
pp. 80-83
Author(s):  
A.K. SRIVATAVA ◽  
SANDEEP MISHRA ◽  
ROHIT KANAUJIYA ◽  
RAVI SHUKLA ◽  
TOOFAN SINGH
Keyword(s):  
Water Absorption ◽  
Fibre Composite ◽  
Matrix Material ◽  
Natural Fibre ◽  
Impact Behavior ◽  
Reinforced Composite ◽  
Water Absorption Test ◽  
Izod Impact ◽  
The Impact ◽  
Specific Impact

The objective of this study is to investigate the impact behaviors of composites, metals and water absorption of composite. The Water absorption test is used to determine the amount of water absorbed under specified conditions .These composites (JRFC) are made of natural fibre (Jute) by volume 10% reinforcing in Epoxy (Matrix) Material. The Izod impact conditions have been considered .The result shows the specific impact energy of fibre composite is higher than the other materials.

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