Honeycomb is considered an excellent structural material because of its high strength and shear rigidity, excellent energy absorbing property, high impact strength, lower weight, high crushing ...stress, and almost constant crushing force. Honeycomb being a cellular solid is a well-known core used to build a sandwich structure while making structural composites. Because of this excellent mechanical performance, honeycombs are frequently used in the aircraft industry as a core of sandwich panels and in the automotive industry as efficient impact attenuators. The hollow spaces in the honeycomb structure reduce weight but also ensure required strength, provided they are designed correctly. 3D woven honeycomb composite has a promising future in the lightweight application areas and can be the real substitutes for aluminum and other metal alloys as these structures provide structural integrity. In this review, the basic concept of textile-based 3D woven honeycomb composites, engineering design, manufacturing process, structure-properties relationship, and applications of 3D woven honeycomb fabrics and their composites are discussed in detail. Geometrical modeling of 3D woven honeycomb fabric and theoretical analysis of impact, flexural, and compression behavior of their composites are summarized to appreciate the potential advantages of textile-based honeycomb structural composites.
Environmental stringent norms, weight reduction, and the ever-depleting mode of petroleum resources have stimulated the use of textile-based natural fibres as reinforcement in polymeric composites. ...Natural fibres play a significant role in the sustainability of an environmentally friendly future. Natural fibres-based composites have fulfilled the environmental norms and contribute to developing lightweight materials with improved mechanical properties in the automotive sector. The automotive industry is yielding substantial steps towards a more environmentally friendly product by adopting textile fibres as a reinforcement for making various automotive parts, such as door panels, boot lining, instrument panel support, sun visor, wheel box, interior insulation, trunk panel, roof cover, and bumper. The growth rate of natural fibre production is increasing day by day. Each year, high energy-consuming products and synthetic fibres-based composites are being replaced by natural fibre-reinforced polymeric composites because natural fibre-based composites have excellent mechanical properties, relatively low cost (one-third of the cost of glass fibre), low density, and recyclability. This review analysis contributes an overview of the concept of vehicle weight reduction, properties required for composite materials to be used for automotive, most commercially used natural fibres and their use for automotive applications focusing on the matrices for the natural fibre composites (NFCs), natural fibre properties and potential challenges coupled with the use of natural fibres, surface modification methods of some natural fibres being used in the automotive industry and recent advancements in textile fibre-reinforced composites. Thermal properties and processing techniques of natural fibre-reinforced composites (NFRC) are also studied.
•3D woven composites exhibit superior impact behavior as compared to 2D and UD composites.•3D angle interlock reinforced composite possesses highest stress followed by warp interlock and orthogonal ...composites.•Knife penetration test clearly revealed superior protection performance of 3D woven structures.•Composites with 3D woven fabrics as reinforcement show higher values of storage modulus.•Unlike 3D composites, 2D and UD composites did undergo delamination near the point of loading.
This paper presents a comprehensive experimental study of in-plane tensile, compressive, bending, impact resistance, knife penetration and dynamic mechanical analysis (DMA) of unidirectional (UD), two dimensional (2D), three dimensional (3D) orthogonal, 3D angle-interlock and 3D warp interlock multi-layer E-glass tow based woven constructions reinforced composites. Optimization of resin %, hardener % and curing pressure has been carried out using Box and Behnken design for getting maximum possible impact resistance. The results depict that the 3D woven composites have considerably superior impact resistance, knife penetration resistance and DMA behavior as compared to UD and 2D counterparts.
This study aims to enhance the performance of aircrew helmet liners made of 3D woven honeycomb composites through structural improvements. To achieve this, an optimization of the honeycomb design was ...carried out using a statistical tool by varying its geometrical parameters. A Box Behnken design was employed, using three independent factors: cell height, cell size, and cell wall thickness to assess its impact and their interactions on responses. The performance was evaluated using a multiobjective response to maximize impact energy absorption, achieve the target cushion factor, and balance relative density for lightweight design. Since the liner materials were subjected to flatwise compression and dynamic impact tests to assess the performance. Their behavior. The results revealed that the honeycomb core with a cell height of 15 mm, a cell size of 10 mm, and a cell wall thickness of 0.6 mm exhibited good behavior. The response surface analysis and contour plots were used to analyze the interactions and combined effects of variables on each response. It was observed that lesser cell size shows significant improvement in impact energy with higher wall thickness. However, the cushion factor implies inadequate energy mitigation. The analysis comparing desirability and confirmatory experiments highlighted the potential for the aircrew helmet liner to achieve its maximum performance. This study provides valuable insights into the structural design of 3D woven honeycomb composite liners for aircrew helmets and its findings signify the potential for applications in the aerospace and defense industries.
Graphical Abstract
Cyanines during the 1990s: A Review Mishra, Amaresh; Behera, Rajani K; Behera, Pradipta K ...
Chemical reviews,
2000-Jun-14, Volume:
100, Issue:
6
Journal Article
Peer reviewed
An overview of research on cyanines and merocyanines carried out during the 1990s is presented, focusing on the dyes' self-organization, nonlinear optical properties, photodimerization, ...photoisomerization, solvatochromic behavior, behavior in organized system, and use as fluorescent sensors.
Aerogels are three-dimensional nanostructures of non-fluid colloids connected to porous networks made of loosely packed bonded particles. They are often manufactured utilizing the sol-gel technique ...following a drying procedure like supercritical, freeze, or ambient pressure drying. It is the lightest solid material and has several unique qualities, including excellent insulation. Intrinsic brittleness and porous nature make their processing and handling complex, which restrict applicability in several real-world dynamic situations. An effective strategy to strengthen the silica aerogel structure is manufacturing composites with an incorporated fibrous material, which expands their uses considerably. This study covers the scientific synthesis, characterization, and applications of silica aerogel. It encourages silica aerogel composites/blankets that are strengthened by additives and fibrous material made from a wide variety of fibers and fabrics, as well as their manufacturing processes and properties. The effect of fibrous material (fiber and fabric) embedment on the final properties of composites has been extensively discussed, considering the amount of loading in the matrix and their unique characteristics, such as density, shrinkage, mechanical, thermal, and acoustic properties. Fiber-reinforced silica aerogel composites'/blankets applications are briefly discussed, indicating advancements in aerogel functions such as thermal sensors, acoustic insulators, and technical textiles such as protective clothing, medical textiles, and insulation blankets.
We provide sufficient conditions on the wavelets on a local field
K
for the wavelet system to form an unconditional basis for the Hardy space
H
1
(
K
) and the Lebesgue spaces
L
p
(
K
), 1 <
p
< ∞.
Auxetic materials are the materials that expand in the transverse direction when stretched in the longitudinal direction. Auxetics materials are a boon to the field of biomedical engineering, as most ...of the human tissues have auxeticity. In case of repair or transplant of the damaged tissue or organ, auxetic biomedical structures are of great importance as they conform to the usual human body mechanics. Textile materials and structures have been used in the field of biomedical engineering for decades. Of late, auxetic textile structures have received special attention due to intensive research in the field of technical textiles. This review focuses on the application of auxetic textile materials in the field of biomedical engineering.
In this research work the commercially available powder form of alumina (Al2O3) and colloidal solution of silver (Ag) nanoparticles were mixed with water to prepare the nanofluids (NFs) of different ...concentrations. The prepared NFs have been used under MQL mode during the machining of nickel based alloy. The results obtained with NFs have been compared with biodegradable emulsion and dry machining. The small contact angle, more spreadability and tiny droplets size of alumina NFs provided reduced cutting forces, tool wear and chip curling during machining. The phenomenon of tribo-film formation has also been observed with alumina NFs which protected the rake face. Further, the nano-ball bearing effect of silver NFs resulted in good surface finish and reduced abrasion wear.
•Alumina and silver nanoparticles were mixed with water to prepare the nanofluids.•Nanofluids have been used under MQL mode during the machining of Ni based alloy.•Non-machining experiments have been conducted to study the droplet distribution of the fluids.•Machining with nanofluids provided better results as compared to other conditions.
