The main challenging things in railway vehicles are to reduce the consumption of energy for transportation and to decrease the emission of harmful gasses by limiting the consumption of fuel sources. These drawbacks can be overcome by lightweight structures designed for the vehicle bodies and frameworks. The composite materials with fiber reinforcements are the preferred choice for manufacturing lightweight structures to reduce the overall weight of the rail vehicle. The fiber reinforced polymer (FRP) materials possess light‐weightiness, high strength, high stiffness value and are more durable in nature. The researchers are continuously putting their efforts into new innovations in concern towards the replacement of existing conventional materials by FRP composites in railway applications. This review focuses on the overview of FRP composites, the role of composites in past rail vehicles, the rail vehicle component selection and methodology and FRP composites used for various railway components manufacturing with their challenges. Also, this review included the data of FRP composites used in various countries for different railway components applications. Hence, this review is beneficial for the upcoming researchers as a foundation literature to work on railway vehicle applications using variety of FRP materials. Moreover, the challenges are quoted in this review through the comprehensive analysis of literature and hence it provides the information in the form of research gap, so that it would be helpful for the researchers to overcome all the challenges in their upcoming research works.

In recent years, the revolutionary utilization of plant fibers in polymer laminates significantly influenced environmental effects. Presently, there is progression attention in advancing bio-based materials by acquiring plant fibers from lignocellulosic components for different applications like non-structural, structural laminates, automobile components, ballistics, flooring, household utensils, and aerospace parts. These bio-based, eco-friendly components have been recognized as next-generation contestants for higher-efficacy, sustainable, cheap, environmentally friendly, and lightweight composites. Different kinds of synthetic and natural biopolymers and bio-based nanoparticles have been applied to produce sustainable materials. Bio-based polymer composites manifest unique characteristics of both eco-reinforcement and sustainable resin. This review comprehensively communicates the general characteristics and principles of nanoparticles, polymers, and their respective composites. In addition to the machining characteristics, challenges and future perspectives of the polymer composites have also been reviewed.

No abstract

Abstract. Current construction can not be imagined without the use of high-quality mortars and concretes obtained by using high-tech and workable mixtures with lower water content. Obtaining such mixtures in current conditions is impossible without the use of superplasticizers. The use of superplasticizers in concrete technology requires an answer to the question of the influence of superplasticizers on the deformationstrength properties of cement stone. There is a well-known dependence "composition-technology-structureproperties", from which it follows that the strength and deformation properties of cement stone directly depend on the hydration of cement stone in the early stages and structure formation. The influence of some types of superplasticizers on the hydration and structure of cement stone, namely, total, open and conditionally-closed porosity, total contraction, autogenous shrinkage, contraction porosity and hydration heat is considered in the article.

Abstract. The paper is devoted to solving the problem of determining the shape of the rolls of helical rolling mills, depending on the specified profile of the deformation zone. A universal calculation method has been proposed, thanks to which it is possible to determine the shape of the working surface of a roll for all types of helical rolling mills (with mushroom-shaped, cup-shaped, barrel-shaped and disc rolls), any relative arrangement of the rolling axis and rolls axes, and various locations of the deformation zone on the rolling axis. The proposed method is implemented as a standalone exe-application with a simple intuitive interface. The application allows you to output the calculation results into txt-files, which can then be imported into CAD systems to create 3D roll models.