Interlayer Reinforcement Research Articles

Nanostructure-induced performance degradation of WO3·nH2O for energy conversion and storage devices.

Although 2D layered nanomaterials have been intensively investigated towards their application in energy conversion and storage devices, their disadvantages have rarely been explored so far especially compared to their 3D counterparts. Herein, WO3·nH2O (n = 0, 1, 2), as the most common and important electrochemical and electrochromic active nanomaterial, is synthesized in 3D and 2D structures through a facile hydrothermal method, and the disadvantages of the corresponding 2D structures are examined. The weakness of 2D WO3·nH2O originates from its layered structure. X-ray diffraction and scanning electron microscopy analyses of as-grown WO3·nH2O samples suggest a structural transition from 2D to 3D upon temperature increase. 2D WO3·nH2O easily generates structural instabilities by 2D intercalation, resulting in a faster performance degradation, due to its weak interlayer van der Waals forces, even though it outranks the 3D network structure in terms of improved electronic properties. The structural transformation of 2D layered WO3·nH2O into 3D nanostructures is observed via ex situ Raman measurements under electrochemical cycling experiments. The proposed degradation mechanism is confirmed by the morphology changes. The work provides strong evidence for and in-depth understanding of the weakness of 2D layered nanomaterials and paves the way for further interlayer reinforcement, especially for 2D layered transition metal oxides.

Feather‐inspired carbon fiber reinforced polymers with nanofibrous fractal interlayer

Much work has been performed in improving carbon fiber‐reinforced polymer (CFRP) composites to prevent delamination, which is the major defect in laminated composites. Nevertheless, there is not much focus on improving conventional CFRP systems in terms of weight, especially when these are used in primary structures. This article explores whether lighter and at the same time stronger CFRP composites can be manufactured to replace conventional CFRP systems in major applications. Under this perspective, and having established the fundamentals for creating the next generation of light weight structural composites—the featherweight composites—this work introduces a feather‐inspired case which uses a controlled interlayer reinforcement in a fractal and reproducible manner at the macro‐, micro‐, and nano‐scales. By extensively describing the matrix system and the manufacturing processes and focusing on analytically and thermomechanically testing the CNT (Carbon Nanotubes) reinforced nanofiber interlayer system, it is shown that this feather‐inspired CFRP achieves significantly higher mechanical properties as well as potential weight savings. POLYM. COMPOS., 168–181, 2016. © 2014 Society of Plastics Engineers

A state-of-the-art review on geosynthetics in low-volume asphalt roadway pavements

A majority of the applications to incorporate geosynthetics into pavements exist in low-volume asphalt roadways. This paper presents a state-of-the-art review of geosynthetics in pavements for low-volume asphalt roadways. Within that realm, the use of geosynthetics is grouped into three categories for the purpose of this review. The categories are sub-pavement reinforcement, interlayer reinforcement, and other non-reinforcing applications; each has been found to incorporate geosynthetics into pavements with some degree of success. In this paper, selected case studies and major findings of each case study are summarized in the form of a table for each category. From this review, it is clear that geogrids are especially useful as sub-pavement reinforcement. Field experience suggests that geogrids installed into low-volume pavement sections at one-third depth from the top of an aggregate sub-base course have had very good success. Interlayer reinforcement with geosynthetics has been geared to reduce or retard reflective cracking in pavement overlays. This application has been found to be valuable; however, the benefits realized are circumstantial. Geosynthetics as interlayers should only be incorporated when a pavement’s main failure mode is fatigue or age cracking, and should be carefully prescribed based on economics. Other uses of geosynthetics in roadways have been focused on moisture transportation or mitigation of moisture movement. It was found that most of these geosynthetic applications are well developed and can be employed as needed by design engineers.

Curing Pressure Influence of Out-of-Autoclave Processing on Structural Composites for Commercial Aviation

Autoclaving is a process that ensures the highest quality of carbon fiber reinforced polymer (CFRP) composite structures used in aviation. During the autoclave process, consolidation of prepreg laminas through simultaneous elevated pressure and temperature results in a uniform high-end material system. This work focuses on analyzing in a fundamental way the applications of pressure and temperature separately during prepreg consolidation. A controlled pressure vessel (press-clave) has been designed that applies pressure during the curing process while the temperature is being applied locally by heat blankets. This vessel gives the ability to design manufacturing processes with different pressures while applying temperature at desired regions of the composite. The pressure role on the curing extent and its effect on the interlayer region are also tested in order to evaluate the consolidation of prepregs to a completely uniform material. Such studies may also be used to provide insight into the morphology of interlayer reinforcement concepts, which are widely used in the featherweight composites. Specimens manufactured by press-clave, which separates pressure from heat, are analytically tested and compared to autoclaved specimens in order to demonstrate the suitability of the press-clave to manufacture high-quality composites with excessively reduced cost.

Experimental System for Simulating Crack Propagation in Asphalt Pavements and Effectiveness of Geosynthetics in Crack Retardation

Abstract This paper presents the pneumatic moving wheel experimental system and its usefulness in simulating the role of geosynthetics (geogrids) in limiting crack propagation. The simultaneous development of rutting through the experiment was studied as well. The performance of the developed loading system showed that: (1) the moving wheel loading device provides a compact, convenient, simple, and rational experimental tool for investigating the effect of pneumatic wheel loading on the mechanical dynamic behavior of asphaltic layers; (2) two of the failure modes of asphaltic pavements, fatigue cracking and permanent deformation, could be assessed and measured simultaneously; and (3) the relative effect of geosynthetics reinforcement on the retardation of the development of the above distresses during service life was successfully measured to verify quantitatively the contribution of interlayer reinforcement toward the reduction of permanent deformation (rutting) and the increase of asphaltic surface layer life by retarding crack propagation.

High-field installations at the tsukuba magnet laboratories of NRIM

We are now developing, and putting into place, several high-field installations, i.e., a 21 T superconducting magnet, a 40 T class hybrid magnet, long-pulse magnets, and several kinds of characteristic high-field magnets, in a new building of the Tsukuba Magnet Laboratories, which will be open next year in Tsukuba. In this article, we describe the present status and the future plans of these high-field installations at our laboratories. The 21.16 T superconducting magnet with 50 mm bore has been used for experiments on coils of oxide superconductors. Last December we have successfully energized the superconducting part of the 40 T class hybrid magnet up to 14.01 T without quenching. We have fabricated a small pulsed coil, made of a CuAg alloy wire with interlayer reinforcement of glass fiber, which could generate 73.4 T non-destructively in a 10 mm bore with a pulse duration of 5 ms.

Some physical properties of multilayered films

AbstractSome properties of multilayered films are summarized in relation to the properties of the component materials. Polymers may be selected for co‐extrusion into layered films to obtain various combinations of properties, such as barrier, stiffness, heat sealability, optics, and toughness. Properly chosen combinations of high and low modulus materials exhibit mutual interlayer reinforcement. Permeabilities of multilayer films can be calculated from layer geometry and individual component properties.