scholarly journals Application of composite materials for the protection of sea shores and engineering structures against the impact of waves

2010 ◽  
Author(s):  
E. S. Ashpiz ◽  
A. O. Egorov ◽  
A. E. Ushakov
Keyword(s):  
Composite Materials ◽  
Engineering Structures ◽  
The Impact

scholarly journals The Effect of Superabsorbent Polymers on the Microstructure and Self-Healing Properties of Cementitious-Based Composite Materials

2021 ◽  
Vol 11 (2) ◽  
pp. 700
Author(s):  
Irene A. Kanellopoulou ◽  
Ioannis A. Kartsonakis ◽  
Costas A. Charitidis
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Hybrid Structure ◽  
The Self ◽  
Self Healing ◽  
Cementitious Composite ◽  
Superabsorbent Polymers ◽  
Porosity Reduction ◽  
Environment Control ◽  
The Impact

Cementitious structures have prevailed worldwide and are expected to exhibit further growth in the future. Nevertheless, cement cracking is an issue that needs to be addressed in order to enhance structure durability and sustainability especially when exposed to aggressive environments. The purpose of this work was to examine the impact of the Superabsorbent Polymers (SAPs) incorporation into cementitious composite materials (mortars) with respect to their structure (hybrid structure consisting of organic core—inorganic shell) and evaluate the microstructure and self-healing properties of the obtained mortars. The applied SAPs were tailored to maintain their functionality in the cementitious environment. Control and mortar/SAPs specimens with two different SAPs concentrations (1 and 2% bwoc) were molded and their mechanical properties were determined according to EN 196-1, while their microstructure and self-healing behavior were evaluated via microCT. Compressive strength, a key property for mortars, which often degrades with SAPs incorporation, in this work, practically remained intact for all specimens. This is coherent with the porosity reduction and the narrower range of pore size distribution for the mortar/SAPs specimens as determined via microCT. Moreover, the self-healing behavior of mortar-SAPs specimens was enhanced up to 60% compared to control specimens. Conclusively, the overall SAPs functionality in cementitious-based materials was optimized.

An Introduction to the Impact Behaviour of Polymer Composites Using Simplified Beam Models

1998 ◽  
Vol 26 (2) ◽  
pp. 89-110 ◽  
Author(s):  
R. A. W. Mines
Keyword(s):  
Composite Materials ◽  
Undergraduate Students ◽  
Progressive Collapse ◽  
Structural Response ◽  
Sandwich Beams ◽  
Three Point Bending ◽  
The Past ◽  
Structural Case ◽  
The University ◽  
The Impact

The paper describes a final-year undergraduate course that has been taught at the University of Liverpool for the past three years. The main aims of the course are to introduce the student to the design of structures using multi-component (composite) materials and to the performance of such structures under impact loading. Given the complexity of generalized composite behaviour and of structural crashworthiness, a simple structural case is considered, namely, a beam subject to three-point bending. A feature of the course is that not only is linear structural response considered but also non-linear (progressive) structural collapse is covered. The course is split into four parts, namely: (i) analysis of composite laminae, (ii) analysis of laminated beams, (iii) local and global effects in sandwich beams, and (iv) post-failure and progressive collapse of sandwich beams. Static and impact loadings are considered. Comments are made on how the theories are simplified and communicated to the undergraduate students.

A Review on Non-Asbestos Friction Materials: Material Composition and Manufacturing

2018 ◽  
Vol 1150 ◽  
pp. 22-42
Author(s):  
Dinesh Shinde ◽  
Kishore N. Mistry ◽  
Suyog Jhavar ◽  
Sunil Pathak
Keyword(s):  
Composite Materials ◽  
Material Properties ◽  
Single Phase ◽  
Friction Material ◽  
Material Surface ◽  
Surface Wear ◽  
Friction Modifier ◽  
Friction Materials ◽  
Morphological Studies ◽  
The Impact

The peculiar feature of friction materials to absorb the kinetic energy of rotating wheels of an automobile to control the speed makes them remarkable in automobile field. The regulation of speed cannot be achieved with the use of single phase material as a friction material. Consequently, the friction material should be comprised of composite materials which consist of several ingredients. Incidentally, the friction materials were formulated with friction modifier, binders, fillers and reinforcements. Due to its pleasant physical properties, asbestos was being used as a filler. Past few decades, it is found that asbestos causes dangerous cancer to its inhaler, which provides a scope its replacement. Several attempts have been made to find an alternative to the hazardous asbestos. The efforts made by different researchers for the impact of every composition of composite friction material in the field are reviewed and studied for their effect on the properties of friction material. Surface morphological studies of different friction material are compared to interpret the concept of surface wear and its correlation with material properties.

scholarly journals Eco-friendly technology of manufacturing complex products made of composites

2019 ◽  
Vol 140 ◽  
pp. 02004
Author(s):  
Aleksey Ignatov ◽  
Rustam Subkhankulov
Keyword(s):  
Composite Materials ◽  
Cross Section ◽  
Manufacturing Process ◽  
Volume Fraction ◽  
Turbine Blades ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Technological Parameters ◽  
Technological Support ◽  
The Impact

Numerous studies in application of modern composite materials show that their advantages can be successfully implemented in manufacturing «smart» products. This study proposes an improved technological method of manufacturing multilayer environmentally friendly products with a variable cross section, which allows us to expand the possibilities of using modern polymer composite materials (PCM). The technology allows manufacturing products of the most complex geometric shapes, such as wind turbine blades. The aim of the study is the technological support of engineering production in the manufacture of multilayer products of variable cross section made from PCM. Scientific novelty consists in identifying the patterns of implementation and management of the manufacturing process of multilayer products of variable cross-section, and establishing the influence of structural and technological parameters of the manufacturing process on their operational characteristics. The relationship between the pressure of a hot directed air stream and the volume fraction of pores in the hardened material of a multilayer composite product with a variable cross section during layer-by-layer application is investigated. During the study, fundamental and applied principles of mechanical engineering technology, material resistance, adhesion theory, mathematical statistics tools and software were used to process the results of the experiment. Based on the results of laboratory studies, a methodology has been developed for effective prediction of pore content in the manufacturing of composite products. The introduction of the presented technology and the corresponding original methodology into production will reduce the complexity and energy costs of manufacturing composite products, improve their quality and reduce the impact of toxic components from composite materials on workers.

scholarly journals Numerical modeling of the impact behavior of new particulate-loaded composite materials

2003 ◽  
Vol 61 (1-2) ◽  
pp. 151-159 ◽  
Author(s):  
A. Arias ◽  
R. Zaera ◽  
J. López-Puente ◽  
C. Navarro
Keyword(s):  
Numerical Modeling ◽  
Composite Materials ◽  
Impact Behavior ◽  
The Impact

Investigation of Fracture in Transparent Glass Fiber Reinforced Polymer Composites Using Photoelasticity

2002 ◽  
Author(s):  
Sanjeev K. Khanna ◽  
Marius D. Ellingsen ◽  
Robb M. Winter
Keyword(s):  
Composite Materials ◽  
Fatigue Cracks ◽  
Large Body ◽  
Mechanical Analysis ◽  
Pressure Vessels ◽  
High Ratio ◽  
Material Behavior ◽  
Engineering Structures ◽  
Glass Fiber Reinforced ◽  
Fiber Reinforced Polymer Composites

Composite materials are widely used in mechanical structures where a high ratio of strength or stiffness to weight is desired. Not only are composite materials widely used in building recreational equipment such as skis, snowboards or even sports cars, but also multiple types of military aircraft are built from composite materials. Airplane bodies are in principle cyclically loaded pressure vessels and are susceptible to the formation of fatigue cracks, and it is necessary to possess knowledge of how the material behaves with a crack present. In fact, all engineering structures have to be designed with the presence of crack like defects in mind. For traditional engineering materials such as steel and aluminum there exists a large body of knowledge regarding material behavior in the presence of a crack. Furthermore, their isotropic nature eases the process of mechanical analysis. Photoelasticity, an optical method, has been widely used to study fracture in isotropic transparent materials (Irwin, 1962, 1980; Dally, 1979; Daniel, 1984; Kobayashi, et al, 1973; Chona, 1987).

scholarly journals ANALISIS KEKUATAN TARIK DAN IMPAK MATERIAL KOMPOSIT POLIMER DALAM APLIKASI FIBERBOAT

2021 ◽  
Vol 4 ◽  
pp. 121-126
Author(s):  
Rezza Ruzuqi ◽  
Victor Danny Waas
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Materials ◽  
Impact Strength ◽  
Metal Corrosion ◽  
Phase System ◽  
Low Density ◽  
Weight Percentage ◽  
Multi Phase ◽  
The Impact

Composite material is a material that has a multi-phase system composed of reinforcing materials and matrix materials. Causes the composite materials to have advantages in various ways such as low density, high mechanical properties, performance comparable to metal, corrosion resistance, and easy to fabricate. In the marine and fisheries industry, composite materials made from fiber reinforcement, especially fiberglass, have proven to be very special and popular in boat construction because they have the advantage of being chemically inert (both applied in general and marine environments), light, strong, easy to print, and price competitiveness. Thus in this study, tensile and impact methods were used to determine the mechanical properties of fiberglass polymer composite materials. Each test is carried out on variations in the amount of fiberglass laminate CSM 300, CSM 450 and WR 600 and variations in weight percentage 99.5% -0.5%, 99% -1%, 98.5% -1, 5%, 98% -2% and 97.5%-2.5% have been used. The results showed that the greater the number of laminates, the greater the impact strength, which was 413,712 MPa, and the more the percentage of hardener, the greater the impact strength, which was 416,487 MPa. The results showed that the more laminate the tensile strength increased, which was 87.054 MPa, and the more the percentage of hardener, the lower the tensile strength, which was 73.921 MPa.

scholarly journals Damage detection in laminar thermoplastic composite materials by means of embedded optical fibers

2006 ◽  
Vol 60 (7-8) ◽  
pp. 176-179
Author(s):  
Aleksandar Kojovic ◽  
Irena Zivkovic ◽  
Ljiljana Brajovic ◽  
Dragan Mitrakovic ◽  
Radoslav Aleksic
Keyword(s):  
Composite Materials ◽  
Optical Fiber ◽  
Real Time ◽  
Optical Fibers ◽  
Impact Damage ◽  
Experimental Testing ◽  
Low Energy ◽  
Thermoplastic Composite ◽  
Woven Fabric ◽  
The Impact

This paper investigates the possibility of applying optical fibers as sensors for investigating low energy impact damage in laminar thermoplastic composite materials, in real time. Impact toughness testing by a Charpy impact pendulum with different loads was conducted in order to determine the method for comparative measurement of the resulting damage in the material. For that purpose intensity-based optical fibers were built in to specimens of composite materials with Kevlar 129 (the DuPont registered trade-mark for poly(p-phenylene terephthalamide)) woven fabric as reinforcement and thermoplastic PVB (poly(vinyl butyral)) as the matrix. In some specimens part of the layers of Kevlar was replaced with metal mesh (50% or 33% of the layers). Experimental testing was conducted in order to observe and analyze the response of the material under multiple low-energy impacts. Light from the light-emitting diode (LED) was launched to the embedded optical fiber and was propagated to the phototransistor-based photo detector. During each impact, the signal level, which is proportional to the light intensity in the optical fiber, drops and then slowly recovers. The obtained signals were analyzed to determine the appropriate method for real time damage monitoring. The major part of the damage occurs during impact. The damage reflects as a local, temporary release of strain in the optical fiber and an increase of the signal level. The obtained results show that intensity-based optical fibers could be used for measuring the damage in laminar thermoplastic composite materials. The acquired optical fiber signals depend on the type of material, but the same set of rules (relatively different, depending on the type of material) could be specified. Using real time measurement of the signal during impact and appropriate analysis enables quantitative evaluation of the impact damage in the material. Existing methods in most cases use just the intensity of the signal before and after the impact, as the measure of damage. This method could be used to monitor the damage in real time, giving warnings before fatal damage occurs.

scholarly journals The flexural strength of anisotropic composite plates with free edges

2021 ◽  
Vol 21 (1) ◽  
pp. 26-34
Author(s):  
Ashot G. Akopyan ◽  
Keyword(s):  
Composite Materials ◽  
Stress State ◽  
Classical Theory ◽  
Solid Mechanics ◽  
Composite Plates ◽  
Operating Conditions ◽  
Plate Bending ◽  
Structural Elements ◽  
Engineering Structures ◽  
Anisotropic Composite

Modern technology shows increased demands on the strength properties of machines, their parts, as well as various structures, reducing their weight, volume and size, which leads to the need to use anisotropic composite materials. Finding criteria to determine the ultimate strength characteristics of structural elements, engineering structures is one of the urgent problems of solid mechanics. Strength problems in structures are often reduced to finding out the nature of the local stress state at the vertices of the joints of the constituent parts. The solution of this urgent problem for composite anisotropic plates can be found in this article, where the author continues the research in this area, extending them to the bending of anisotropic composite plates. The aim of the work is to study the limit stress state of anisotropic composite plates in the framework of the classical theory of plate bending. The outer edges of the plate are considered to be free. Using the classical theory of anisotropic plate bending in the space of physical and geometric parameters, the hypersurface equations determining the low-stress zones for the edge of the contact surface of a composite cylindrical orthotropic plate are obtained. Modern technological processes of welding, surfacing, soldering and bonding allow to produce structural elements of monolithic interconnected dissimilar anisotropic materials. The combination of different materials with qualities corresponding to certain operating conditions opens up great opportunities to improve the technical and economic characteristics of machines, equipment and structures. It can contribute to a significant increase in their reliability, durability, reduce the cost of production and operation. On this basis, the solution proposed in this work can be useful to increase the strength of composite materials.

Synthesis of Macromolecular Coupling Agent and its Effects on Polystyrene Composites

2014 ◽  
Vol 1053 ◽  
pp. 268-275
Author(s):  
Hong Wen Zhang ◽  
Shi Long Zhou ◽  
Yang Zhang ◽  
Yan Jiang ◽  
Qiang Yu
Keyword(s):  
Composite Materials ◽  
Gel Permeation Chromatography ◽  
Ultraviolet Spectrum ◽  
Butyl Methacrylate ◽  
Coupling Agents ◽  
Resonance Spectroscopy ◽  
H Nmr ◽  
Comprehensive Performance ◽  
Ft Ir ◽  
The Impact

Different molecular weight of block coupling agents with well-defined structures have been synthesized successfully by atom transfer radical polymerization (ATRP) from styrene (St), butyl methacrylate (BMA) and 3-methoxyacryloyl-propyltrimethoxyl silicon (KH-570) are as monomer. The structures and compositions of macromolecular coupling agents have been characterized by means of infrared spectrum (FT-IR), ultraviolet spectrum (UV), nuclear magnetic resonance spectroscopy (1H-NMR) and gel permeation chromatography (GPC). And their effects on the polystyrene/silica (PS/SiO2) composite materials have been studied. The results show that interface compatibility and mechanical properties of composite materials containing macromolecule coupling agents are improved significantly. The composite materials with block macromolecular coupling agents possess more excellent comprehensive performance. Furthermore, the impact strength increased by 110% when comparing with composite materials which are not modified by the coupling agents.

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