scholarly journals Experimental Determination of the Coefficient of Restitution for Selected Modern Hybrid Composites

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5638
Author(s):  
Witold Wojciech Skórski ◽  
Marcin Obszański ◽  
Maciej Zawisza
Keyword(s):  
Composite Materials ◽  
Hybrid Composites ◽  
Digital Camera ◽  
Coefficient Of Restitution ◽  
Resin Matrix ◽  
Body Parts ◽  
Reinforced Plastics ◽  
First Case ◽  
Materials Used ◽  
Mechanical Devices

Composite materials (fiber reinforced plastics, FRPs) are successfully utilized in the production of various mechanical devices, including land vehicles, marine vessels, and aircrafts. They are primarily used for the production of body parts and hulls. Due to their importance, certain requirements relating to the mechanical properties of the materials used must be met for such applications. One aspect of the passive safety of vehicles is the effects of a possible collision with another object. The behavior of the structure in such a case can be determined based on the coefficient of restitution, which is a measure of energy dissipation after an impact. This paper presents the results of measuring the value of the coefficient of restitution for the selected composite materials, utilizing various reinforcement materials including different types of fibers and wooden veneer. The selected materials included glass, carbon, Kevlar fibers, and veneer from exotic wood in an epoxy resin matrix. The tested samples were made using various methods in order to understand the influence of the technology on the value of the coefficient. The authors determined the coefficient values utilizing two methods based on the measurement of two different physical quantities. In the first case, the height of the rebound of the ram was measured using a fast digital camera; in the second case, the time between successive rebounds of the tool was measured, determined based on the signal from the acceleration sensor. The authors compared the results of the coefficient values obtained using these methods and examined the relationship between the rebound energy and the value of the coefficient of restitution. The results have been discussed, and some conclusions have been made. Among other things, it seems that both methods of measurement are interchangeable with regard to lower impact velocities corresponding to lower heights (up to 300 mm) of the drop of the ram used in the tests.

scholarly journals Research underway in the Minakuchi Lab – new fiber features to control crack propagation in composite materials

Impact ◽  
2020 ◽  
Vol 2020 (4) ◽  
pp. 20-21
Author(s):  
Shu Minakuchi
Keyword(s):  
Composite Materials ◽  
Aerospace Industry ◽  
Reinforced Plastics ◽  
Advanced Composite ◽  
Advanced Composite Materials ◽  
Wide Range ◽  
Technological Developments ◽  
Materials Used ◽  
The University ◽  
Carbon Fibre Reinforced Plastics

Composite materials are materials that are made by combining one or two materials. Composite materials have been used by humans for thousands of years but as technological developments increase, more and more examples of composite materials have been created which has led to a staggering number of innovations in a wide range of different fields. One major example of this is the aerospace industry which relies on materials that are strong but light. It is essential that an aircraft is strong enough to resist the enormous stresses that are placed on it by its mechanisms and the environment in which it operates, but light enough to be propelled thousands of miles into the sky. Some of the most abundant composite materials used in the aerospace industry are carbon fibre reinforced plastics (CFRP) which are the focus of Dr Shu Minakuchi's research team at the Minakuchi Laboratory within the Department of Aeronautics and Astronautics, The University of Tokyo. Minakuchi's team is working on advanced composite materials represented by CFRPs, with a view to overcoming some of the problems associated with cracks from stresses and their propagation.

scholarly journals EFFECT OF POROSITY ON THE MECHANICAL STRENGTH OF COMPOSITE MATERIALS

2013 ◽  
pp. 85-87
Author(s):  
ANJALI ANJALI ◽  
SANJAY CHOUDHRY ◽  
VIJAY KUMAR
Keyword(s):  
Raw Materials ◽  
High Strength ◽  
Resin Matrix ◽  
Marine Structures ◽  
Reinforced Plastics ◽  
Polymer Resin ◽  
Reinforcement Fiber ◽  
Fiber Reinforced Plastics ◽  
Materials Used ◽  
Laminar Shear

Fiber reinforced plastics are the combination of a reinforcement fiber in a thermoset polymer resin matrix, where the reinforcement has an aspect ratio that enables the transfer of loads between fibers, and the fibers are chemically bonded to the resin matrix. FRP are used more and more for primary structures in Commercial ,industrial, aerospace and marine structures Mainly to reduce the weight and increases the strength. The strength of FRP reduce for various reason .among them presence of porosity is one of major factor. This paper describes the work performed by experimentally to analysis the effect of porosity on inter laminar shear strength(ILSS) properties of composite. The raw materials used in this study are epoxy resin with high strength carbon fibre & epoxy with glass fibre in the form of prepreg.

Aging of polymer composite materials under loading. (See Beginning in #10-2020)

2020 ◽  
pp. 2-12
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composite ◽  
Polymer Composite Materials ◽  
Cyclic Loads ◽  
Reinforced Plastics ◽  
Water Exposure ◽  
Laboratory Conditions ◽  
Bending Loads ◽  
Moisture Conditions

A study review of aging polymer composite materials (PCM) under different heat-moisture conditions or water exposure with the sequential or parallel influence of static or cyclic loads in laboratory conditions is presented. The influence of tension and bending loads is compared. Conditions of the different load influence on parameters of carbon-reinforced plastics and glass-reinforced plastics are discussed. Equipment and units for climatic tests of PCM under loading are described. Simulation examples of indices of mechanical properties of PCM under the influence of environment and loads are shown.

Aging of polymer composite materials under loading

2020 ◽  
pp. 7-18
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composite ◽  
Polymer Composite Materials ◽  
Cyclic Loads ◽  
Reinforced Plastics ◽  
Water Exposure ◽  
Laboratory Conditions ◽  
Bending Loads ◽  
Moisture Conditions

A study review of aging polymer composite materials (PCM) under different heat-moisture conditions or water exposure with the sequential or parallel influence of static or cyclic loads in laboratory conditions is presented. The influence of tension and bending loads is compared. Conditions of the different load influence on parameters of carbon-reinforced plastics and glass-reinforced plastics are discussed. Equipment and units for climatic tests of PCM under loading are described. Simulation examples of indices of mechanical properties of PCM under the influence of environment and loads are shown.

Use of composite materials and hybrid composites in wind turbine blades

2021 ◽  
Author(s):  
Sri Sai P. Reddy ◽  
Rohan. Suresh ◽  
Hanamantraygouda. M.B. ◽  
B.P. Shivakumar
Keyword(s):  
Composite Materials ◽  
Wind Turbine ◽  
Hybrid Composites ◽  
Turbine Blades ◽  
Wind Turbine Blades

Surface Charging Considerations for Composite Materials Used in Spacecraft Applications

2015 ◽  
Vol 43 (9) ◽  
pp. 2901-2906
Author(s):  
Justin J. Likar ◽  
Robert E. Lombardi ◽  
Alexander L. Bogorad ◽  
Roman Herschitz
Keyword(s):  
Composite Materials ◽  
Surface Charging ◽  
Materials Used

scholarly journals Morphological characteristic of black-winged myna (acridotheres melanopterus)*

2018 ◽  
Vol 197 ◽  
pp. 06006 ◽  
Author(s):  
Renaldi Ednin Vernia ◽  
Anais Tritto ◽  
Abinawanto Abinawanto ◽  
Nurul Winarni ◽  
Anita mayasari ◽  
...  
Keyword(s):  
Morphological Characteristic ◽  
Sample Selection ◽  
Digital Camera ◽  
Morphological Characteristics ◽  
The Body ◽  
Entire Body ◽  
Body Parts ◽  
Breeding Management ◽  
Black Feather ◽  
Average Body

Black-winged myna (Acridotheres melanopterus) is an endemic bird of Java and Bali, currently critically endangered based on International Union of Conservation for Nature (IUCN) since 2010. The study about black-winged myna morphological characteristic is important because it has two relatives with almost identical features of morphology. The information can be used as a basis in breeding management to avoid hybridization. The study aims to determine the morphological characteristics of black-winged myna. The sample selection was done using purposive sampling method. Data was taken from 36 black-winged mynas with >=2 years old. Data collection was done by measuring and documenting every morphological feature of the observed body parts. Documentation of the wings, back, chest, head and sides of the body are taken from each bird using a digital camera. The results showed that almost the entire body of black-winged myna covered by white feather, black feather only present on the cover of the wings and tail. Black eyes surrounded by yellow skin without feather. The beak is orange with blackish parts around the nostrils. The bird has yellow legs with three fingers at the front and one finger at the back. The average body length of this bird is 22.5 cm, weight 89.02 g, width 5.98 cm, body circumference 14.36 cm and wingspan 38.49 cm.

Assessing of Mechanical Properties of Natural Fiber Reinforced Polymer Matrix Hybrid Composites

2015 ◽  
Vol 766-767 ◽  
pp. 199-204 ◽  
Author(s):  
Kumar Jayachandran Nirmal ◽  
D. Premkumar
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Hybrid Composites ◽  
Natural Fibres ◽  
Fiber Reinforced Polymer ◽  
Resin Matrix ◽  
Reinforced Polymer ◽  
Individual Type

An experimental analysis has been carried out to investigate the mechanical properties of composites reinforced by sisal, coir, and banana fibres into epoxy resin matrix. The natural fibres were extracted by retting and manual processes. The composites fabricated by epoxy resin and reinforcement in the hybrid combination of Sisal-Banana and Sisal-Coir with the volume fraction of fibres varying from 5% to 30%. It has been identified that the mechanical properties increase with the increase of volume fraction of fibres to a certain extent and then decreases. The hybridization of the reinforcement in the composite shows greater mechanical properties when compared to individual type of natural fibres reinforced. For all the composites tested, the tensile strength of the composite increased up to 25% of volume fraction of the fibres and further for the increase in the volume fraction of fibre the mechanical properties were decreased. As same as tensile properties, the flexural and impact strength also increased linearly up to 25% of volume fraction of fibres and further for the increase in the volume fraction of fibre the mechanical properties were slightly decreased. Key Words: Sisal, Banana, Coir, Epoxy, Hybrid composite.

Comparative Studies on the Cutting Performance of CVD Diamond and DLC Coated Inserts in Turning GFRP Composite Materials

2010 ◽  
Vol 431-432 ◽  
pp. 466-469
Author(s):  
Dong Can Zhang ◽  
Bin Shen ◽  
Fang Hong Sun ◽  
Ming Chen ◽  
Zhi Ming Zhang
Keyword(s):  
Composite Materials ◽  
Flank Wear ◽  
Arc Discharge ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Cutting Performance ◽  
Vacuum Arc ◽  
Reinforced Plastics ◽  
Gfrp Composite

The diamond and diamond-like carbon (DLC) films were deposited on the cobalt cemented tungsten carbide (WC-Co) cutting tools respectively adopting the hot filament chemical vapor deposition (HFCVD) technique and the vacuum arc discharge with a graphite cathode. The scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD) and Raman spectroscopy were used to characterize the as-deposited diamond and DLC films. To evaluate their cutting performance, comparative turning tests were conducted using the uncoated WC-Co and as-fabricated CVD diamond and DLC coated inserts, with glass fiber reinforced plastics (GFRP) composite materials as the workpiece. The research results exhibited that diamond and DLC coated inserts had great advantages in cutting tests compared to uncoated insert. The flank wear of the CVD diamond coated insert maintained a very low value about 50μm before the cutting tool failure occurred. For the DLC coated insert, its flank wear always maintained a nearly constant value of 70~200μm during whole 45 minutes turning process. The flank wear of CVD diamond coated insert was lower than that of DLC coated insert before diamond films peeling off.

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