scholarly journals Modeling and Testing of the Sandwich Composite Manhole Cover Designed for Pedestrian Networks

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1114
Author(s):  
Calin Itu ◽  
Camelia Cerbu ◽  
Teofil-Florin Galatanu
Keyword(s):  
Oriented Strand Board ◽  
Glass Fibers ◽  
Flexural Modulus ◽  
Weight Ratio ◽  
Sandwich Composite ◽  
The Finite Element Method ◽  
Bending Tests ◽  
Two Sides ◽  
Pedestrian Networks ◽  
Glass Reinforced Composites

This research concerning the topic, pursues the design, manufacturing, analysis and testing of the manhole cover that may be used in pedestrian networks. Although there are certain commercially available manhole covers made of glass-reinforced composites, there are a few papers published related to the modelling, simulation and mechanical testing of such parts. Herein, the manhole cover is made of the sandwich composite. The novelty of this kind of cover is to use an oriented strand board (OSB) as the core between two sides containing layers, which are reinforced with glass fibers. The OSB core leads to the increase of the stiffness-weight ratio. The paper describes the materials corresponding to the layers of the composite cover, geometry of the cover, technology used to manufacture the bending specimens and cover tested. Specimens made of materials that correspond to each layer of the cover, are tested in bending in order to determine their mechanical properties (flexural strength and flexural modulus). Bending tests and testing of the cover are also described. The composite manhole cover is also analysed by the finite element method to obtain the state of stresses and strains. The strains of the manhole cover are experimentally measured by using the tensometric method. Finally, comparing the strains with the strains experimentally measured validates the numerical simulation model.

Effect of Hydrogen on Mechanical Properties of Pipeline API 5L X70 Steel

2011 ◽  
Vol 146 ◽  
pp. 213-225 ◽  
Author(s):  
T. Bellahcene ◽  
J. Capelle ◽  
Méziane Aberkane ◽  
Z. Azari
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Embrittlement ◽  
Hydrogen Absorption ◽  
Fatigue Tests ◽  
The Finite Element Method ◽  
Effective Distance ◽  
Bending Tests ◽  
Fatigue Initiation ◽  
Api 5L X70 Steel ◽  
Special Soil

The aim of this work is to study the effects of hydrogen absorption on mechanical properties of pipe API 5L X70 steel. This study is conducted in special soil solution NS4 with pH 6.7 It show that the tensile properties like yield stress, ultimate strength and elongation at failure reduced under hydrogen embrittlement. Several fatigue tests (three (03) points bending tests) on roman tile specimens with notch are performed. Fatigue initiation is detected by acoustic emission. A comparison between specimens electrolytically charged with hydrogen and specimens without hydrogen absorption is made and it has been noted that fatigue initiation time is reduced when hydrogen embrittlement occurs. The field of elastoplastic stresses near the notch is computed by the finite-element method with the Abaqus software package. Effective distance and stress are calculated with the volumetric approach and the Notch intensity Factor of the roman tile specimen is determined for each loading value used in our tests.

scholarly journals Effects of Irradiation by UV- Acceleration on Mechanical Properties of Polymer Blends (Polyester: Starch)

2018 ◽  
Vol 21 (1) ◽  
pp. 147 ◽  
Author(s):  
Sihama I. Salih ◽  
Qahtan A. Hamad ◽  
Safaa N. Abdul Jabbar ◽  
Najat H. Sabit
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Polymer Blends ◽  
Modulus Of Elasticity ◽  
Unsaturated Polyester ◽  
Flexural Modulus ◽  
Weight Ratio ◽  
Weight Fraction ◽  
Elongation Percentage

This work covers mixing of unsaturated polyester (un- polyester) with starch powders as polymer blends and study the effects of irradiation by UV-acceleration on mechanical properties of its. The unsaturated polyester was mixing by starch powders at particle size less than (45 µm) at selected weight fraction of (0, 0.5, 1, 1.5, 2, 2.5 and 3%). These properties involve ultimate tensile strength, modulus of elasticity, elongation percentage, flexural modulus, flexural strength, fracture toughness, impact strength and hardness. The results illustrate decrease in the ultimate tensile strength at and elongation percentage, while increasing modulus of elasticity, with increasing the weight ratio of starch powder to 3 % weight fraction, whereas the maximum value of hardness and flexural, impact properties happened at 1 % weight fraction for types of polymer blends.

scholarly journals Composite materials reinforced with ceramic waste and matrix of unsaturated polyester for applications in the automotive industry

DYNA ◽  
2020 ◽  
Vol 87 (212) ◽  
pp. 251-258
Author(s):  
Jorge Antonio Velasco Parra ◽  
Bladimir A. Ramón Valencia ◽  
William Javier Mora Espinosa
Keyword(s):  
Composite Materials ◽  
Automotive Industry ◽  
Ceramic Industry ◽  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Resin Matrix ◽  
The Finite Element Method ◽  
Bending Tests ◽  
Linear Behavior ◽  
Original Part

In the present investigation an alternative of recycling was evaluated for the residues derived from defective pieces of the ceramic industry, harnessing them as reinforcement in composite materials for the manufacture of parts used in the automotive sector. Sintered clay microparticles to 10% p/p were mixed in an unsaturated polyester resin matrix, through the cast molding technique. Bending tests were performed that showed an elastic-linear behavior, typical of a fragile material. The structure was analyzed through scanning electron microscopy, checking the fragile failure mechanism and a good dispersion of the microparticles. A simulation was carried out with the finite element method, for the design of a motorcycle brake lever, with results that demonstrate a better distribution of stresses and reduction in mass with respect to the original part. Finally, a prototype brake lever was manufactured using computationally validated geometry.

scholarly journals Defect Detection in Aerospace Sandwich Composite Panels Using Conductive Thermography and Contact Sensors

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6689
Author(s):  
David I. Gillespie ◽  
Andrew W. Hamilton ◽  
Robert C. Atkinson ◽  
Xavier Bellekens ◽  
Craig Michie ◽  
...  
Keyword(s):  
Impact Damage ◽  
Primary Repair ◽  
Single Point ◽  
Weight Ratio ◽  
Sandwich Composite ◽  
Thermal Stimulus ◽  
Honeycomb Core ◽  
Commercial Aircraft ◽  
Common Structure ◽  
Carbon Fibre Reinforced Polymer

Sandwich panels consisting of two Carbon Fibre Reinforced Polymer (CFRP) outer skins and an aluminium honeycomb core are a common structure of surfaces on commercial aircraft due to the beneficial strength–weight ratio. Mechanical defects such as a crushed honeycomb core, dis-bonds and delaminations in the outer skins and in the core occur routinely under normal use and are repaired during aerospace Maintenance, Repair and Overhaul (MRO) processes. Current practices rely heavily on manual inspection where it is possible minor defects are not identified prior to primary repair and are only addressed after initial repairs intensify the defects due to thermal expansion during high temperature curing. This paper reports on the development and characterisation of a technique based on conductive thermography implemented using an array of single point temperature sensors mounted on one surface of the panel and the concomitant induced thermal profile generated by a thermal stimulus on the opposing surface to identify such defects. Defects are classified by analysing the differential conduction of thermal energy profiles across the surface of the panel. Results indicate that crushed core and impact damage are detectable using a stepped temperature profile of 80 ∘C The method is amenable to integration within the existing drying cycle stage and reduces the costs of executing the overall process in terms of time-to-repair and manual effort.

The crashworthiness performance of integrally woven sandwich composite panels made using natural and glass fibers

2020 ◽  
pp. 002199832096484
Author(s):  
Tohid Dastan ◽  
Aida Safian ◽  
Mohammad Sheikhzadeh
Keyword(s):  
Glass Fibers ◽  
Computational Cost ◽  
Sandwich Composite ◽  
Sandwich Composites ◽  
Green Composites ◽  
Compression Tests ◽  
Compression Load ◽  
Petroleum Resources ◽  
Cost Efficient ◽  
Composite Samples

As a way to save petroleum resources, considerable efforts were made in the last three decades to develop green composites. Green composites are a category of composite materials in which at least one phase (reinforcement or matrix) is made from renewable resources. An attempt was made to present a simple fabrication process to produce hollow integrally woven sandwich composites. In addition, the potential of jute fibers to be utilized as piles in the core of an integrally woven sandwich composite was assessed and compared to the counterparts made using glass fibers. The crashworthiness performances of integrally woven sandwich composite samples considering the effect of relative density, pile material and the presence of polyurethane foam were investigated through performing quasi-static flat-wise compression tests. Based on the findings, the foam-filled integrally woven sandwich composites exhibited stable compression load-displacement response and better energy absorption properties over pure foam, which make them appropriate for automobile interior components. Moreover, a computational cost-efficient finite element modeling was presented and subsequently validated with experimental results.

The Effect of Fiber Position and Polymerization Condition on the Flexural Properties of Fiber-Reinforced Composite

2004 ◽  
Vol 5 (2) ◽  
pp. 14-26 ◽  
Author(s):  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu
Keyword(s):  
Flexural Strength ◽  
Glass Fibers ◽  
Flexural Modulus ◽  
Flexural Properties ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Monomer Content ◽  
Light Curing ◽  
Polymerization Condition

Abstract The aim of this study was to investigate the influence of the position of the fiber rich layer on the flexural properties of fiber-reinforced composite (FRC) construction. In addition, the total residual monomer content of FRC was quantitatively determined to find out the difference of the effectiveness of two types of light-curing units using liquid chromatography (HPLC). Unidirectional continuous E-glass FRC and hybrid particulate filler composite resins were used in the fabrication of test specimens. Four different positions of the FRC layer were used: compression, neutral, tension, and vertical side position. A three-point bending test (ISO 10477) was performed to measure the flexural properties of the specimens. Position of the FRC layer had a significant effect on the flexural strength (p<0.001, ANOVA). Also, the type of light-curing device had an effect on flexural strength (p<0.001). Specimens with FRC positioned on the compression side showed flexural strength of approximately 250 MPa, whereas FRC positioned on the tension side showed strength ranging from 500 to 600 MPa. Mean flexural modulus with FRC placed horizontally ranged between 9-12 GPa; no significant difference was found between these groups. However when fiber reinforcement was positioned vertically, the flexural modulus raised up to 16 GPa. Specimens with 24 vol% glass fibers contained 52% less residual monomer than specimens without glass fibers. The monomer content was lower in specimens polymerized with the curing device with higher polymerization temperature. In order to optimize flexural strength of low fiber volume fraction, the fibers should be placed at the tension side of the specimen. Citation Lassila LVJ, Vallittu PK. The Effect of Fiber Position and Polymerization Condition on the Flexural Properties of Fiber-Reinforced Composite. J Contemp Dent Pract 2004 May;(5)2:014-026.

Effects of Glass and Carbon Fiber on Nylon 6,6 Crystallization

1993 ◽  
Vol 321 ◽  
Author(s):  
Krisda Siangchaew ◽  
Theodore Davidson ◽  
Matthew Libera
Keyword(s):  
Carbon Fiber ◽  
Thermal Processing ◽  
Glass Fibers ◽  
Processing Condition ◽  
Reinforced Composites ◽  
Dsc Measurements ◽  
Nylon 6,6 ◽  
Carbon Fiber Reinforced Composites ◽  
Transcrystalline Layer ◽  
Glass Reinforced Composites

ABSTRACTThe effects of addition of glass fiber and HMS4 carbon fiber on the crystallization of nylon 6,6 has been investigated using DSC and polarized optical Microscopy (POM). DSC observations indicate that HMS4 fiber lowers the supercooling required to initiate crystallization. A transcrystalline layer is also observed in the near-fiber region of carbon fiber-reinforced composites after DSC. The presence of transcrystallinity and the earlier onset of crystallization for this composite are due to heterogeneous nucleation on carbon fiber surfaces. DSC Measurements of nylon 6,6 with glass fibers show supercoolings similar to those of neat nylon 6,6. Transcrystallinity is also absent in the glass-reinforced composites. These glass fibers appear to be weak nucleation catalysts. Different transcrystalline layer thickness is found to be influenced by thermal processing condition. In addition to transcrystallinity, the HMS4 carbon fiber also influences the bulk morphology of the nylon 6,6.

scholarly journals A Review Of Mechanisms And Fracture Mechanics Of Moisture Ingress In Composite Systems

2021 ◽  
Author(s):  
Janani S. Gopu
Keyword(s):  
Fracture Mechanics ◽  
Composite Structures ◽  
Composite System ◽  
Aerospace Industry ◽  
Weight Ratio ◽  
High Strength ◽  
Honeycomb Structure ◽  
Sandwich Composite ◽  
Composite Systems ◽  
Water Accumulation

Composite materials help realize high strength to weight ratio requirements of the Aerospace Industry. Composite structures and sandwich composite structures are susceptible to moisture ingress. Moisture ingress causes degradation of thermo-mechanical properties of the composite panels. Water accumulation in sandwich composite structures causes rapid degradation of face to core bondline, damage of cells frozen water and even blow off skins owing to sudden pressure build up in the cells of the honeycomb structure. Mechanisms of moisture ingress can be broadly classified into direct and indirect mechanisms. Direct ingress occurs through pre-existing pathways formed by defects in the composite system. Indirect mechanisms are diffusion, Capillary actions, Wicking actions, and Osmosis. The first form of damage in FRP materials is microcracking. The rate of microcracking increases with moisture ingress. Microcracking fracture toughness is a material property for the susceptibility of a composite system to the formation of microcracks. This work implores the mechanisms and the fracture mechanics dominating the formation of microcracks.

scholarly journals Assessment of Mechanical Properties of Biocomposite Material by using Sawdust and Rice Husk

2019 ◽  
Vol 11 (3) ◽  
pp. 147-156
Author(s):  
Prabhat SINGH ◽  
Bhagel SINGH
Keyword(s):  
Rice Husk ◽  
Low Cost ◽  
Glass Fibers ◽  
Testing Machine ◽  
Weight Ratio ◽  
High Strength ◽  
Light Weight ◽  
Universal Testing ◽  
Biocomposite Material ◽  
Main Factor

This paper presents an experimental study on the development of biocomposite material by using sawdust (SD) and rice husk (RH). The use of composite in the present production has increased dramatically since the 1970’s. Traditional material like aluminum, steel, iron and copper etc. may be easily replaced by using this classical biocomposites. The tensile test, hardness and tear resistance test were conducted in a Universal testing machine as per ASTM D638, ASTM D2240 and ASTM D1004 standard, respectively. Although commercial industries have increasingly been concerned with the low cost, light weight and eco-friendly material, the biocomposite material has also a great potential for reduced production cost and low maintenance which have proven to be a main factor in a push towards recycled biocomposites. In this paper we have fabricated a biocomposite model from materials like sawdust, rice husk. The main reason to use biocomposites is that they are more economical and have high strength to weight ratio compared to glass fibers. Hence fabricated material can be used for various applications.

scholarly journals Mechanical Behaviour of Palm Fiber (Palmyra Spout) – Basalt Fiber - Hybrid Composites

2019 ◽  
Vol 9 (1) ◽  
pp. 1064-1070
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composite ◽  
Hybrid Composites ◽  
Glass Fibers ◽  
Natural Fibers ◽  
Basalt Fiber ◽  
Weight Ratio ◽  
Test Sample ◽  
Palm Fiber ◽  
Molding Method

: In general the natural fibers are taken out from the sources of animals and plants. In recent days the natural fibers play an important role in engineering applications like automotive, aerospace and marine industries due to abundant availability, less in cost and zero percentage environment harmless in nature. In this paper the investigation of various mechanical properties of hybrid reinforced composite (Palm fiber Basalt S-glass fiber) is been done on the fabricated samples. The different mechanical property includes tensile, hardness and impact tests etc... The fabrication comprises three layers of Palm and Basalt fibers outer laminated by two layers of S-glass fibers using injection molding method. From the various testing and investigation against the test sample it is been concluded that the fibers in the hybrid set took a major role in determining the important mechanical properties. Thus the fibers present in the hybrid composite increases the strength, stiffness and weight ratio of the composite materials. The various forms and structural analysis of the hybrid composite material are processed by using scanning electron microscope for attaining the better results and application basis

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