Effect of Hot-Wet Storage Aging on Mechanical Response of a Woven Thermoplastic Composite

Aerospace ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 18
Author(s):  
Theofanis S. Plagianakos ◽  
Kirsa Muñoz ◽  
Diego Saenz-Castillo ◽  
Maria Mora Mendias ◽  
Miguel Jiménez ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Batch Mode ◽  
Static Tests ◽  
Test Execution ◽  
Aerospace Applications ◽  
Wet Storage ◽  
Wide Range ◽  
Fracture Tests

The effect of hot-wet storage aging on the mechanical response of a carbon fiber polyether ether ketone (PEEK)-matrix woven composite has been studied. A wide range of static loads and selected cyclic load tests on the interlaminar fatigue strength were performed. Static tests were conducted in batch mode, including on- and off-axis tension, compression, flexure, interlaminar shear strength (ILSS) and fracture tests in Modes I, II and I/II. Respective mechanical properties have been determined, indicating a degrading effect of aging on strength-related properties. The measured response in general, as well as the variance quantified by batch-mode test execution, indicated the appropriateness of the applied standards on the material under consideration, especially in the case of fracture tests. The material properties presented in the current work may provide a useful basis towards preliminary design with PEEK-based woven thermoplastic composites during service in aerospace applications.

scholarly journals Simulation of laser heating distribution for a thermoplastic composite: effects of AFP head parameters

2020 ◽  
Vol 110 (7-8) ◽  
pp. 2105-2117
Author(s):  
Omar Baho ◽  
Gilles Ausias ◽  
Yves Grohens ◽  
Julien Férec
Keyword(s):  
Laser Beam ◽  
Laser Heating ◽  
Thermal Model ◽  
Laser Energy ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Efficient Production ◽  
Fiber Placement ◽  
Aerospace Applications ◽  
Automated Fiber Placement

Abstract Laser-assisted automated fiber placement (AFP) is highly suitable for an efficient production of thermoplastic-matrix composite parts, especially for aeronautic/aerospace applications. Heat input by laser heating provides many advantages such as better temperature controls and uniform heating projections. However, this laser beam distribution can be affected by the AFP head system, mainly at the roller level. In this paper, a new optico-thermal model is established to evaluate the laser energy quantity absorbed by a poly(ether ether ketone) reinforced with carbon fibers (APC-2). During the simulation process, the illuminated radiative material properties are characterized and evaluated in terms of the roller deformation, the tilt of the robot head, and the reflection phenomenon between the substrate and the incoming tape. After computing the radiative source term using a ray-tracing method, these data are used to predict the temperature distribution on both heated surfaces of the composite during the process. The results show that both the roller deformation and the tilt of head make it possible to focus the laser beam on a small area, which considerably affects the quality of the finished part. These findings demonstrate that this optico-thermal model can be used to predict numerically the insufficient heating area and thermoplastic composites heating law.

scholarly journals Energy absorption capability of laminated plates made of fully thermoplastic composite

2018 ◽  
Vol 232 (8) ◽  
pp. 1389-1401 ◽  
Author(s):  
Simonetta Boria ◽  
Alessandro Scattina
Keyword(s):  
Energy Absorption ◽  
Laminated Plates ◽  
Thermoplastic Composite ◽  
Low Velocity Impact ◽  
Thermoplastic Composites ◽  
Fibre Reinforcement ◽  
Low Velocity ◽  
Wide Range ◽  
The Matrix ◽  
The Impact

The behaviour of composites materials, made of synthetic fibres embedded in a thermoplastic resin, subjected to low velocity impacts, was largely studied in the past. However, in the last years, the use of thermoplastic composites has been increased due to the considerable advantages in terms of recyclability of this family of materials. Thermoplastic composites are composed of polymers with different material’s structure if compared to the more traditional thermoset composite. Consequently, the behaviour of these materials can be different in some loading conditions. Moreover, considering the wide range of thermoplastic composites that have been developed in the last years, the study of the behaviour of these materials, in case of impact, has not been yet widely analysed, in particular considering materials where both the matrix and the reinforcement are made of thermoplastic. In this perspective, the goal of this work is to study the behaviour of a new thermoplastic composite (PURE thermoplastic) in conditions of low velocity impact. In this material, the matrix and the fibre reinforcement are made of polypropylene both. The paper presents the results of an experimental investigation. In particular, a series of impact tests with a drop dart equipment have been carried out on laminates made of PURE thermoplastic. Laminates with different thicknesses have been taken into consideration. The influence of the impact conditions on the material’s behaviour has been investigated and the capability of energy absorption has been studied. The PURE thermoplastic showed a different behaviour in terms of energy absorption and damage mechanisms if compared to the composites presented in the literature. The thickness of the laminate has had influence on the deformation and the damage mechanism of the specimens: with low thickness, the perforation of the specimen has been obtained, whereas, with the higher thickness, the specimens have shown a ductile behaviour and extended plasticity without crack tip. The contact force between the dart and the specimen has been influenced by the energy level of the impact, but with an opposite trend if compared to that of the composites studied in the literature.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

scholarly journals RICE STRAW/THERMOPLASTIC COMPOSITE: EFFECT OF FILLER LOADING, POLYMER TYPE AND MOISTURE ABSORPTION ON THE PERFORMANCE

CERNE ◽  
2016 ◽  
Vol 22 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Hossein Mohammadi ◽  
Seyedmohammad Mirmehdi ◽  
Lisiane Nunes Hugen
Keyword(s):  
Tensile Strength ◽  
Rice Straw ◽  
Moisture Absorption ◽  
Water Immersion ◽  
Filler Loading ◽  
Thermoplastic Composite ◽  
Modulus Of Rupture ◽  
Thermoplastic Composites ◽  
Composite Effect ◽  
Wet Condition

ABSTRAT Thermoplastic composites made with 45, 60 and 75% of rice straw as filler and two types of thermoplastics, virgin polyethylene (PE) and polypropylene (PP) were evaluated. The final boards were made with and without maleic anhydride modified polypropylene (MAPP) at 2% of the total weight of each specimen. The flexural and tensile strengths were measured for dry composites and also measured after 24 h of water immersion of the composites (wet condition). By increasing the filler content, the flexural and tensile strengths and also the density of the specimens decreased. The type of matrix (PE or PP) did not affect significantly the flexural strength, but PP led to higher values of tensile strength for low fiber loadings (45% and 60%). Coupling agents increased the flexural and tensile strength. After water immersion, modulus of elasticity and modulus of rupture were decreased, while tensile strength was less influenced.

Metamaterials with enhanced mechanical properties and tuneable Poisson’s ratio

2021 ◽  
Author(s):  
Amer Alomarah ◽  
Syed Masood ◽  
Dong Ruan
Keyword(s):  
Poisson’S Ratio ◽  
Structural Modification ◽  
Mechanical Response ◽  
Good Alternative ◽  
Poisson's Ratio ◽  
Polyamide 12 ◽  
Loading Direction ◽  
Wide Range ◽  
Potential Applications ◽  
Parametric Studies

Abstract This paper reports a structural modification of an auxetic metamaterial with a combination of representative re-entrant and chiral topologies, namely, a re-entrant chiral auxetic (RCA). The main driving force for the structural modification was to overcome the undesirable properties of the RCA metamaterial such as anisotropic mechanical response under uniaxial compression. Additively manufactured polyamide 12 specimens via Multi Jet Fusion (MJF) were quasi-statically compressed along the two in-plane directions. The experimental results confirmed that the modified structure was less sensitive to the loading direction and the deformation was more uniform. Moreover, similar energy absorptions were obtained when the modified metamaterial was crushed along the two in-plane directions. The energy absorptions were improved from 390 to 950 kJ/m³ and from 500 to 1000 kJ/m³ compared with the RCA when they were crushed along the X and Y directions, respectively. The absorbed energy per unit mass (SEA) also improved from 1.4 to 2.9 J/g and from 1.78 to 3.1 J/g compared with that of the RCA under the axial compression along the X and Y directions. Furthermore, parametric studies were performed and the effects of geometric parameters of the modified metamaterial were numerically investigated. Tuneable auxetic feature was obtained. The energy absorption and Poisson’s ratio of the modified metamaterial offer it a good alternative for a wide range of potential applications in the areas such as aerospace, automotive, and human protective equipment.

scholarly journals Mechanical Properties of Compression Moulded Aggregate-Reinforced Thermoplastic Composite Scrap

2021 ◽  
Vol 5 (11) ◽  
pp. 299
Author(s):  
Julien Moothoo ◽  
Mahadev Bar ◽  
Pierre Ouagne
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Test Method ◽  
Thermoplastic Composite ◽  
Recycled Aggregate ◽  
Thermoplastic Composites ◽  
Mechanical Recycling ◽  
Compression Moulding ◽  
Grain Sizes ◽  
Recycled Composites

Recycling of thermoplastic composites has drawn a considerable attention in the recent years. However, the main issue with recycled composites is their inferior mechanical properties compared to the virgin ones. In this present study, an alternative route to the traditional mechanical recycling technique of thermoplastic composites has been investigated with the view to increase mechanical properties of the recycled parts. In this regard, the glass/polypropylene laminate offcuts are cut in different grain sizes and processed in bulk form, using compression moulding. Further, the effect of different grain sizes (i.e., different lengths, widths and thicknesses) and other process-related parameters (such as mould coverage) on the tensile properties of recycled aggregate-reinforced composites have been investigated. The tensile properties of all composite samples are tested according to ISO 527-4 test method and the significance of test results is evaluated according to Student’s t-test and Fisher’s F-test respectively. It is observed that the tensile moduli of the recycled panels are close to the equivalent quasi-isotropic continuous fibre-reinforced reference laminate while there is a noteworthy difference in the strengths of the recycled composites. At this stage, the manufactured recycled composites show potential for stiffness-driven application.

scholarly journals Thermoplastic Composites for Aerospace Applications

2020 ◽  
pp. 87-114 ◽  
Author(s):  
Marco Barile ◽  
Leonardo Lecce ◽  
Michele Iannone ◽  
Silvio Pappadà ◽  
Pierluca Roberti
Keyword(s):  
Thermoplastic Composites ◽  
Aerospace Applications

scholarly journals Structure and mechanics of aegagropilae fiber network

2017 ◽  
Vol 114 (18) ◽  
pp. 4607-4612 ◽  
Author(s):  
Gautier Verhille ◽  
Sébastien Moulinet ◽  
Nicolas Vandenberghe ◽  
Mokhtar Adda-Bedia ◽  
Patrice Le Gal
Keyword(s):  
Mechanical Response ◽  
Posidonia Oceanica ◽  
Biological Tissues ◽  
Individual Response ◽  
Fiber Network ◽  
Friction Forces ◽  
Fiber Clustering ◽  
Wide Range ◽  
Natural Aggregates ◽  
The Individual

Fiber networks encompass a wide range of natural and manmade materials. The threads or filaments from which they are formed span a wide range of length scales: from nanometers, as in biological tissues and bundles of carbon nanotubes, to millimeters, as in paper and insulation materials. The mechanical and thermal behavior of these complex structures depends on both the individual response of the constituent fibers and the density and degree of entanglement of the network. A question of paramount importance is how to control the formation of a given fiber network to optimize a desired function. The study of fiber clustering of natural flocs could be useful for improving fabrication processes, such as in the paper and textile industries. Here, we use the example of aegagropilae that are the remains of a seagrass (Posidonia oceanica) found on Mediterranean beaches. First, we characterize different aspects of their structure and mechanical response, and second, we draw conclusions on their formation process. We show that these natural aggregates are formed in open sea by random aggregation and compaction of fibers held together by friction forces. Although formed in a natural environment, thus under relatively unconstrained conditions, the geometrical and mechanical properties of the resulting fiber aggregates are quite robust. This study opens perspectives for manufacturing complex fiber network materials.

Enhanced Infrared Heating of Thermoplastic Composite Sheets for Thermoforming Processes

2021 ◽  
Vol 36 (1) ◽  
pp. 35-43
Author(s):  
M. Längauer ◽  
G. Zitzenbacher ◽  
C. Burgstaller ◽  
C. Hochenauer
Keyword(s):  
Steady State ◽  
Composite Materials ◽  
Mechanical Performance ◽  
Heating Time ◽  
Thermoplastic Composite ◽  
Infrared Heating ◽  
Thermoplastic Composites ◽  
Steady State Condition ◽  
Reflector System ◽  
Heating Station

Abstract Thermoforming of thermoplastic composites attracts increasing attention in the community due to the mechanical performance of these materials and their recyclability. Yet there are still difficulties concerning the uniformity of the heating and overheating of parts prior to forming. The need for higher energy efficiencies opens new opportunities for research in this field. This is why this study presents a novel experimental method to classify the efficiency of infrared heaters in combination with different thermoplastic composite materials. In order to evaluate this, different organic sheets are heated in a laboratory scale heating station until a steady state condition is reached. This station mimics the heating stage of an industrial composite thermoforming device and allows sheets to slide on top of the pre-heated radiator at a known distance. By applying thermodynamic balances, the efficiency of chosen parameters and setups is tested. The tests show that long heating times are required and the efficiency of the heating is low. Furthermore, the efficiency is strongly dependent on the distance of the heater to the sheet, the heater temperature and also the number of heating elements. Yet, using a full reflector system proves to have a huge effect and the heating time can be decreased by almost 50%.

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