scholarly journals Static test of a variable stiffness thermoplastic composite wingbox under shear, bending and torsion

2020 ◽  
Vol 124 (1275) ◽  
pp. 635-666
Author(s):  
G. Zucco ◽  
V. Oliveri ◽  
M. Rouhi ◽  
R. Telford ◽  
G. Clancy ◽  
...  
Keyword(s):  
Finite Element ◽  
Composite Structures ◽  
Numerical Study ◽  
Variable Stiffness ◽  
Buckling Load ◽  
Thermoplastic Composite ◽  
High Rate ◽  
Thermoplastic Composites ◽  
Test Rig ◽  
Shear Bending

AbstractAutomated manufacturing of thermoplastic composites has found increased interest in aerospace applications over the past three decades because of its great potential in low-cost, high rate, repeatable production of high performance composite structures. Experimental validation is a key element in the development of structures made using this emerging technology. In this work, a $750\times640\times240$ mm variable-stiffness unitised integrated-stiffener out-of-autoclave thermoplastic composite wingbox is tested for a combined shear-bending-torsion induced buckling load. The wingbox is manufactured by in-situ consolidation using a laser-assisted automated tape placement technique. It is made and tested as a demonstrator section located at 85% of the wing semi-span of a B-737/A320 sized aircraft. A bespoke in-house test rig and two aluminium dummy wingboxes are also designed and manufactured for testing the wingbox assembly which spans more than 3m. Prior to testing, the wingbox assembly and the test rig were analysed using a high fidelity finite element method to minimise the failure risk due to the applied load case. The experimental test results of the wingbox are also compared with the predictions made by a numerical study performed by nonlinear finite element analysis showing less than 5% difference in load-displacement behaviour and buckling load and full agreement in predicting the buckling mode shape.

scholarly journals Process Chain Modelling and Analysis for the High-Volume Production of Thermoplastic Composites with Embedded Piezoceramic Modules

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
W. Hufenbach ◽  
M. Gude ◽  
N. Modler ◽  
Th. Heber ◽  
A. Winkler ◽  
...  
Keyword(s):  
Composite Structures ◽  
Continuous Process ◽  
High Volume ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Process Chain ◽  
Widespread Application ◽  
High Volume Production ◽  
Volume Production ◽  
Functional Components

Active composite structures based on thermoplastic matrix systems are highly suited to applications in lightweight structures ready for series production. The integration of additional functional components such as material-embedded piezoceramic actuators and sensors and an electronic network facilitates the targeted control and manipulation of structural behaviour. The current delay in the widespread application of such adaptive structures is primarily attributable to a lack of appropriate manufacturing technologies. It is against this backdrop that this paper contributes to the development of a novel manufacturing process chain characterized by robustness and efficiency and based on hot-pressing techniques tailored to specific materials and actuators. Special consideration is given to detailed process chain modelling and analysis focusing on interactions between technical and technological aspects. The development of a continuous process chain by means of the analysis of parameter influences is described. In conclusion, the use of parameter manipulation to successfully realize a unique manufacturing line designed for the high-volume production of adaptive thermoplastic composite structures is demonstrated.

scholarly journals Advances in Ultrasonic Welding of Thermoplastic Composites: A Review

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1284 ◽  
Author(s):  
Somen K. Bhudolia ◽  
Goram Gohel ◽  
Kah Fai Leong ◽  
Aminul Islam
Keyword(s):  
Composite Structures ◽  
Dissimilar Materials ◽  
Processing Parameters ◽  
Ultrasonic Welding ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Pressure Amplitude ◽  
Advantages And Disadvantages ◽  
Cost Efficient ◽  
Weld Time

The ultrasonic welding (UW) technique is an ultra-fast joining process, and it is used to join thermoplastic composite structures, and provides an excellent bonding strength. It is more cost-efficient as opposed to the conventional adhesive, mechanical and other joining methods. This review paper presents the detailed progress made by the scientific and research community to date in the direction of the UW of thermoplastic composites. The focus of this paper is to review the recent development of the ultrasonic welding technique for thermoplastic composites to thermoplastic composites, and to dissimilar materials. Different ultrasonic welding modes and their processing parameters, namely, weld time, weld pressure, amplitude, type of energy directors (EDs) affecting the welding quality and the advantages and disadvantages of UW over other bonding techniques, are summarized. The current state of the ultrasonic welding of thermoplastic composites and their future perspectives are also deliberated.

Manufacturing procedure to make flat thermoplastic composite laminates by automated fibre placement and their mechanical properties

2016 ◽  
Vol 30 (12) ◽  
pp. 1693-1712 ◽  
Author(s):  
Suong Van Hoa ◽  
Minh Duc Hoang ◽  
Jeff Simpson
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Composite Structures ◽  
High Speed ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Thermoset Composites ◽  
Material Deposition ◽  
Manufacturing Procedure ◽  
Composites Processing

Automated fibre placement (AFP) is a relatively new process for the manufacturing of composite structures. Among many attractive features, it provides high-speed of material deposition, more repeatability in terms of quality of the part, less labour intensive (as compared with traditional methods of manufacturing such as Hand Lay-Up), less waste and the ability to transition more seamlessly from design to manufacturing. AFP can be used to process both thermoset composites and thermoplastic composites. Thermoplastic composites processing holds many potential benefits. This is because if the process is done right in producing parts with good quality, it is fast since it does not require a second process such as curing in an autoclave or oven. For the purpose of comparison of performance and for design, it is necessary to determine the mechanical properties of laminates made using this process. However, there are challenges in making flat coupons for the purpose of testing for mechanical properties. This article presents these challenges and the procedure developed to make flat laminates using a simple AFP machine. Mechanical properties of these laminates are also determined and compared with those obtained from laminates made using conventional autoclave moulding.

The Effect of Infill Patterns and Annealing on Mechanical Properties of Additively Manufactured Thermoplastic Composites

2017 ◽  
Author(s):  
Sridher Rangisetty ◽  
Larry D. Peel
Keyword(s):  
Best Practices ◽  
Composite Structures ◽  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Short Fiber ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Limited Information ◽  
Fused Deposition ◽  
Reinforced Thermoplastics

Recently, carbon fiber-reinforced thermoplastics (CFRTPs) have become popular choices in desktop-based additive manufacturing, but there is limited information on their effective usage. In Fused Deposition Modeling (FDM), a structure is created by layers of extruded beads. The degree of bonding between beads, bead orientation, degree of interlayer bonding, type of infill and the type of material, determines overall mechanical performance. The presence of chopped fibers in thermoplastics increases melt viscosity, changes coefficients of thermal expansion, may have layer adhesion issues, and causes increased wear on nozzles, which makes FDM fabrication of thermoplastic composites somewhat different from neat thermoplastics. In the current work, best practices and the effect of annealing and infill patterns on the mechanical performance of FDM-fabricated composite parts were investigated. Materials included commercially available PLA, CF-PLA, ABS, CF-ABS, PETG, and CF-PETG. Two sets of ASTM D638 tensile and ASTM D790 flexural test specimens with 3 different infill patterns and each material were fabricated, one set annealed, and all tested. Anisotropic behavior was observed as a function of infill pattern. As expected, strength and stiffness were higher when the beads were oriented in the direction of the load, even for neat resins. All fiber-filled tensile results showed an increase in stiffness, but surprisingly, not in strength (likely due to very short fiber lengths). Tests of annealed specimens resulted in clear improvements in tensile strength, tensile stiffness and flexural strength for PLA, CF-PLA, and PETG, CF-PETG but a reduction in flexural stiffness. Also, annealing resulted in mixed improvements for ABS and CF-ABS and is only useful in certain infill patterns. This work also establishes ‘Best Practices’ of FDM-type fabrication of thermoplastic composite structures and documents the minimum critical fiber lengths and fiber fractions of several CF-filled FDM filaments.

Thermal Modeling for the Consolidation Process of Thermoplastic Composite Filament Winding

2000 ◽  
Author(s):  
Alfred C. Loos ◽  
Xiaolan Song
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Coordinate System ◽  
Filament Winding ◽  
Thermoplastic Composite ◽  
Heat Transfer Analysis ◽  
Thermoplastic Composites ◽  
Polar Coordinate System ◽  
Composite Substrate ◽  
Cartesian Coordinate

Abstract The quality of thermoplastic composites depends on the thermal history during processing. Therefore it is important to determine the temperature distribution in the composite during the fabrication process. The objective of this investigation was to develop a comprehensive thermal model of the thermoplastic filament winding process. The model was developed in two parts to calculate the temperature profiles in the towpreg and the composite substrate. A finite element heat transfer analysis for the composite-mandrel assembly was formulated in the polar coordinate system, which facilitates the description of the geometry and the boundary conditions. A four-node ‘sector element’ is used to describe the domain of interest. Sector elements were selected to give a better representation of the curved boundary shape which should improve accuracy with fewer elements compared to a finite element solution in the Cartesian-coordinate system. The second thermal analysis was a Cartesian coordinate, finite element model of the towpreg as it enters the nippoint. The results show that the calculated temperature distribution in the composite substrate compared well with temperature data measured during winding and consolidation. The analysis also agreed with the experimental observation that the melt region is formed on the surface of the incoming towpreg in the nippoint and not on the substrate.

scholarly journals Development of a multipurpose test rig - TAILTEST

2021 ◽  
Vol 349 ◽  
pp. 04017
Author(s):  
Martin Oberthor ◽  
Václav Horák ◽  
Roman Růžek
Keyword(s):  
Variable Stiffness ◽  
Full Scale ◽  
Load Application ◽  
Numerical Analyses ◽  
Thermoplastic Composites ◽  
Test Rig ◽  
Tail Structure

The paper discusses an innovative multipurpose test rig designed with the aim of full-scale rotorcraft fin verification. The developed test rig includes a load application mechanism able to distribute loads representative for rotorcraft tail structure. Both conventional metallic components and innovative thermoplastic composites are used in the rotorcraft tail structure. The test rig will be designed so that a variable stiffness of the fuselage to the fin joint is achieved. Verification of the new tail structure is supported by additional experiments and numerical analyses.

Design of Variable Stiffness Cylinder with Holes Under Bending for Maximum Buckling Load Using Lamination Parameters

2019 ◽  
Author(s):  
Mazen Albazzan ◽  
Brian Tatting ◽  
Ramy Harik ◽  
Zafer Gürdal ◽  
Adriana Blom-Schieber ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Buckling Load ◽  
Lamination Parameters

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

Behaviour of Axially Loaded Composite Wall Panel by Using Finite Element Analysis

2015 ◽  
Vol 815 ◽  
pp. 49-53
Author(s):  
Nur Fitriah Isa ◽  
Mohd Zulham Affandi Mohd Zahid ◽  
Liyana Ahmad Sofri ◽  
Norrazman Zaiha Zainol ◽  
Muhammad Azizi Azizan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Structures ◽  
Element Analysis ◽  
Steel Sheets ◽  
Linear Behavior ◽  
Non Linear ◽  
Composite Wall ◽  
Experimental Values ◽  
Civil Engineering Infrastructure

In order to promote the efficient use of composite materials in civil engineering infrastructure, effort is being directed at the development of design criteria for composite structures. Insofar as design with regard to behavior is concerned, it is well known that a key step is to investigate the influence of geometric differences on the non-linear behavior of the panels. One possible approach is to use the validated numerical model based on the non-linear finite element analysis (FEA). The validation of the composite panel’s element using Trim-deck and Span-deck steel sheets under axial load shows that the present results have very good agreement with experimental references. The developed finite element (FE) models are found to reasonably simulate load-displacement response, stress condition, giving percentage of differences below than 15% compared to the experimental values. Trim-deck design provides better axial resistance than Span-deck. More concrete in between due to larger area of contact is the factor that contributes to its resistance.

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