Width deformation of thermoplastic prepreg tapes during in-situ Automated Fiber Placement: An experimental investigation into the width deformation mechanism and influence of processing parameters

Increasing demands for composite structures and sustainability goals have resulted in the growth of thermoplastic polymer matrix composites and automated manufacturing technologies. The in-situ Automated Fiber Placement (AFP) manufacturing of thermoplastic prepreg tapes has the potential to provide a fast and cost-effective manufacturing...

Deconsolidation of thermoplastic prepreg tapes during the heating phase of LAFP: An experimental investigation into the effect of a resin-rich surface and tape pre-tension

Laser-assisted automated fiber placement (LAFP) is a promising additive manufacturing technique for the production of large aerospace components. Thermoplastic prepreg tapes will be placed ply-by-ply on top of a mould and in-situ consolidated. This is beneficial for higher production rates. The mechanical performance of thermoplastic composite...

In Situ Characterization of the Reaction-Diffusion Behavior during the Gradient Interphase Formation of Polyetherimide with a High-Temperature Epoxy System

This study presents two novel methods for in situ characterization of the reaction-diffusion process during the co-curing of a polyetherimide thermoplastic interlayer with an epoxy-amine thermoset. The first method was based on hot stage experiments using a computer vision point tracker algorithm to detect and trace diffusion fronts, and the...

Design of a crash energy absorber for a composite aircraft fuselage using a combined analytical-numerical approach

This thesis aims to provide more insight into the crashworthiness behaviour of a composite aircraft fuselage. This is achieved by studying both analytically and numerically the crushing behaviour of composite energy absorbers. The analytical model, which is based on energy dissipation rates, generalises previously derived analytical models to...

Development of innovative automated solutions for the assembly of multifunctional thermoplastic composite fuselage

In this study, the development of innovative tooling and end-effector systems for the assembly of a multifunctional thermoplastic fuselage is presented. The increasing demand for cleaner and new aircraft requires utilising novel materials and technologies. Advanced thermoplastic composites provide an excellent material option thanks to their...

In-line variable spreading of carbon fibre/thermoplastic pre-preg tapes for application in automatic tape placement

This study investigates a device for in-line continuous spreading of carbon fibre/thermoplastic pre-preg tape for potential application in the Laser-Assisted Automatic Tape Placement (LATP) laminate manufacturing process. The spreading device allows variable tape width to be achieved locally during lay-up. Integration of this device in the...

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

Automated 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...

Development of a multifunctional fuselage demonstrator

This paper discusses the development and underlying requirements of a multifunctional lower fuselage demonstrator for a new single aisle aircraft undertaken as part of the Clean Sky 2, Large Passenger Aircraft – Platform 2. The demonstrator will validate high potential combinations of airframe structures, systems, cargo and cabin technology...

Induction welded unidirectional carbon fiber reinforced thermoplastic L-joints: Joint performance and testing methodology

Induction welding is an effective technique for joining unidirectional carbon fiber reinforced thermoplastic composites and L-joints can be produced through quick and cost-effective processing steps. However, due to high localized stresses in the skin-stiffener interface, these L-joints are often avoided in primary aircraft structures. Also, no...

Thermal deconsolidation of thermoplastic prepreg tapes during Laser-Assisted Fiber Placement

The automation of thermoplastic composite production and the drive towards out-of-autoclave processes, is of great relevance in the aerospace and lightweight composite structures industry. Hence, there is a crucial need for developing the current state of material and process understanding, in order to increase the technology readiness levels of...

Fabrication factors influencing mechanical, moisture- and water-related properties of mycelium-based composites

Mycelium-based composites result from the growth of filamentous fungi on organic materials such as agricultural waste streams. These novel biomaterials represent a promising alternative for product design and manufacturing both in terms of sustainable manufacturing processes and circular lifespan. This study shows that their morphology,...

Properties of a thermoplastic composite skin-stiffener interface in a stiffened structure manufactured by laser-assisted tape placement with in situ consolidation

A critically important consideration of stiffened structural panels is the interfacial properties between skin and stiffener. In the present study a novel implementation of laser-assisted tape placement (LATP) was used to produce a representative skin-stiffener of a wingbox from carbon fibre reinforced PEEK. First, a stiffener is manufactured...

Analysis and testing of a thermoplastic composite stiffened panel under compression

This paper presents the numerical analysis of a thermoplastic composite stiffened panel subjected to compression load. The panel has three stringers with a non-symmetric design, with an artificial crack at the middle stringer interface and is made from a fast crystallizing polyetherketoneketone carbon composite. The finite element model...

Low cost thermoplastic composites: An empirical approach

In this report, the possibility of replacing high performance thermoplastic polymers with alternative low-cost ones is investigated. Since thermoplastics offer fast processing times and the opportunity to use efficient production processes which are not suitable for thermosets, they are an attractive material<br/>system for the aerospace...

Ultrasonic Plastic Welding of Dissimilar Materials: Experimental investigation of metal/carbon fiber reinforced thermoplastic joints

Due to EU regulations on fuel consumption, reducing the weight of vehicles has become one of the most important goals of car manufacturers in Europe. Among them, Toyota Motor Europe is one of the worldwide leaders in the research for a sustainable future. Materials like fiber-reinforced plastics and aluminum play a significant role in the...

Analysis of void formation in thermoplastic composites during resistance welding

The process-induced voids during resistance welding of glass fabric-reinforced polyetherimide was investigated. The mechanisms of void formation in adherends, in particular, the residual volatile-induced voids and the fibre de-compaction-induced voids, were analysed. Due to the non-uniform temperature and stress distributions in the joints...