Consolidation during laser assisted fiber placement: Heating, compaction and cooling phases

Thermoplastic composites (TPCs) are emerging in the aerospace industry owing to their advantages over thermoset counterparts such as infinite shelf life, high fracture toughness, chemical and solvent resistance, and recyclability. Also, they are suitable for fast, automated manufacturing since chemical reactions are not required to obtain the...

Deconsolidation of thermoplastic prepreg tapes during rapid laser heating

In this study, the effect of rapid laser heating, which is typical during laser-assisted fiber placement (LAFP), on the micro- and meso- structure of the thermoplastic tape was investigated. Thermoplastic tapes were heated above the melting temperature with different heated lengths (30 and 80 mm and heating times (0.2 and 0.8 s) in a dedicated...

The effect of Laser-Induced deconsolidation on the compaction behavior of thermoplastic composite tapes

The effects of laser-induced deconsolidation on the compaction process of CF/PEEK tapes were investigated. First, tapes with different degrees of deconsolidation were manufactured using a laser heater. This procedure resulted in samples with different waviness, thickness, void content and surface roughness values. Then, as-received and laser...

The influence of inter-laminar thermal contact resistance on the cooling of material during laser assisted fiber placement

The effect of thermal contact resistance (TCR) correlated to the degree of intimate contact (DIC) between the incoming tape and the substrate on the temperature history during laser-assisted fiber placement (LAFP) was investigated. A novel experimental methodology was designed to understand the effect with a non-contact method which did not...

Intimate contact development during laser assisted fiber placement: Microstructure and effect of process parameters

Intimate contact development under LAFP-specific thermal and mechanical boundary conditions/interactions and the effect of process parameters are investigated. One-layer, unidirectional strips of CF/PEKK material were placed with different process parameters on a flat tool surface to create different intimate contact conditions. The concept...

The influence of thermal contact resistance on the thermal history in laser-assisted fiber placement

The temperature history during the laser assisted fiber placement (LAFP) process is very important since it significantly influences the final quality of the structure. Air pockets between subsequent plies, caused by the lack of intimate contact, act as insulators and reduce the through-thickness heat transfer. This phenomenon is commonly...

Effects of Process Parameters on Intimate Contact Development in Laser Assisted Fiber Placement

Intimate contact development has been considered as one of the principal mechanisms for consolidation during the automated fiber placement process. This work aims to investigate the effect of process parameters of LAFP on intimate contact development. Effects of nip point temperature, tool temperature, compaction pressure and placement speed on...

A 3-D finite element model for thermal analysis of laser assisted fiber placement

Laser assisted automated tape or fiber placement (LATP/LAFP) with in-situ consolidation is a promising technique for manufacturing large structures, eliminating the limitations of autoclave curing. Currently, 2-D models are mostly preferred for the thermal analysis of the process. A 3-D, transient thermal finite element model is developed to...