Modeling of In Situ Strength Development for the Thermoplastic Composite Tow Placement Process

Abstract

The composite tow placement process is a non-autoclave consolidation method that involves in situ consolidation and bonding of thermoplastic tape on a preconsolidated substrate. It can be used as a method for manufacturing large composite structures with a high degree of process control and dimensional accuracy. The bond strength that develops between layers within the laminate ultimately governs the final strength of the part. In this work, a model is presented for predicting through-thickness heat transfer and bond strength development based on intimate contact and healing at the ply interface. Experiments are carried out to validate these results for a wide variety of process conditions, and they show that model based predictive control can be used as a method for process optimization. The numerical results show that bond strength development is significantly affected by the process set points (e.g., head velocity heat input and roller pressures), and that the resulting strength can vary significantly within the part based on these set points.

Simulation of the Tape‐Laying Process for Thermoplastic Matrix Composites

“…It is the only dependency of the viscosity that is currently considered for the simulation of the tape placement process. [12][13][14]18 Polymeric melts show a non-Newtonian flow behavior, which means that the shear stress is not proportional to the shear rate. In most cases, they show a shear thinning behavior, which means that when the shear rate reaches a certain value the viscosity starts to decrease with increasing of the shear rate.…”

“…Despite the fact that Tierney and Gillespie 18 reported pressures up to 200 MPa, which would result in a quite high impact on the pressure to the viscosity for normal polymer melts, there are doubts whether this influence is really relevant for fiber-reinforced tapes, because the amount of the pressure on the matrix is not clear. The problem for this quantification is, that, as it reported by Schledjewski, 22 the fibers in the tape sometimes lie directly on other fibers and build "fiber bridges."…”

Feasibility Study of Fusion Bonding for Carbon Fabric Reinforced Polyphenylene Sulphide by Hot-Tool Welding

“…The main reason for this is that the combined effects of weld pressure, temperature and time on interdiffusion and optimal crystallisation have not yet been considered. This, however, can have a significant influence on the bond strength, has already been documented in literature, both under isothermal as non-isothermal conditions [32,33,34].…”

Interface Characterization of Thermoplastic Skin-Stiffener Composite Manufactured using Laser-Assisted Tape Placement

“…Many other researchers reported the short beam strength of CF/PEEK composites which are produced from heat press, 9 autoclave 7,10 and autoclave re-consolidation of ATP. 11,12 All these studies investigated the short beam strength of flat composite laminates.…”