Abstract
A stochastic cure simulation approach is developed and implemented to investigate the influence of fibre misalignment on cure. Image analysis is used to characterize fiber misalignment in a carbon non‐crimp fabric. It is found that variability in tow orientation is significant with a standard deviation of 1.2°. The autocorrelation structure is modeled using the Ornstein‐Uhlenbeck sheet and the stochastic problem is addressed by coupling a finite element model of cure with a Monte Carlo scheme. Simulation of the cure of an angle shaped carbon fiber‐epoxy component shows that fiber misalignment can cause considerable variability in the process outcome with a coefficient of variation in maximum residual stress up to approximately 2% (standard deviation of 1 MPa) and qualitative and quantitative variations in final distortion of the cured part with the standard deviation in twist and corner angle reaching values of 0.4° and 0.05° respectively. POLYM. COMPOS., 38:2642–2652, 2017. © 2015 The Authors Polymer Composites published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers
Highlights
Fiber misalignment is one of the main sources of variability in composites manufacturing
The methodologies developed in this work allow the quantification of the influence of variability in fiber orientation on the cure process outcome
The experimental results show that high specification fabrics can involve considerable geometrical variability, which in turn can introduce significant variation to the process outcome
Summary
Fiber misalignment is one of the main sources of variability in composites manufacturing. Variability in as supplied dry fabrics and pre-pregs is mainly associated with in-plane and out-of-plane tow waviness setting the minimum level of uncertainty in all subsequent steps of composite manufacturing [1,2,3] This uncertainty can affect the forming/draping step introducing significant variability in defect formation [3]. VC 2015 The Authors Polymer Composites published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers is subjected to considerable shear deformation, which may intensify existing geometrical heterogeneities. These phenomena can in turn influence the local fiber volume fraction and porosity distribution, introducing significant variability in permeability [1, 2]. This can affect both the dimensional fidelity of parts and the presence of initial defects such as delaminations and matrix cracks governing mechanical performance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
