A three-step finite element model has been implemented to predict the spring-in of L-shaped parts. The material property development during the cure has been modelled as step changes during transitions between viscous, rubbery and glassy states of the resin. The tool-part interaction is modelled as a sliding interface with a constant sliding shear stress. The effect of various material and geometric variables on the deformation of L-Section parts are investigated by a parameter sensitivity analysis. The spring-in predictions obtained by the finite element method are compared to experimental measurements for unidirectional and cross-ply parts of various thicknesses and radii. Results indicate that although a 2D plane strain model can predict the spring-in measured at the symmetry plane fairly well, it is not sufficient to capture the complex deformation patterns observed.
WhiteSRHahnHT. Process modelling of composite materials: residual stress development during cure. Part II. Experimental validation. J Compos Mater1992; 26(16): 2423–2453.
2.
BogettiTAGillespieJW. Process-induced stress and deformation in thick-section thermoset composite laminates. J Compos Mater1992; 26(5): 626–659.
3.
RadfordDWRennickT. Separating sources of manufacturing distortion in laminated composites. J Reinforc Plast Compos2000; 19(8): 621–641.
4.
ZhuQGeubellePHLiM. Dimensional accuracy of thermoset composites: simulation of process-induced residual stresses. J Compos Mater2001; 35(24): 2171–2205.
5.
JohnstonAVaziriRPoursartipA. A plane strain model for process induced deformation of laminated composite structures. J Compos Mater2000; 35(16): 1435–1469.
6.
FernlundGRahmanNCourdjiR. Experimental and numerical study of the effect of cure cycle, tool surface, aspect ratio, and the lay-up on the dimensional stability of autoclave-processed composite parts. Compos Pt A2002; 33: 341–351.
7.
Darrow DA and Smith LV Jr. Isolating components of processing induced warpage in laminated composites. J Compos Mater 2002; 36(21): 2407–2419.
8.
AlbertCFernlundG. Spring-in and warpage of angled composite laminates. Compos Sci Technol2002; 62: 1895–1912.
9.
WisnomMRGigliottiMErsoyN. Mechanisms generating residual stresses and distortion during manufacture of polymer–matrix composite structures. Compos Pt A2006; 37: 522–529.
10.
TwiggGPoursartipAFernlundG. An experimental method for quantifying tool-part shear interaction during composites processing. Compos Sci Technol2003; 63: 1985–2002.
11.
TwiggGPoursartipAFernlundG. Tool-part interaction in composites processing. Part I: experimental investigation and analytical model. Compos Pt A2004; 35: 121–133.
12.
TwiggGPoursartipAFernlundG. Tool-part interaction in composites processing. Part II: numerical modelling. Compos Pt A2004; 35: 135–141.
13.
ErsoyNPotterKWisnomMR. An experimental method to study the frictional processes during composites manufacturing. Compos Pt A2005; 36: 1536–1544.
14.
PotterKDCampbellMLangerC. The generation of geometrical deformations due to tool/part interaction in the manufacture of composite components. Compos Pt A2005; 36: 301–308.
15.
ArafathARARezaV. Closed-form solution for process-induced stresses and deformation of a composite part cured on a solid tool: part I – flat geometries. Compos Pt A2008; 39: 1106–1117.
16.
ArafathARARezaV. Closed-form solution for process-induced stresses and deformation of a composite part cured on a solid tool: part II – curved geometries. Compos Pt A2009; 40: 1545–1557.
17.
ErsoyNGarstkaTPotterK. Modelling of the spring-in phenomenon in curved parts made of a thermosetting composite. Compos Pt A2013; 41: 410–418.
18.
Garstka T, Ersoy N, Potter K, et al. Observations of tool-part interaction in curved composite laminates. Submitted to J Compos Mater.
