Process-Induced Stress and Deformation of Variable-Stiffness Composite Cylinders During Curing

Abstract

Predicting and controlling process-induced deformation of composites during cure can play a significant role in ensuring the accuracy of manufacture and assembly of composite structures. In this paper the parametric investigation on the process-induced stress and deformation of variable-stiffness composite cylinders was presented. The Kamal model was used to simulate the cure kinetic for carbon/epoxy prepreg. A cure hardening instantaneously linear elastic (CHILE) constitutive model was adopted to determine the modulus of matrix resin. Self-consistent micro-mechanical models were employed to represent the mechanical properties and behaviors of the lamina. The three-dimensional model of a variable-stiffness composite cylinder was established using a linear fiber angle variation. The influence of the inner radius, the fiber end angle and the thickness on the stress and deformation of the variable-stiffness cylinder was evaluated using ABAQUS. The results show that the maximum stress increases with increases of the inner radius, the fiber end angle and the thickness. The inner radius of the cylinder have little effect on deformation, the deformation increases as the fiber end angle and the thickness increases. The present model and method can provide a useful tool for prediction of variable-stiffness composite cylinders.

Analysis of Composite Structures in Curing Process for Shape Deformations and Shear Stress: Basis for Advanced Optimization

“…Using Hexcel AS4-8552 was beneficial because of its properties like high impact resistance, reasonable translation of fiber properties, and high strength. The mechanical properties of the Hexcel AS4 material provided by the manufacturer are mentioned in Table 1 [15]. The X and Y directions indicate the fiber directions as parallel (0 • ) and transverse (90 • ), respectively, to the matrix.…”

“…It was connected to the structural analysis in this research to study the deformations and shear stresses using the thermal results. ACCS utilizes a fast three-step simulation approach for comparatively thin laminates (<5 mm thick), where an even temperature distribution is assumed [15].…”

“…Mesh convergence in a finite elemental study defines the relationship between the number of elements and the accuracy of results. It is necessary to use a desired mesh that is acceptable to the shape and size of the used elements [15]. In the current work, element size was selected to be 1 mm by considering the simulation time and accuracy of results.…”

“…Mezeix et al [14] presented a method to predict composite flight structures' deformation using ABAQUS softeware Ansys composite cure simulation is a novel method developed using the Ansys tool, which was used as a part of the work presented in this paper. Curing process analysis is the building block for obtaining accurate results for predicting the final shape of a composite part [15]. G. Fernlund [16] explained the significance of the cure cycle in the dimensional fidelity of autoclave-processed composite parts.…”

Process-Induced Distortions Characterization of MBWK Fabric Reinforced Composite Helmet Shell

“…[ 4 , 5 ]. However, the residual stress is an inevitable problem during the manufacturing process of composites, which are caused by the mismatch of the coefficients of thermal expansion (CTE) between reinforced fiber and matrix, the shrinkage in the resin polymerization reaction during the curing process, and fiber reorientation during the 3D shape forming process [ 6 , 7 , 8 , 9 , 10 , 11 ] Additionally, a number of literatures implied that residual stresses may cause composite delamination and matrix fracture, reduce the failure strength, and influence the performance and service life of composite materials. Additionally, the process-induced distortions (PIDs) may affect the structural integrity even lead composites to fail [ 12 , 13 ].…”