Validation of a Simulation Methodology for Thermoplastic and Thermosetting Composite Materials Considering the Effect of Forming Process on the Structural Performance

This research work investigated the influence of the press molding manufacturing process on the mechanical properties, both for thermoplastic and thermosetting fiber reinforced composite materials. The particular geometry of the case study, called Double Dome, was considered in order to verify the behavior of the Thermoplastic and Thermosetting prepreg in terms of shell thickness variation and fibers shear angle evolution during the thermoforming process. The thermoforming simulation was performed using LS-DYNA® Finite Element Analysis (FEA) code, and the results were transferred by Envyo®, a dedicated mapping tool, into a LS-DYNA® virtual model for the structural simulation. A series of Double Dome specimens was produced with industrial equipment, and a bending experimental test was been carried on. Finally, a numerical-experimental correlation was performed, highlighting a significant forecast of the mechanical properties for the considered component.

Numerical investigation of the effect of thermal gradients on curing performance of autoclaved laminates

Autoclave curing process is one of the most frequently used manufacturing techniques of thermosetting composite materials. An efficient curing process requires good understanding of the thermal behavior of molds and composites during autoclave processing. In this paper, the effect of thermal gradients on curing performance of laminates is investigated through numerical approaches. In the first section, a computational fluid dynamics–finite element method numerical model is established to simulate the temperature field and the process-induced deformation of laminates. Then, a curved composite part with two different structures of mold is introduced to exhibit different temperature and degree of cure gradients during the autoclave process. Furthermore, by analyzing the position errors of measurement points, the deformation of the composite parts in different molds is evaluated. The results suggested that more synchronous curing process and less deformation of the composite part can be achieved by reducing the thermal gradients. In this specific case of a curved part, the range of position errors in X direction (the length direction) is reduced by 86.9% with the redesigned mold.

Numerical Analysis of Curing Residual Stress and Deformation in Thermosetting Composite Laminates with Comparison between Different Constitutive Models

A multi-physics coupling numerical model of the curing process is proposed for the thermosetting resin composites in this paper, and the modified “cure hardening instantaneously linear elastic (CHILE)” model and viscoelastic model are adopted to forecast residual stress and deformation during the curing process. The thermophysical properties of both models are evolved in line with temperature and degree of cure (DOC). Accordingly, the numerical simulation results are improved to be more accurate. Additionally, the elastic modulus of the materials is calibrated to be equal to the modulus of viscoelastic relaxation by a defined function of time in the CHILE model. Subsequently, this work effectuates the two proposed models in a three-dimensional composite laminate structure. Through comparing the two numerical outcomes, it is customary that the residual stress and deformation acquired by the modified model of CHILE conform to those ones assessed through adopting the viscoelastic model.