A numerical approach to characterize the compression and relaxation behavior of uncured prepreg laminates in the process of hot press-forming

Abstract

In the pre-forming process of uncured prepreg laminates with hot press, the compaction stress is an important parameter that affects the performance and quality of the final product. Therefore, it is necessary to explore the compaction response of the prepreg during manufacturing processes. In this study, the compression and relaxation viscoelastic behaviors of uncured prepreg laminates were investigated in different temperatures, displacements, velocities, and thicknesses. The results show that the power law model and the fractional viscoelastic model could accurately describe the compression and relaxation behaviors, respectively. The theoretical fitting curves match very well with experimental data at each condition and the R-squared value is greater than 0.95. The effect mechanism of compression and relaxation viscoelastic behaviors is analyzed and the obtained results could provide a reference for the process of hot press-forming and numerical simulation.

Keywords

• viscoelastic model
• compression behavior
• relaxation behavior
• uncured prepreg laminates
• hot press-forming