Computational modeling of weld-line impacts on mechanical behavior of fiber-reinforced thermoplastics

Polat A., DELİKTAŞ B., YAZICI M., Voyiadjis G. Z.

European Journal of Mechanics, A/Solids, vol.109, 2025 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 109
  • Publication Date: 2025
  • Doi Number: 10.1016/j.euromechsol.2024.105485
  • Journal Name: European Journal of Mechanics, A/Solids
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), Communication Abstracts, Compendex, INSPEC, Metadex, zbMATH, Civil Engineering Abstracts
  • Keywords: Finite element analysis (FEA), Mold flow simulation, Plastic injection, Thermoplastic composites, Weldline
  • Bursa Uludag University Affiliated: Yes

Abstract

The areas where the weld line is located are weak areas in terms of impact strength and tensile strength, which negatively affects the overall strength of the final product. It can also cause visual defects on the surface and create an aesthetically undesirable situation. The injection molding process introduces anisotropic behaviors in materials, particularly in weld-line areas, which are proned to mechanical weaknesses. This study aims to enhance the predictability of the mechanical performance of injection-molded fiber-reinforced thermoplastic composites (FRPs) through a comprehensive computational modeling technique. By using software such as MOLDEX3D and DIGIMAT RP, this research integrates real-time data on fiber orientation and weld-line effects into the finite element analysis (FEA) models. Simulations of 40% glass fiber reinforced polyamide (PA6) revealed the impact of different gate numbers on mechanical strength, highlighting the influence of weld-line regions. The findings suggest that incorporating fiber orientation and weld-line data significantly improves the accuracy of FEA models, leading to better predictions in the performance of the parts.