Computational Investigation of Mechanical properties in multi-materials produced by Additive Manufacturing

Abstract

This thesis presents a comprehensive computational investigation into the mechanical behavior of multi-material components fabricated by Wire Arc Additive Manufacturing (WAAM). The study focuses on the combination of two widely used materials—ER70S-6 (a high-strength carbon steel) and SS316L (a corrosion-resistant stainless steel)—to explore the influence of stacking sequence, material interfaces, and transition zones on the tensile properties of bimetallic structures. Finite Element Analysis (FEA) simulations were conducted using Abaqus to evaluate force-displacement and stress-strain responses of both single-material and multi-material specimens. Nine different multi-material specimens were modeled with varying material stacking configurations, with and without transition zones. The simulations revealed that symmetric stacking with strategically placed transition layers significantly enhances tensile performance by promoting uniform stress distribution and delaying fracture initiation. Specimens with abrupt or asymmetric interfaces exhibited higher stress concentrations, leading to premature failure. Fracture typically initiated near interface regions, highlighting the critical role of inter facial design in structural integrity. The study also established a robust simulation workflow on CSC Puhti, enabling high-performance computation for complex WAAM geometries. The results provide valuable insights into optimizing material arrangements for tailored mechanical behavior in additive manufacturing. This research lays the foundation for future experimental validation and advanced modeling of functionally graded materials, residual stress, and fatigue behavior in multi-material WAAM components.