Performance domains of bio-inspired and triangular lattice patterns to optimize the structures' stiffness

Area of Science:

• Mechanical Engineering
• Materials Science
• Computational Mechanics

Background:

• Mass reduction is crucial for mechanical systems, but material removal can compromise performance.
• Stress-driven material removal methods balance mass reduction and mechanical integrity using local parameters.
• Cellular structures, including lattice-based and bio-inspired patterns, are key to these methods.

Purpose of the Study:

• To investigate the influence of local volume fraction and structural anisotropy on the mechanical stiffness of Periodic Stress-Driven Material Removal (PSDMR) structures.
• To compare the performance of bio-inspired (bone-like square and rectangular patterns) and lattice-based strut patterns.
• To identify optimal cellular structure patterns for stress-driven material removal applications.

Main Methods:

• Finite element analysis (FEA) was employed to conduct linear elastic compressive tests.
• Three distinct planar cellular structures were analyzed: a literature-based square bio-inspired pattern, a novel rectangular bio-inspired pattern, and a standard strut-based lattice pattern.
• The relative longitudinal stiffness of each structure was evaluated under varying local volume fraction and anisotropy orientations.

Main Results:

• Each PSDMR pattern demonstrated a specific domain of superior performance.
• The bio-inspired rectangular pattern showed potential for improved stiffness compared to the square pattern in certain configurations.
• The strut-based lattice pattern exhibited distinct performance characteristics influenced by anisotropy.

Conclusions:

• The study highlights that no single PSDMR pattern is universally optimal; performance is context-dependent.
• Identifying the optimal pattern or combination of patterns based on their performance domains can enhance stress-driven material removal methods.
• This research provides a foundation for selecting the most effective cellular structures to improve the performance of mass-reduced mechanical parts.