Investigation of the compressive mechanical properties of pyramidal lattice structures

Lattice materials have emerged as promising lightweight structures owing to their tunable mechanical properties and inherent structure function integration. We fabricated pyramidal lattice specimens with systematically varied unit cell sizes (L) and strut diameters (d) and combined experimental testing with numerical simulations to investigate material-structure coupling under compressive loading. The conclusion reveals that the dominance of base material versus structural deformation is strain-dependent and can be modulated by the d/L ratio. Five distinct deformation regimes are identified and mapped against the applied strain. Five distinct deformation regimes are base material dominance (ε=0−0.004), structural effect predominance (ε=0.004−0.02), base material dominance (ε=0.02−0.05), coupled interaction during plastic yielding (ε=0.05−0.45) and dominance of base material upon densification (ε>0.45). Equivalent elastic modulus was developed based on the distinct mechanical response mechanisms of pyramidal lattice structures. The established models prove reasonably accurate in characterizing their equivalent mechanical properties. This work establishes a theoretical framework for the rational design of pyramidal lattice structures in lightweight engineering applications.