Compressive properties and parametric study of fiber-reinforced negative stiffness honeycomb with thin-walled inclined beam

Abstract Negative stiffness (NS) honeycombs exhibit exceptional energy absorption and high reusability but face manufacturing limitations due to their complex curved geometries. This study proposes a simplified straight-beam NS honeycomb fabricated via 3D printing using carbon fiber-reinforced polyamide (PA/CF) filaments. By optimizing the beam angles ( θ = 100°–110°), the structure approximates the deformation process and force–displacement response of classical curved-beam NS while achieving 70% higher energy absorption at θ = 100°. Quasi-static cyclic compression tests demonstrated excellent repeatability with 44%–62% energy absorption after four cycles and elastic recovery. Finite element analysis validated the experiments and revealed that the vertical beam thickness dominated the peak force, while the crossbeam stabilized the deformation. These findings suggest that the reusable damping and self-locking effect ( θ > 105°) of NS honeycombs could enable rapid force dissipation in building foundations, and the tunable stiffness with controlled vertical beam thickness energy absorption could also enable applications in biomedical implants (e.g. load-adaptive spinal cages) and surgical tools requiring impact-absorbing precision. Therefore, this work establishes PA/CF-based straight-beam NS honeycombs as scalable solutions for tunable and reusable energy-absorbing devices.