Dynamic Compressive Behavior of a Novel Bioinspired Gradient Negative Poisson's Ratio Sign-Switching Metamaterial...

Area of Science:

• Materials Science
• Mechanical Engineering
• Biomimetics

Background:

• The Scylla serrata crab inspires a new class of metamaterials.
• Negative Poisson's ratio (NPR) materials exhibit unique deformation behaviors.
• Metamaterials offer tunable mechanical properties through structural design.

Purpose of the Study:

• To design and analyze novel thermoplastic polyurethane (TPU) metamaterials with sign-switching negative Poisson's ratio.
• To investigate the quasi-static and dynamic compression behavior of original (OPSM) and gradient (GPSM) structures.
• To explore the influence of gradient characteristics and loading velocities on mechanical performance.

Main Methods:

• Development of original and gradient metamaterial structures (OPSM and GPSM).
• Numerical simulations using finite element analysis (FEA) to model elastoplastic, rate-dependent, and nonlinear contact behaviors.
• Constitutive modeling with neo-Hookean hyperelasticity and Prony series.
• Experimental validation of simulation results.

Main Results:

• The proposed bioinspired metamaterials demonstrate significant negative Poisson's ratio sign-switching characteristics.
• FEA results were validated by experimental data, confirming model accuracy.
• Parametric studies revealed the impact of gradient design and loading speed on mechanical responses.

Conclusions:

• The novel bioinspired metamaterial exhibits fascinating mechanical properties and NPR sign-switching behavior.
• The study provides design guidance for developing and applying advanced bioinspired structural materials.
• These metamaterials hold potential for applications requiring tunable mechanical responses.