Auxetic frame with programmable strength and stiffness: Design, investigation and perspective

To broaden the family of available matrices for auxetic composites, an auxetic TPU frame with cubic matrix cases is proposed, tested, and optimized. Quasi-static compression was applied to the new structure to investigate its mechanical performance. Verified finite element models were established for demonstrating the programmable strength and stiffness. Except for traditional materials that can be portably filled into auxetic frames, aluminum cubic tubes, as an instance of multiple matrixes, were filled into the frame. The newly fabricated auxetic composite structure was also tested experimentally. Besides, a section on multi-functional perspective and potential applications were given at the end to better illustrate the proposed structure in practice. The optimized auxetic frame can be used alone or with multiple strengthening matrixes in many aspects including energy absorbers and smart sensors.