[Paper Review] Innovative seismic isolation devices based on lattice materials: A review

Fernando Fraternali, Ada Amendola+1 more|arXiv (Cornell University)|Apr 5, 2021

Cellular and Composite Structures36 references18 citations

TL;DR

This paper reviews pentamode lattice-based seismic isolation devices that use alternating layers of lattice materials and stiffening plates to achieve near-zero shear stiffness and high vertical stiffness. Fabricated via 3D printing, these devices demonstrate effective energy dissipation and damping under combined compression and shear, making them promising for low-cost, high-performance earthquake protection systems.

ABSTRACT

This paper reviews recent literature results on the mechanics of structures formed by layers of pentamode lattices alternating with stiffening plates, which can be effectively employed for the development of seismic isolation devices and vibration attenuation tools, with nearly complete band gaps for shear waves. It is shown that such structures, named pentamode bearings, can respond either in the stretching-dominated regime, or in the bending-dominated regime, depending on the nature of the joints connecting the different members. Their response is characterized by high vertical stiffness and theoretically zero shear stiffness in the stretching dominated regime, or considerably low values of such a quantity in the bending dominated regime. Available results on the experimental response of 3d printed models to combined compression and shear loading highlight that the examined structures are able to exhibit energy dissipation capacity and effective damping that are suitable for seismic isolation devices. Their fabrication does not necessarily require heavy industry, and expensive materials, being possible with ordinary 3-D printers.

Motivation & Objective

• To investigate the mechanical behavior of lattice-based seismic isolation devices using pentamode lattices and stiffening plates.
• To analyze the transition between stretching-dominated and bending-dominated deformation regimes in these structures.
• To evaluate the energy dissipation and damping capacity of 3D-printed prototypes under combined compression and shear loading.
• To demonstrate the feasibility of manufacturing such devices using standard 3D printing technology without requiring heavy industry or expensive materials.

Proposed method

• The study analyzes the structural mechanics of periodic lattice materials with pentamode behavior, where the lattice geometry enables near-zero shear stiffness in the stretching-dominated regime.
• The response of the lattice-plate systems is modeled as either stretching- or bending-dominated based on joint flexibility, with key mechanical properties derived from structural mechanics principles.
• Experimental validation is performed using 3D-printed models subjected to combined compression and shear loading to assess stiffness, damping, and energy dissipation.
• The design leverages additive manufacturing to fabricate complex lattice geometries with controlled joint behavior, enabling tunable mechanical response.
• Theoretical analysis includes the derivation of effective elastic moduli and band gap characteristics for shear waves in periodic lattice systems.
• Numerical and experimental results are compared to validate the mechanical model and assess real-world performance.

Experimental results

Research questions

• RQ1 How do the mechanical properties of pentamode lattice-plate structures vary between stretching-dominated and bending-dominated deformation regimes?
• RQ2 What is the energy dissipation capacity of 3D-printed lattice-based seismic isolators under combined compression and shear loading?
• RQ3 Can these devices achieve near-zero shear stiffness while maintaining high vertical stiffness, as required for effective seismic isolation?
• RQ4 To what extent can standard 3D printing technology produce functional seismic isolation devices without specialized materials or industrial infrastructure?
• RQ5 What is the role of joint flexibility in determining the dominant deformation mode and overall dynamic response of the lattice system?

Key findings

• Pentamode lattice-plate structures exhibit theoretically zero shear stiffness in the stretching-dominated regime, enabling effective seismic isolation.
• In the bending-dominated regime, shear stiffness remains significantly low, maintaining suitability for vibration isolation.
• 3D-printed prototypes demonstrate measurable energy dissipation and effective damping under combined compression and shear loading.
• The devices achieve high vertical stiffness while maintaining low horizontal stiffness, a key requirement for seismic isolators.
• Fabrication using standard 3D printers is feasible, eliminating the need for heavy industry or expensive materials.
• Theoretical predictions of band gaps for shear waves align with observed dynamic behavior, confirming the potential for vibration attenuation.