# In-Plane Mechanical Properties of a Tetra-Missing Rib Symmetry Honeycomb

## TL;DR

This paper improves the mechanical performance of tetra-missing rib honeycombs by enhancing their symmetry and analyzing their deformation and energy absorption.

## Contribution

Proposes symmetric tetra-missing rib honeycomb designs to enhance deformation stability and load-bearing capacity.

## Key findings

- Symmetry-enhanced TMRH designs show improved deformation stability and mechanical performance.
- Finite element models validated with experiments reveal better agreement in deformation modes.
- Subunit angle parameters significantly influence stiffness and energy absorption.

## Abstract

Tetra-missing rib honeycombs (TMRHs), characterized by monoclinic geometry, exhibit high elastic stiffness but suffer from poor deformation stability and reduced axial load-bearing capacity, which limit their applicability in energy-absorbing and load-sensitive engineering structures. To address these inherent drawbacks, this study proposes two symmetry-enhanced tetra-missing rib honeycomb configurations through overall axisymmetric design and subunit-level symmetric optimization. A finite element model was established in Abaqus/Explicit and validated against quasi-static compression experiments, demonstrating good agreement in deformation modes and mechanical responses. Systematic numerical investigations were then conducted to compare the mechanical properties and deformation behaviors of three honeycomb layouts, including the conventional TMRH and the proposed symmetric designs. Furthermore, the effects of impact velocity on mechanical performance were examined to evaluate the dynamic response characteristics of the structures. Finally, the influence of subunit angle parameters on the stiffness, energy absorption, and deformation stability of the tetra-missing rib honeycombs was comprehensively analyzed. The results provide insight into the role of symmetry and geometric parameters in improving the mechanical performance of TMRH-based structures and offer guidance for the design of high-performance auxetic honeycombs.