DESIGN AND PERFORMANCE ANALYSIS OF COMPRESSION-TORSION COUPLING METAMATERIAL UPON VARIABLE CURVATURE ROD-STRUCTURE

The inclined ligament, serving as a fundamental element in a compression-torsion structure, plays a pivotal role in determining the mechanical characteristics of the entire structural system, in encompassing deformation modes and, in load-bearing capacity. To enhance the performance of such materials, two innovative compression-torsion metamaterial units are introduced upon a curved rod with variable curvature. Through a combination of finite element simulations, of experiments, and of pertinent theoretical discussions, the study delves into the influence of geometric features of the curved rod, the stacking style of compression-torsion units, and other factors on the mechanical performance of this class of metamaterials. The findings reveal that: under identical compression strain, the Type III compression-torsion unit proposed, in comparison to Type I with straight rod connections, can provide a greater torsional angle, specifically generating a 1.26° torsional angle for every one percent of applied strain. The Type II compression-torsion unit shows improved capacity to withstand external forces, being indicative of higher strength, owing to its smooth connections. Both structures surpass the capabilities of conventional straight rod compression-torsion units, underscoring their superior performance. The introduction of this design imparts fresh perspectives for the advancement of subsequent compression-torsion structures in terms of both design and performance.