Helical Auxetic Yarns (HAYs) can be used in a variety of applications from healthcare to blast and impact resistance. This work focuses on the effect of the use of different core materials (e.g. rubber, polyurethane, polytetrafluoroethylene/teflon, polypropylene, polyetheretherketone, polycarbonate, acetal) with a nitinol wire wrap component on the maximum Negative Poisson Ratio (NPR) produced and thus the auxetic performance of Helical Auxetic Yarns (HAYs). From the analytical model, it was found that an acetal core produced the largest NPR when compared to the other six materials. The trend obtained from the experimental tensile tests (validation) correlated closely with the theoretical predictions of the NPR as axial strain was increased. The experimental method presented a maximum NPR at an average axial strain of 0.148 which was close to the strain of 0.155 predicted by theory. However, the maximum experimental NPR was significantly lower than that predicted by the analytical model.

螺旋拉胀纱 (HAY) 可用于从医疗保健到防爆和抗冲击的各种应用。这项工作的重点是使用不同的芯材（例如橡胶、聚氨酯、聚四氟乙烯/聚四氟乙烯、聚丙烯、聚醚醚酮、聚碳酸酯、乙缩醛）和镍钛诺绕线组件对产生的最大负泊松比 (NPR) 的影响，因此螺旋拉胀纱 (HAY) 的拉胀性能。从分析模型中发现，与其他六种材料相比，缩醛核产生的 NPR 最大。随着轴向应变的增加，从实验拉伸试验（验证）中获得的趋势与 NPR 的理论预测密切相关。实验方法在平均轴向应变为 0 时呈现最大 NPR。148 接近理论预测的应变 0.155。然而，最大实验 NPR 显着低于分析模型预测的值。