Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, 5000 West National Avenue, Research 151, Milwaukee, WI 53295; Zablocki Veterans Affairs Medical Center, 5000 W National Avenue, Milwaukee, WI 53295.
Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, 5000 West National Avenue, Research 151, Milwaukee, WI 53295; Department of Neurosurgery, Medical College of Wisconsin, 9200 W Wisconsin Avenue, Milwaukee, WI 53226; Zablocki Veterans Affairs Medical Center, 5000 W National Avenue, Milwaukee, WI 53295.
J Biomech Eng. 2023 Mar 1;145(3). doi: 10.1115/1.4056062.
Body armor is used to protect the human from penetrating injuries, however, in the process of defeating a projectile, the back face of the armor can deform into the wearer at extremely high rates. This deformation can cause a variety of soft and hard tissue injuries. Finite element modeling (FEM) represents one of the best tools to predict injuries from this high-rate compression mechanism. However, the validity of a model is reliant on accurate material properties for biological tissues. In this study, we measured the stress-strain response of thoraco-abdominal tissue during high-rate compression (1000 and 1900 s-1) using a split Hopkinson pressure bar (SHPB). High-rate material properties of porcine adipose, heart, spleen, and stomach tissue were characterized. At a strain rate of 1000 s-1, adipose (E = 4.7 MPa) had the most compliant stress-strain response, followed by spleen (E = 9.6 MPa), and then heart tissue (E = 13.6 MPa). At a strain rate of 1900 s-1, adipose (E = 7.3 MPa) had the most compliant stress-strain response, followed by spleen (E = 10.7 MPa), heart (E = 14.1 MPa), and stomach (E = 32.6 MPa) tissue. Only adipose tissue demonstrated a consistent rate dependence for these high strain rates, with a stiffer response at 1900 s-1 compared to 1000 s-1. However, comparison of all these tissues to previously published quasi-static and intermediate dynamic experiments revealed a strong rate dependence with increasing stress response from quasi-static to dynamic to high strain rates. Together, these findings can be used to develop a more accurate finite element model of high-rate compression injuries.
人体装甲用于保护人体免受穿透性伤害，然而，在击败弹丸的过程中，装甲的背面会以极高的速率变形到穿戴者身上。这种变形会导致各种软、硬组织损伤。有限元建模 (FEM) 是预测这种高速压缩机制造成损伤的最佳工具之一。然而，模型的有效性依赖于生物组织准确的材料特性。在这项研究中，我们使用分离式 Hopkinson 压杆 (SHPB) 测量了高速压缩（1000 和 1900 s-1）过程中胸腹组织的应力-应变响应。猪脂肪、心脏、脾脏和胃组织的高速材料特性得到了表征。在应变率为 1000 s-1 时，脂肪（E=4.7 MPa）的应力-应变响应最具弹性，其次是脾脏（E=9.6 MPa），然后是心脏组织（E=13.6 MPa）。在应变率为 1900 s-1 时，脂肪（E=7.3 MPa）的应力-应变响应最具弹性，其次是脾脏（E=10.7 MPa）、心脏（E=14.1 MPa）和胃（E=32.6 MPa）组织。只有脂肪组织在这些高应变率下表现出一致的速率依赖性，在 1900 s-1 时的响应比 1000 s-1 时更硬。然而，将所有这些组织与之前发表的准静态和中间动态实验进行比较表明，随着应力响应从准静态到动态再到高速率的增加，存在很强的速率依赖性。这些发现可以用于开发更准确的高速压缩损伤有限元模型。
