Gibbons Melissa M, Dang Xinglai, Adkins Mark, Powell Brian, Chan Philemon
J Biomech Eng. 2015 Apr;137(4):041002. doi: 10.1115/1.4029181. Epub 2015 Feb 5.
A detailed 3D finite element model (FEM) of the sheep thorax was developed to predict heterogeneous and volumetric lung injury due to blast. A shared node mesh of the sheep thorax was constructed from a computed tomography (CT) scan of a sheep cadaver, and while most material properties were taken from literature, an elastic-plastic material model was used for the ribs based on three-point bending experiments performed on sheep rib specimens. Anesthetized sheep were blasted in an enclosure, and blast overpressure data were collected using the blast test device (BTD), while surface lung injury was quantified during necropsy. Matching blasts were simulated using the sheep thorax FEM. Surface lung injury in the FEM was matched to pathology reports by setting a threshold value of the scalar output termed the strain product (maximum value of the dot product of strain and strain-rate vectors over all simulation time) in the surface elements. Volumetric lung injury was quantified by applying the threshold value to all elements in the model lungs, and a correlation was found between predicted volumetric injury and measured postblast lung weights. All predictions are made for the left and right lungs separately. This work represents a significant step toward the prediction of localized and heterogeneous blast lung injury, as well as volumetric injury, which was not recorded during field testing for sheep.
开发了一个详细的绵羊胸部三维有限元模型（FEM），以预测爆炸导致的异质性和容积性肺损伤。从一只绵羊尸体的计算机断层扫描（CT）构建了绵羊胸部的共享节点网格，虽然大多数材料属性取自文献，但基于对绵羊肋骨标本进行的三点弯曲实验，对肋骨使用了弹塑性材料模型。将麻醉的绵羊置于一个围栏中进行爆炸，使用爆炸测试装置（BTD）收集爆炸超压数据，同时在尸检期间对表面肺损伤进行量化。使用绵羊胸部有限元模型模拟匹配的爆炸。通过在表面单元中设置标量输出（称为应变乘积，即所有模拟时间内应变和应变率向量点积的最大值）的阈值，将有限元模型中的表面肺损伤与病理报告进行匹配。通过将阈值应用于模型肺中的所有单元来量化容积性肺损伤，并发现预测的容积性损伤与爆炸后测量的肺重量之间存在相关性。所有预测均分别针对左肺和右肺进行。这项工作朝着预测局部和异质性爆炸肺损伤以及容积性损伤迈出了重要一步，而容积性损伤在绵羊的现场测试中并未记录。
