骨组织是一种结构极为复杂的生物复合材料，其在生活中经常受到冲击载荷的作用而导致骨折，骨组织的冲击损伤对人体健康也具有重大意义。本项目针对目前骨冲击损伤理论模型简单无法反映骨各向异性多尺度损伤的问题，基于多尺度的实验观察，在骨单元内和骨单元间两个尺度建立损伤本构和演化方程；利用多手段的实验方法对骨的两尺度损伤力学行为进行观测，通过实验识别不同尺度的损伤模型参数；选取合适的损伤变量，建立骨在冲击载荷下的损伤力学本构模型；最后基于新建立的损伤力学模型，模拟一些典型的与骨损伤有关的临床案例，验证模型的有效性和可靠性。本项目从具体的骨材料结构特点出发，结合现代实验技术手段验证与补充的研究方法，可以推动细观损伤力学理论与方法在骨的冲击损伤领域得到更好地应用，使对骨冲击损伤的定量理论描述更加精确。

The damage behavior of bone is very difficult to the researchers due to its complex hierarchical composite of collagen and hydroxyapatite. Currently the study of damage is a very active field; many experimental studies have been undertaken in recent years, showing, for example, that damage can be linked to reduced stiffness, to ageing in humans and animals and to osteoporosis and its treatment..Most recent researches in this field are about the quasi-static mode. While the impact loadings are very common in our normal life. The study in this field should be pushed in the future. In this project, multi-experimental method is utilized to reveal how the complex structure is imbued with mechanisms to resist fracture at different size scales by increasing energy dissipation when the bone subjects to the impact loadings. The results will be compared to the damage modes of hydroxyapatite and carbon fiber composites. Then a new damage model is established to rationalize the damage evolution law of bone under simultaneously applied complicated compact loads. Some crucial physical and biological mechanisms underlying the sophisticated damage process of bone tissues have been incorporated in the model. Especially, an evolutionary law of bone damage is presented to analyze the complicated damage behavior of bone due to its anisotropy and complicated composite structures. The new proposed model can be used to predict the fracture risk of damaged bone under impact loadings and the results do suggest some clinical uses in the future.