Material Mechanisms Of Tensile And Fracture Response In The Bovine Aorta

摘要

The arterial wall is a natural composite biomaterial. It is a mixture of elastin and collagen fibers, smooth muscle cells, and a matrix of connective tissue, sometimes called the ground substance. The different component fibers behave differently. Elastin fibers are highly extensible, with a relatively low stiffness. Collagen fibers are less extensible than elastin, with higher stiffness. The smooth muscle cells are visco-elastic, and able to actively contract, in contrast to the passive elastic and collagen fibers. Therefore, different relative amounts, orientations, and compositions of the fibers will directly and significantly change the material's response to loading. Many studies have contributed to the understanding of arterial mechanical behavior. However, there is little information available on arterial response at different locations, or beyond the normal physiological loading regime, as experienced during trauma. For example, arterial behavior up to and including failure, the location of the weakest points of the blood vessels, and the predominant fracture modes remain unknown. Further, there is little understanding of material and microstructural contributions to mechanical behavior. In this study, we investigated the arterial wall's response in tensile and fracture tests and whether the responses were correlated to microstructure.