RESIDUAL-STRESSES IN OSCILLATING THORACIC ARTERIES REDUCE CIRCUMFERENTIAL STRESSES AND STRESS GRADIENTS

The purpose of this paper is to examine the effects of residual stress es and strains in the oscillating arteries on the stress distribution in the vascular wall. We employ a static theory of large elastic defor mations for orthotropic material (Chuong and Fung, 1986, J. biomech. E ngng 108, 189-192) with the acceleration term added to make the theory dynamic. We use the static elastic parameters of residual stresses in our analysis because the dynamic parameters are not available in the literature. Our analysis reveals that the effect of considering the re sidual stresses is to decrease the very large circumferential stresses at the inner wall by 62% and reduces the stress gradient through the arterial wall by 94% compared to the case when residual stresses are i gnored. Thus, because the arteries do contain residual stresses, the c onsequent lower stresses at the inner wall and the reduced stress grad ient may reduce the progression of atheroma. Our computations show tha t the stress gradients do not depend on the heart rate. Copyright (C) 1996 Elsevier Science Ltd.