Abdominal aortic aneurysm (AAA) is a life-threatening medical condition. Normal abdominal aorta has an inner radius of 8.25 mm and 2.35 mm in thickness under the systolic blood pressure condition (~16 kPa). However, for an AAA patient the radius can reach 16.47 mm (see table on the right, typically a size >3 cm in diameter is considered as having AAA).
Assume there is no external pressure or $P_o = 0$. Also, assume there is no longitudinal load.
Calculate the peak circumferential, radial, and longitudinal stresses inside the aortic wall for a normal person and for the patient, assuming a thick-walled tube model? Where are the locations of those peak stresses?
Also compute the maximum shear stresses.
cardiac phase | pressure kPa | inner radius $r_i$, mm | wall thickness $t$, mm
---|---|---|---
diastole | 10.64 | 14.70 | 2.73
systole | 15.96 | 16.47 | 2.35
Aorta
Normal
AAA
Iliacs