Reducing Stress Concentration Around a Hole in a Thin-Wall Cylinder Subjected to Internal Pressure Using Piezoelectric Patches

Abstract

Decreasing stress in a part or piece of equipment especially in a stress concentration point without increasing thickness or using stronger material is always an interesting issue for design engineers. In this paper, piezoelectric patches were used for stress concentration reduction around various hole sizes in thin-walled cylindrical shells subjected to internal pressure. Applied voltage to piezoelectric patches induces strain on both patch and part and alters stress flow on the part, leading to new distribution of stresses. Three dimensionless effective parameters that include hole and shell diameters as well as shell and piezo patch thicknesses were selected in this investigation. Ant colony optimization was utilized, and attachment of optimal arrangements of piezoelectric patches was derived for various numbers of piezoelectric patches. Using finite element analysis, it was shown that various combinations of these dimensionless parameters (R/t, tp/t and d/D) have different effects on reducing the maximum stress around the hole and up to 20% reduction on maximum stress was achieved during this research. Experimental tests were finally performed to verify finite element results.