Buckling failure of titanium-steel composite chimney liner

摘要

Current chimney design divides the system into two distinct components consisting of a structural frame supporting an independent liner. One economic design solution consists of a circular reinforced concrete structure with a composite titanium-steel liner. The composite liner system provides the strength and stiffness of the relatively inexpensive carbon-steel backing to support the relatively expensive but corrosion-resistant thin titanium sheet overlay. However, problems may arise in this type of system, as illustrated by this case study of two coal-fired power plant chimneys. Within months after the power plant was placed in operation, the titanium sheets began to debond from the carbon-steel backing. The investigation into the cause of the chimney liner failure included physical testing of the titanium-steel composite system and metallographic examination of the fusion bond concept and fracture surfaces. A buckling analysis was also performed to identify the primary cause of the problem. Both two-dimensional and three-dimensional finite element method (FEM) analyses confirmed stress concentrations were present at the tips of the fusion bond.