Dynamic behaviour of axially pre-loaded tubular steel members of offshore structures subjected to impact damage

• Published in: Ocean engineering Vol. 26; no. 10; pp. 963 - 978
• Main Authors: Zeinoddini, M, Harding, J.E, Parke, G.A.R
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.10.1999; Elsevier
• Subjects: Applied sciences; Axial; Building structure; Buildings. Public works; Construction (buildings and works); Damage; Dynamic; Exact sciences and technology; Hydraulic constructions; Impact; Instability; Lateral; Marine; Metal structure; Offshore; Offshore structure (platforms, tanks, etc.); Pre-loading; Ship; Stresses. Safety; Structural analysis. Stresses; Tubular; Impact; Axial; Dynamic; Offshore; Pre-loading; Lateral; Tubular; Instability; Ship; Damage; Metallic structure; Dynamic response; Load distribution; Structure stability; Tubular construction; Lateral distribution; Stationary response; Building functional element; Natural frequency; Impact strength; Failure analysis; Displacement measurement; Numerical simulation; Shipbuilding; Offshore structure
• ISSN: 0029-8018
• DOI: 10.1016/S0029-8018(98)00036-5

The behaviour of an axially pre-loaded cylindrical member of an offshore structure, hit by a supply ship, has been investigated. The effects of axial pre-loading on the dynamic properties of members, the extent of damage and propagation of dynamic instability in the tubular members have also been investigated. Numerical models have been validated using available experimental data from the literature although these are mostly static with no pre-loading. Axial pre-loading was found to change the dynamic characteristics of some cylindrical members quite dramatically while it had no significant effect on others. The study examined whether there was any change in the behaviour between local and global modes when the loading was dynamic rather than static. The effect of damping on the dynamic instability of axially pre-loaded tubes under lateral dynamic loads was also studied. It was observed that for some geometries the quasi-static response can be used to define the boundary between bounded and unbounded dynamic responses. The main contribution of this study, compared with previous investigations reported in the literature, is that both pre-loading and dynamic effects have been included.