Ultimate capacity of cracked tubular T-joints reinforced with grouted clamp connection in axial tension

ABSTRACT

Fatigue-induced cracks are common in tubular joints of aged offshore platforms, especially outlived structures. These joints can be strengthened using grouted clamps or by other means of repair. The design of grouted clamps to strengthen the cracked joints in axial loads especially tensile loads is limited. Hence, experimental and extensive numerical investigations were conducted on the clamped cracked joints under axial tension. The experiments were conducted using a 1:8 scaled model of a typical prototype joint and numerical simulation has been carried out using nonlinear FE analysis based on the modified RIKS method. The ultimate capacity (unclamped and clamped joints) obtained from the numerical model compares reasonably well with that obtained from experiments (Diff.<14%). Parametric assessment on the ultimate capacity of the connection for l_s/d, d_g/t_g, and d_s/t_s has been carried out. The ultimate capacity of clamped cracked joint increases by 76% compared to cracked joint for the l_s/d of 2–3 investigated. The load-displacement behaviour and ultimate capacity of the clamped and unclamped joints are presented and discussed.

KEYWORDS:

• Tubular T-joint
• ultimate capacity
• cracked tubular joint
• grouted clamp
• axial tension load

Acknowledgements

The authors express their gratitude to High performance computing environment at Indian Institute of Technology Madras for access of super cluster using which the numerical simulations were carried out.

Disclosure statement

No potential conflict of interest was reported by the author(s).