The Structural Design and Optimization for the Inner-Frame of Subsea Flange Connection Tool

Abstract

Subsea Flange Connection Tool (SFCT) is a remote apparatus for connecting underwater bolted flanges, especially applied in the offshore pipeline laying. As a pivotal unit construction of SFCT, Inner-frame enables the Bolt Handling Tool and Nut Handling Tool to move separately in axial direction and together in circumferential direction with the reference of the pipe’s axes. This paper presents the Inner-frame’s structural concept and builds its kinematics-equivalent mechanism models, carrying on the kinematics analysis of Inner-frame; to improve the energy efficiency, models the Inner-frame’s rotation-mechanism parametrically and establishes an objective with the minimum power consumption, which generates the optimal positions for the hinged-hydraulic cylinder’s joints with Box and Pendulum.