Title: Design and contact analysis of gripper for tube inspection robots

Authors: Qi Li; Lili Qian; Weiwei Li; Zhiqiang Zhang

Addresses: School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei, 430072, China ' School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei, 430072, China ' School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei, 430072, China ' School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei, 430072, China

Abstract: Automatic robots have been extensively employed to inspect steam generator (SG) tubes. Positioning and fixation of robots underneath tube-sheet plates are enabled by tube grippers. In this paper, configuration design and performance analysis of a new tube gripper were carried out. To calculate the gripper's load capacity, numerical analysis was used to establish finite element (FE) model of the gripper. Furthermore, orthogonal experiment and statistical methods combined with FE analysis were adopted to explore the influence on contact between the gripper and the tube's inner wall by manufacturing tolerance. Three factors of dimension and form tolerance were selected in sensitivity analysis. The influencing factors of contact stress were analysed by analysis of variance (ANOVA). Physical prototype experiment results were provided to validate the design rationality. Results of analysis and actual tests proved that the gripper with inelastic fingers exhibited excellent load capacity, superior contact performance and longer service life time.

Keywords: new tube-gripping mechanism; payload capacity; FE analysis; statistics; sensitivity analysis; manufacturing tolerance; contact stress distribution.

DOI: 10.1504/IJCSM.2018.094663

International Journal of Computing Science and Mathematics, 2018 Vol.9 No.4, pp.340 - 351

Received: 13 Aug 2017
Accepted: 10 Nov 2017
Published online: 11 Sep 2018 *

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