Abstract: Underwater pipes and pipelines are laid on the seabed for a long period of time， including pipelines and cables on the seabed. The seabed is subject to currents， tides and waves， which bring silt， sand and gravel， changing the geomorphology of the seabed and the morphology of the seabed around the pipelines. These changes and deposits cause damage to submarine pipelines and cables. To minimize these damages， the placement of new polymer composite protective mats is often used to cover structures such as submarine pipes and cables. In this study， a novel underwater placement device is proposed， for which full system design， system development and testing have been carried out with the aim of solving the problems of high cost， low efficiency and poor economic efficiency of the existing repair methods. In this paper， the static analysis of the model is carried out by using NX Nastran solver，  after the finite element static analysis by NX Nastran solver. The results of the frame structure calculation of the deployment device are then postprocessed and analyzed by Femap software to study the two working conditions of the underwater operation and surface deployment. The results show that the deployment device meets the structural design requirements， and also provides important data for optimizing the structure of the device.

Key words: fabric lifting device, NX Nastran, Femap, finite element analysis, structural strength