Finite Element Analysis of the Strength of Ladder Type Structure of the Deep-Water AUV

Autonomous underwater vehicle (AUV) is one of the current research hotspots in the field of robotics. It has abroad application prospect in the oceanographic survey, resource exploration and military fields. The AUV presented in this paper is mainly used for investigating the deep water oil and gas resources and works in underwater 3000 meters. It carries a series of measuring equipment, such as battery, sensors and pressure-resistant cabins, to engage in exploration tasks. When the AUV is lifted in water or in air, the loads acted on the main frame of AUV are different. In order to realize lightweight design and save buoyancy within the allowable range of the material strength, this paper puts forward a novel ladder type construction with two longitudinal beams and five crossbeams made of stainless steel, and analyzes the forces sustained by the main frame when lifted. Compared with traditional aluminum welding structure frames, the advantages of the trapezoid frame of the deep water AUV are as follows: large effective capacity, strong bearing capability and convenient maintenance. At the same time, using GRP hulls can improve the total structural strength significantly. The validity of the design and analyze is verified by recent at-sea trails.