Analysis On The Mechanical Performance And Structural Design Of Bellow For Underwater Pressure Compensation

The high pressure in deep sea is a common problem for various equipmentsworking in underwater environment and needs to be dealt with first. Pressurecompensation which is one of the main measures is preferred to utilizing at homeand abroad. Bellow is widely used in many kinds of pressure compensation devices.The performance of bellows which is used as a main component of the pressurecompensation device has an influence on overall performance of the whole device.In this dissertation, mechanical performance of U-shaped bellow is studied bymeans of nonlinear finite element method. A static force analysis of the bellowloaded with axial pressure is performed under the assumption of geometricnonlinearity and material nonlinearity. The mechanical properties of bellowworking in deep sea are then discussed. The method for calculating the volumechange of U-shaped bellow after deformation is put forward. Under the assumptionof the compression of liquid, the relationship between the volume change of bellowand the pressure difference of inside and outside part of the equipment and workingdepth of equipment is deduced. The computation process is also provided. As ahydraulic pressure balance element of pressure compensation for the deep-seaoil-filled pressure sensor, U-shaped bellow is taken as example and the relationshipbetween the mechanical performance of U-shaped bellow and the axial stiffness isanalyzed. The effect of various structural parameters including depth, the thicknesson axial stiffness is then investigated. The optimum design is carried out byorthogonal experiment method to obtain better parameters of ripple. Based on thework in present study, a conceptual design of dual bellow structure for pressurecompensation of underwater pressure sensor is proposed which provides referencefor the design of pressure compensation device of underwater pressure sensor.