Analysis of mechanics characteristics of deepsea drilling risers

The relatively poor deepsea environmental conditions lead to the complex capacities of the deepsea drilling risers.The strength and stability of the riser can be precisely estimated only by analyzing their mechanics characteristics.Finite element analysis is used to establish a deepsea drilling riser dynamic analysis model under complex marine conditions such as ocean current and wave.During this process,simplified approach to the action modes of ocean current and wave is suggested and it is proposed to ascertain the positive effect of wave by analyzing the forces of riser system under different conditions.It is indicated that the effective depth of wave force is related to the wave height and period,that is,the effective depth of wave force is increasing with increasing wave height and decreasing wave period,and vice versa.In addition,the variation of drilling risers’ stresses and strains at different water depth under the influence of various loading modes is analyzed by the means of finite element analysis software ANSYS,providing a scientific basis for the strength design of deepsea drilling riser columns.