计入骨架层铺设角度、初始椭圆度、材料非线性,对相邻表面分别采用黏结耦合、摩擦系数不为零的库伦摩擦和光滑摩擦S种接触条件,基于ABAQUS研究了一类非黏结柔性立管骨架层在均匀外压和对径压缩力下的失效特性.计算结果表明:骨架层相邻表面间接触条件对失效特性影响较大;铺设角度对骨架层失效特性的影响可忽略不计;计入初始椭圆度和材料非线性后,均匀外压下骨架层临界压溃值大幅降低,对径压缩力下径向位移大幅增大.文中数值方法可弥补理论方法无法计入上述因素对骨架层失效特性影响的缺陷.
In order to investigate the failure property of carcass layer, the lay angle, initial ovality and ma- terial nonlinearity of carcass layer were considered in this paper. Meanwhile, three kinds of contact conditions, i. e, bonded coupling, coulomb friction with friction coefficient, and smooth friction were adopted to simulate the contact between adjacent surfaces of carcass layer. Finally, failure properties of a typical car cass layer of unbonded flexible riser under uniform external pressure and two forces acting along a diameter were predicted by using ABAQUS. It is shown that the contact condition between adjacent surfaces of car- cass layer has a great influence on failure property. The lay angle effect on failure property can be ignored. With initial ovality and material nonlinearity, the critical pressure of carcass layer under uniform external pressure is sharply decreased, while the radial displacement of carcass layer under crushing is greatly in- creased. The numerical method can remedy the flaw of analytical method which cannot take the above fac- tors into consideration.