The irregular distribution of the wave load along the erect riser makes the computation of equivalent wave nodal force difficult when applying Finite Element Method to analyze risers strength.
The final finite-volume discretization equations are derived using the Hamilton principle. Meanwhile the global nodal force vector, mass matrix and tangent stiffness matrix of the cable are obtained.
Equivalent additional stress method can be the same with integral method or combined method depending on the equivalent method of additional nodal force calculated.
等效附加应力法根据附加节点力计算方法的不同分别对应整体式和组合式方法。
Stiffness matrix and equivalent nodal force formula, which take into account of the influence of shear lag, are derived subsequently on the basis of the definition of stiffness coefficient.