A New Formulation for Predicting the Collision Damage of Steel Stiffened Cylinders Subjected to Dynamic Lateral Mass Impact

Abstract

The objective of this study is to develop a new formulation for predicting the permanent local denting damage of steel ring and/or stringer-stiffened cylinders under dynamic lateral mass impact. The considered scenarios could represent the collisions of offshore cylindrical structures with bow or stern of service vessels or floating objects. Before deriving the formulations, the numerical methods were developed using ABAQUS/Explicit to determine the deformation of these stiffened cylinder structures subjected to dynamic lateral mass impact. Next, rigorous parametric studies were performed on the actual design full-scaled stiffened cylinder examples using the developed numerical method. Based on the rigorous numerical results, new simple design formulations to predict the maximum permanent local dent depth of a stiffened cylinder are derived through a regression study as the function of a non-dimensional energy parameter. The accuracy and reliability of the derived formulations are confirmed by comparison with the available test results, nonlinear FEA and existing analytical, and empirical equations in the literature. A good agreement with existing test data for ship-offshore structure collisions was achieved.

Numerical studies on residual strength of dented tension leg platforms under compressive load

“…The dimensions and material properties of the model are listed in Table 1. It is noted that the accuracy and reliability of developed numerical techniques have been validated and given in references [15][16][17][18][19][20][21]24] by the author. Therefore, in this study, the numerical method is only focused on the explanation of case study models.…”

“…The contact between striker header shape and cylindrical shell surface was determined by general contact with penalty approach. The friction coefficient at contact area was defined with 0.3 [24].…”

“…(10)- (17). The details of deriving formulation procedures to the maximum permanent dent depth of stringer-stiffened cylinders can be found in Do et al [24].…”

Deriving formulations for forecasting the ultimate strength of locally dented ring-stiffened cylinders under combined axial compression and radial pressure loads

“…1-12. The details of derived formulation procedures to assess the per- manent dent depth of ring-stiffened cylinders is given in reference Do et al 22 .…”

“…Nowadays, nonlinear finite element methods (NFEM) are great tools to forecast ship and offshore cylinder structural collisions. It is also the convenience and economic efficiency to perform the full scale of reality structures where all boundary conditions and material properties can be included [20][21][22] . Therefore, the best way to evaluate the ultimate strength after collisions between ship and offshore cylinders is carefully performed the NFEM.…”