Ship impact forces on bridge piers and pylons

The paper presents simplified analytical expressions for crushing loads for ships in head-on collisions with bridge piers and pylons. Firstly, a series of axial static crushing experiments with models of bulbous bows are described. Three models of bulbous bows with elliptical cross-sections and different internal longitudinal stiffening systems are tested. The crushing forces and energy absorption are measured and the damage modes are clarified. Numerical calculations based on finite element methods and semi-analytical methods are performed to simulate the tests. The results of the experiments and the numerical calculations are used to derive and verify simplified empirical expressions for the total collision forces for head-on ship collisions against flat walls, empirical expressions for the local contact pressure and, finally, maximum crushing forces during collisions against quays and piled caps, where only the bulbs are crushed.