A 3D model for static and dynamic analysis of an offshore knuckle boom crane

The paper presents a spatial model of a crane consisting of two booms connected by means of a knuckle. Change of the crane radius and position of booms is realised by length change of cylinders. The crane model takes into account flexibility of booms, cylinders and the rope system. The rigid finite element method is used for discretisation of booms. The computer programme developed on the basis of the model presented enables calculations of dynamic and static analysis to be carried out. The software package is used by designers from PROTEA to test the crane during handling operations in conditions at sea. The model has been validated for tasks of lifting the load with a given velocity both from the air and base. Results of numerical simulations are compared with those of experimental measurements on the test stand.