Finite element modelling and experimental modal testing of a three-dimensional framework

The object of this paper is to develop a finite element model for a 1/10 scale crane rig in the laboratory, so that one may predict the dynamic behaviour of the scale crane rig based on the relevant features of the developed finite element model. To this end, the finite element modelling and experimental modal testing for the 1/10 scale crane rig are first carried out. Two kinds of coupling for the transducer and the tested structure for achieving the better experimental outcome are proposed. The finite element model is then modified, according to the experimental results, using various techniques. It has been found that the new modified finite element model, by replacing the conventional infinite rigidity for the ground-fixed nodes by the appropriate stiffness for the translational and rotational springs, can predict the vibration characteristics of the experimental crane rig with satisfactory accuracy.