Dynamic Analysis of Cranes

The objective of this paper is to analyze the crane structures as a step to study their effects on the structures working integrally with them. The interaction between cranes and those structures has dominant effects on the global system behavior. Crane structures may have many forms of space structures. It is not logical or economical to perform experimental modal analysis to all of them to investigate the structural behavior of such structures and carry out the in-site tests of measuring their effects on the structures integral with them. In this paper a trial is made to estimate the crane structure’s eigenpairs numerically on the basis of finite element methods, The finite element method was applied firstly on a small space structure. Small space slightly complicated structure is designed, manufactured and dynamically analyzed experimentally and analytically to validate the model. The results indicate good agreement between theoretical and experimental eigepairs. An in-site crane is analyzed on the basis of the refmed model. The results of the analytical study and measured frequencies indicated that there is some coincidence between exciting frequencies and system natural frequencies. Crane/barrage interaction was analyzed and the deflections in the barrage structure were theoretically predicted by using the m-site crane eigenpairs and reactions between the crane and the barrage structure in a trial to reduce their hazards on the masonry structures. The results indicated that high inning speeds cause less deflection but they still serious because they cause dynamic fluctuation along their track. Running speeds of cranes on such structores are recommended. NOMONCLATURE: N : number of modes. [!a [cl w4~1 : mass, damping, stiffness and modal shape matrices.