FREE VIBRATION ANALYSIS OF CYLINDRICAL AND BOXLIKE ROCKSHAFT BY GENERALIZED CONFIRMING ELEMENT

The cylindrical and boxlike reinforced concrete rockshaft is one of the important and widely used structures in colliery. Due to its complexity, it is rather difficult to acquire its natural frequencies using analytical methods. Although the finite element method is capable of coping with the problem, a large number of degrees of freedom is often needed and the convergence speed is slow. In this paper, a generalized conforming triangular plate element is employed to study the free vibration of cylindrical and boxlike reinforced concrete rockshaft. The present approach is validated by a numerical example. It is shown that the numerical results are in good agreement with those of commercial computer code SAP93 and the experimental data.