Improved discrete element method for linear and nonlinear dynamic analysis of 3-D beam structures

Based on the combination of multi-body dynamics and structural dynamics, a new model of discrete element with flexible connector is developed. It is applicable to the eigenfrequency and geometric nonlinear dynamic response analysis of three-dimensional beam structures. It is pointed out that both the generalized elastic coefficient matrix of the flexible connector and the mass matrix of discrete element may be off-diagonal in a general case. A special discrete element, zero-length rigid element, is introduced to simulate the node at which multiple elements are jointed together. It may also be efficient when the axes of adjacent elements are not in the same line. The formulation of stiffness matrix is established while nonlinearity is taken into consideration. Given examples show that the model is successful in eigenvalue calculation and geometric nonlinear response analysis.