Free nonlinear vibration of the cable with external damper

The numerical analysis for cable nonlinear vibration with external viscous damper based on explicit integration equation of motion is proposed. The algorithm allows taking into account both the geometry non-linearity of the cable and the non-linearity associated with the damper. There has been made an analysis of free nonlinear vibration to determine the total vibration decrement of the system with damper. The optimal parameters for external viscous damper are determined. There have been obtained dependences for damping system optimal parameters in relation to the reduced damper coordinate.

Two Approaches to the Problem of High-cycle Fatigue of Materials and Structures

Creation of new types of materials and development of new methods aimed at extending the lifetime of structures are two interconnected approaches to solve the problem of metallic structures fatigue. The paper considers a method for estimating the efficiency of damping implemented in metallic structures by means of energy-intensive materials. The results of comparative calculation are given on the ultimate number of transverse vibration cycles in bridge girders. The calculation uses a linear hypothesis of fatigue-caused damage summation and a model of cyclic material degradation. Notable increase of the vibration decrement for foam-filled metallic structures is predicted, with the lifetime of products lengthening as a result.