Column-based programmable damper for impact protection and vibration suppression of jacket structures

Steel jacket structures subjected to environmental impacts exhibit severe dynamic responses, potentially causing local fatigue failure, plastic damage, and even catastrophic collapse. Therefore, a structure with adjustable stiffness and large damping is ideal for coping with complex environmental loads and dissipating kinetic energy. A novel programmable damper was designed by connecting N-layer coupling elements composed of a linear spring, wire ropes, and an asymmetric column. Analytical models for the elastic buckling behavior of the damper were derived and mutually verified with finite element analysis (FEA). Based on the analytical models, the dependence of the mechanical responses of the damper on the number of elements and the spring stiffness was investigated for design guidance. The results indicate that the N-layer damper has 2^N different stiffnesses, and the total dissipation capacity increases by approximately 2.6N times compared with a single asymmetric column. For potential applications, the dynamic decay responses of representative jacket structures assembled with the damper were simulated using the FE software ABAQUS combined with user-defined-material (UMAT) code, which demonstrated that the programmable damper is an advanced device that simultaneously achieves adjustable stiffness and significant damping.