A novel modular system for pipe racks using friction-slip connections

Pipe racks provide essential support for pipelines and equipment in industrial complexes. An innovative modular design method is proposed in this study, where each module is designed to bear gravity and lateral loads independently. To enhance seismic performance, friction-slip connections, consisting of two circular plates bolted to each other and welded to beams and columns, are utilized. A rigid modular pipe rack was modeled in ETABS for structural analysis, and parametric studies were conducted using finite element (FE) models of both rigid and friction-slip connections to evaluate seismic performance. The results showed that friction-slip connections begin slipping at 80 % of the plastic moment of the beams, dissipating earthquake energy through the slipping of circular plates rather than by forming plastic hinges. This mechanism maintains the key structural elements in the elastic zone, avoiding the need to replace beams or columns after earthquakes. Significantly, the system can resume operation by simply unscrewing and retightening bolts. At stiffness values equal to 80 % of a rigid connection, friction-slip connections achieved approximately 80 % of the energy dissipation of rigid connections. Overall, this novel approach to pipe rack design reduces maintenance costs and minimizes downtime after potentially disruptive events like earthquakes.