Advanced Design of Structural Joints for Large Deformations under Earthquake Loading

Structural joints are among the most critical regions in earthquake-resistant buildings because they transfer axial force, shear, bending moment, and torsion between beams, columns, braces,walls, and foundations. Conventional rigid connections are generally designed to prevent collapse through plastic energy dissipation; however, they may experience severe local damage, low-cycle fatigue, connection fracture, and significant residual drift after strong earthquakes.Advanced earthquake-resilient joints use a combination of controlled rocking, post-tensioning, replaceable metallic fuses, friction interfaces, viscous damping, and superelastic shape-memory alloys. The objective is to separate the structural functions of gravity-load resistance, lateral-load resistance, energy dissipation, and self-centering. In this configuration, the main structural members remain predominantly elastic while specially designed joint components undergo stable and replaceable deformation.This paper develops a mathematical and physical framework for the design of high-deformation seismic joints. The formulation combines nonlinear structural dynamics, contact mechanics, frictional dissipation, elastoplasticity, shape-memory-alloy constitutive behavior, fracture mechanics,and thermodynamically consistent hysteresis.