A bi-directional metastructure-based joint for static load transmission and multi-directional vibration suppression

• Designed and fabricated a novel joint with TSSD metastructure beam. • Achieves 100% static load transfer before macroslip despite 30% weight increase. • Reduces vibration amplitude by ∼40% under vertical and horizontal excitations. • Nonlinear behavior modeled by six-parameter Iwan model with good accuracy. • Exhibits softening with excitation and hardening with increased bolt preload. In supersonic vehicles, the joint structures between the engine and the airframe must withstand complex static loads and intense vibrations. To achieve the goal of Transmitting Static loads while Suppressing Dynamic loads (TSSD), that is, transmitting lift and thrust while suppressing aerodynamic and engine excitations ,this study designed and fabricated a novel joint with TSSD metastructure beam. Furthermore, a quasi-static test system and a multi-directional vibration experimental setup were developed to investigate the joint’s macroscopic mechanical response and the nonlinear vibration behavior at the joint interface. The results demonstrate that, despite a 30% weight increase, the joint with TSSD metastructure beam can achieve 100% transmission of static loads before macroslip occurs. Meanwhile, the six-parameter Iwan model effectively characterizes the nonlinear hysteresis behavior caused by stick-slip phenomena at the interface. The structure reduces vibration amplitudes by approximately 40% under both vertical and horizontal excitations, with interface slip under horizontal excitation producing a markedly more pronounced nonlinear response. As the excitation amplitude increases, the joint exhibits nonlinear softening, whereas increasing bolt preload induces a nonlinear hardening trend.