Dynamics of Coupled Structures, Volume 4: Proceedings of the 41st IMAC, A Conference and Exposition on Structural Dynamics, 2023, the fourth volume of ten from the Conference brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of the Dynamics of Coupled Structures, including papers on: Real-Time/Hybrid Substructuring Transfer Path Analysis Frequency Based Substructuring The Substructuring Benchmark Challenge New Challenges & Approaches in Substructuring.