Ensuring continuity across non-matching finite element meshes is a persistent challenge in numerical simulation. While conventional mortar methods rely on Lagrange multipliers to enforce interface constraints, they often entail significant computational overhead due to the necessity of complex projections between master and slave surfaces. In this study, we introduce an alternative mortar-like formulation grounded in the Arlequin framework, specifically extending the recent work of Portillo and Romero on embedded structures. Rather than imposing rigid surface-to-surface ties, we conceptualize the interface as an intermediate structural layer that bridges independent 3D subdomains. This approach redefines the coupling problem as a volumetric superposition where the structural degrees of freedom (DOFs) serve as the bridge for field transfer. By employing H1 inner products—a hallmark of the Arlequin method—our formulation guarantees a stable and physically consistent transmission of displacements through the incompatible boundaries. This "structural mortar" provides a natural regularization of the interface, proving exceptionally resilient when joining meshes with high resolution gradients or disparate topologies. Numerical experiments confirm that the proposed scheme preserves optimal convergence properties while circumventing the geometric complexities typically associated with traditional mesh-tying algorithms.