Frictional contact modeling within a local strain-based peridynamic framework for impact-induced failure of 3D-printed concrete

Capturing the dynamic response of 3D-printed concrete (3DPC) remains challenging due to its layered architecture and interface-dominated failure mechanisms, which are difficult to represent using conventional continuum formulations. This paper presents an adaptive frictional-contact formulation within a local strain-based peridynamic (PD) framework for simulating impact-induced damage and perforation in 3DPC. The proposed approach addresses three major limitations of existing PD contact models. (1) To overcome the absence of a robust contact-normal definition in PD, an intrinsically nonlocal procedure is introduced that employs an adaptive weighting scheme to construct outward normals on contact surfaces. (2) To remedy the unphysical stiffness representations used in prior work, a three-dimensional PD contact stiffness is derived based on its classical contact-mechanics counterparts. (3) A general strategy for defining and evolving friction is proposed to capture realistic contact responses. The method is verified through benchmark problems designed to isolate frictional-contact behavior and is validated against experimental compression tests on 3DPC and perforation tests on concrete slabs, achieving accurate predictions of failure patterns. A case study on hollow 3DPC cylinders further demonstrates the framework’s capability to resolve interfacial failure modes inherent to layer-wise deposition. Overall, the proposed nonlocal frictional-contact formulation provides a robust computational tool for dynamic failure analysis and establishes a foundation for developing standardized impact-characterization protocols for 3D-printed cementitious materials.