Selective Mesh Conditioning for Stabilisation of Local Non-Linear Response in Finite Element Analysis

In non-linear finite element analysis, the local structural response may exhibit significant sensitivity to spatial discretisation, even when the global structural response remains practically unchanged. Classical h-, p-, and r-adaptive procedures, as well as mesh optimisation and smoothing techniques, are primarily intended to improve mesh quality, solution accuracy, or numerical convergence, rather than to stabilise the local non-linear response while preserving the original computational model. This study presents a Selective Mesh Conditioning (SMC) procedure for selectively stabilising the local non-linear response through conditional nodal relocation without modifying the mesh topology, constitutive models, boundary conditions, contact definitions, or the adopted solution strategy. The procedure is activated by the Percent Error in Structural Energy Norm (SEPC), which identifies regions susceptible to discretisation-induced disturbances, whereas the corrective stage is performed exclusively for admissible nodes using centroid-based nodal relocation. The methodology was evaluated using a three-stage verification framework comprising qualification of the numerical model against four-point bending tests with digital image correlation (DIC) measurements, functional verification using a modified Scordelis–Lo benchmark, and a comparative assessment of the native mesh, classical r-adaptation, and the proposed SMC procedure. The results demonstrate that the proposed procedure selectively modifies discretisation-sensitive local stress and plastic-strain responses while preserving the global structural response. Owing to its non-intrusive implementation, the proposed procedure can be easily incorporated into existing finite element models as a practical tool for stabilising the local non-linear response.