A Hybrid SDOF Model for Thin Steel Plates Under Dust-Explosion Loading: Dynamic Response and Preliminary Collapse Assessment

Dust explosions represent a major hazard in industrial environments where combustible powders are generated, handled, transported, or stored. In partially or fully confined equipment, the rapid pressure rise associated with dust deflagrations may impose severe impulsive loads on thin-walled steel components such as panels, walls, covers, and closure elements. Under these conditions, the structural response may evolve from bending-dominated behavior to a strongly nonlinear regime in which membrane effects become significant and classical linear formulations are no longer adequate. This paper proposes a hybrid single-degree-of-freedom (SDOF) model for the rapid prediction of the dynamic response of thin steel plates subjected to pressure-time histories representative of dust-explosion scenarios. The proposed formulation combines an elastic branch enhanced by a membrane-stiffness contribution with a subsequent global elastic-plastic branch, enabling efficient simulation of displacement-time histories with limited computational effort. In addition, a preliminary collapse-oriented classification is introduced to identify response regimes compatible with large plastic deformation, tensile tearing and shear-sensitive behavior. The model is conceived as a fast-engineering tool for preliminary assessment, parametric studies and early-stage design. The proposed approach provides a physically informed link between dust-explosion load definition, nonlinear plate response and simplified collapse interpretation.