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 defla-grations 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 hy-brid single-degree-of-freedom (SDOF) model for the rapid prediction of the dynamic response of thin steel plates subjected to pressure-time histories repre-sentative of dust-explosion scenarios. The proposed formulation combines an elastic branch enhanced by a membrane-stiffness contribution with a subse-quent global elastic-plastic branch, enabling efficient simulation of displace-ment-time histories with limited computational effort. In addition, a prelimi-nary 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 as-sessment, 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.