The bulkhead panel produced by gluing steel sheet to a mineral wool is mainly used for the offshore or onshore installations. In general, the mechanical properties of mineral wool are not taken into account when performing structural response analysis. However, the mineral wool could affect structural performance and behavior varying structural loading conditions. The present paper is a sequel to the previous paper (Part I: Experimental Approach for Material Behavior. Park, 2018). In contrast to, Part I, the present paper describes the numerical methodology used to assess the fire performance of fire resistance bulkhead by considering the mechanical properties of mineral wool. The numerical analyses based on the use of the Finite Element Method (FEM) were performed using LS-DYNA software. The thermal and structural analyses were coupled in the same computational run, thus allowing considerable savings in modeling and computing time. The temperature distribution in the bulkhead was obtained by a transient thermal analysis and used to generate the thermal loads in the structural analysis. The difference of structural behavior was studied with and without mechanical properties of mineral wool at static, dynamic, and thermal loading conditions.
The bulkhead panels are composites consisting of two relatively thin steel facings enclosing a relatively thick mineral wool core. The properties required for the steel faces are high stiffness (giving high flexural rigidity), high tensile and compressive strength, impact and wear resistance, environmental resistance (UV, heat, etc.), and surface finish. The properties of primary interest for the mineral wool core are low density and (thermal and sound) insulation (Steponaitis, 2012).
The European standard EN 14509 (European Standard, 2013), or European Recommendations published by the European Convention for Constructional Steelwork (ECCS) and the International Building Council (CIB) do not provide detailed design methods for bulkheads with strongly profiled faces. Determination of the load bearing capacity required for the design of bulkhead panels is to a large degree based on test results.