Effect of Density and Thickness of Steel–Steel Composite Metal Foam on Its Full-Scale Torch Fire Response

Abstract

Tank cars carrying hazardous materials require fire and thermal protection to prevent disasters in case of accidents. A material with a combination of improved insulating thermal properties and impact resistance within the tank car skin can mitigate the repercussions of such accidents. Steel–steel composite metal foam (S–S CMF) is a novel material with properties that is being investigated for such applications. It is made up of metallic hollow spheres closely packed together within a metallic matrix. To corroborate the effectiveness of this material for the abovementioned application, a full-scale torch fire test based on the 49 Code of Federal Regulations, Part 179, Appendix B must be conducted on 4 × 4 ft (1219.2 × 1219.2 mm) samples, where they are required to withstand a 30 min high velocity jet fire at 1204 ± 55.6 °C, by not recording a temperature higher than 427 °C on the unexposed side of the samples within 30 min. It is necessary to determine the critical thickness of CMF for which the test would pass; however it would be costly to do this experimentally and thus, a numerical simulation must be conducted to predict the optimum parameters that can address the torch fire requirements. This study outlines the procedure adhered to in modeling the torch fire test and investigates the effect of thickness and density on the thermal response of the S–S CMF. Fire Dynamics Simulator and COMSOL Multiphysics are utilized to compare the one dimesional and three dimensional modeling of S–S CMF response to a full-scale torch fire test. Investigation shows that the thickness and density of the material play a significant role in how it responds under torch fire conditions.