The Equivalent Sandwich Plate Method (ESPM) is widely employed in structural engineering for space frames due to its high accuracy under room temperature conditions. However, the precision of ESPM calculations diminishes at elevated temperatures, primarily due to increased static indeterminacy and substantial restraint stress on rods caused by thermal expansion. Additionally, the decrease in the elastic modulus of steel leads to significant changes in mechanical properties. This research focuses on various sizes and the overall compliance of regular square pyramid space frame structures, where the overall compliance is defined as the ratio of the central deflection at room temperature to the long span length of the space frame structure. A new deflection formula for ESPM under high temperatures is derived, considering the mechanical and thermal properties of steel. The finite element software is utilized to simulate the deformation of the space frame. Through the calculation of the ratio of Finite Element Method (FEM) results to ESPM, a series of correction coefficients is obtained to enhance the accuracy of ESPM.

View full abstract

The Fire Resistance Verification Method in Japanese Building Standard Law draft version (dFRVM) provides a method for determining the insulation-based fire resistance of composite slabs. Nevertheless, the dFRVM calculation method’s applicability and accuracy have not been thoroughly examined, especially in the current composite slab configuration. In this paper, the accuracy of the dFRVM equation method was evaluated by comparison with experimental data. Consequently, this paper suggests two enhanced expressions to determine the insulation-based fire resistance of composite slabs. One of these expressions (Equation A) is applicable to a broad range of slab geometry in current practice, while the other (Equation B) is applicable to frequently used slab geometry. The proposed expressions were derived from computed fire resistance values obtained through a validated FEM model. The linear regression method was employed to generate simplified equations using two sets of 144 and 30 composite slab configurations for parametric study. The numerical results and experimental data were used to verify the accuracy of the proposed methods. The proposed Equation A produced deviations of less than 20 minutes and Equation B’s deviation was less than 11 minutes for the insulation-based fire resistance of the composite slabs.

View full abstract

Employing a numerical approach to accurately estimate the heat release rate of a wooden pallet fire poses a significant challenge. The complexity of predicting the HRR is further escalated when coupled with the operation of an active fire suppression system. This study aims to utilise Fire Dynamic Simulator 6.9.1 (FDS) to assess the fire growth and peak heat release rate based on the outcomes of a laboratory fire test involving the combustion of wooden pallets with and without the operation of a fire suppression system. This article presents and deliberates on the modelling methodology, which involves the heat release rate per unit area coupled with the ignition temperature method used in FDS to estimate the growth phase and peak heat release rate in both free-burning and suppression environments. Furthermore, this paper examines the influence of various extinguishing coefficients (E-Coefficient) and water droplet size during the operation of the suppression system on the prediction of heat release rate.

View full abstract

The circular economy has attracted considerable interest for many years. In this paper, we first discuss the latest concrete efforts by individual companies to recycle resources and societal trends and explain the high level of public interest in recycling. We then discuss examples of fire accidents in recycling plants as risk factors for promoting recycling. Even with efforts to be environmentally conscious, neglecting safety management processes can lead to environmental strain. We reaffirm the importance of examining the risks associated with the promotion of recycling.

View full abstract