PSI - Issue 58

Yazmin Sahol Hamid et al. / Procedia Structural Integrity 58 (2024) 130–136 Yazmin Sahol Hamid et al. / Structural Integrity Procedia 00 (2019) 000–000

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1. Introduction The use of modular steel structures (MSS) in building construction is gaining popularity due to its innovative techniques, which aim to build homes faster and more efficiently than traditional methods. Many engineers have been inspired to design structures using MSS because it saves money, reduces waste, and speeds up construction (Palmiotta et al. (2022)). This was especially visible during the initial COVID-19 outbreak in Wuhan, China, where MSS played a critical role in rapidly expanding healthcare infrastructure to meet the overwhelming healthcare demand. Two field hospitals with 2,400 beds were built in just 12 days using modular construction techniques, in an impressive display of engineering and construction. This method entailed prefabricating components off-site and assembling them on site, allowing for a quick response to the urgent need for medical facilities (Jeremy Bates et al. (2020)). Various researchers have made significant contributions to the field of modular steel structures. For instance, Dhanapal et al. (2020) introduced a thin-walled hollow structural steel member and the VectorBloc connector. Gapar et al. (2021) explored innovative intra-module connections using hexagonal shapes, while Liu et al. (2015) proposed a bolted-welded joint for high-rise structures. Wang et al. (2016) studied different beam-to-column connections, Yang and Tan (2013) tested bolted joints under column-removal scenarios, and Liu et al. (2017) investigated bolted connection failure mechanisms. Additionally, Morandi et al. (2022) introduced the 'Resisto 5.9,' an external steel reinforcement system with modular steel frames connected by bolts and chemically anchored to masonry. Steel modules are available in various shapes, with the rectangular shape being the predominant choice. Utilizing a modular system presents the inherent benefit of facilitating the creation of distinctive architectural designs, thereby enabling the exploration and implementation of diverse connections within modular constructions. The emphasis on the interconnection of modules in the design of modular steel structures is of utmost importance, as it constitutes a vital element within the realm of prefabricated steel buildings. 2. Structural analysis using SAP2000 In Modular Steel Structures (MSS) design, the intra-modular connection, as shown in Fig. 1a, is a pivotal and foundational element. SAP2000 2.0 was utilized for structural analysis in this research, with several key assumptions. These assumptions include minimal wind loading, brick walls for each primary beam, automatic floor load distribution within SAP2000, similar permanent and variable actions at each floor level, and fixed-to-fixed boundary conditions at each beam-column joint. Fig. 1b visually represents a four-story modular steel structure block with a hexagonal-shaped intra-module connection modeled in SAP2000. The design standard employed for the model was BS EN 1993:1-1 (2005). Table 1 presents the section sizes of the components in the control model, while Table 2 outlines the considerations for loading.

Table 1. Section Sizes of Components in the Control Model. No. Components

Section Sizes

1 2 3 4

Beams Columns

UKPFC 100 x 50 x 10 CHHF 114.3 x 5

Slab – Floor Area Section Slab – Ceiling Area Section

C25/30 with thickness 125 mm C25/30 with thickness 100 mm

Table 2. Loading Consideration in the Structural Analysis. No. Type of Load

Magnitude of Load

Self-weight = Columns, beams and slabs Finishes = 1.2 kN/sq.m Brick wall = 12.5 kN/m

1

Permanent Action

Ceiling Load = 1 kN/sq.m Floor Load = 3 kN/m

2

Variable Action