Reference Type:  Journal Article
Record Number: 1
Author: Li, G. Q., Cao, K., Lu , Y. and Jiang, J.
Year: 2017
Title: Effective length factor of columns in non-sway modular steel buildings
Journal: Advanced Steel Construction
Volume: 13
Issue: 4
Pages: 15
Start Page: 412
Short Title: Effective length factor of columns in non-sway modular steel buildings
DOI: 10.18057/IJASC.2017.13.4.6
Keywords: Effective length factor, column buckling, semi-rigid connection, non-sway modular steel building, simplified method
Abstract: Prefabrication by off-site manufacturing (OSM) leads to faster construction, improved quality, and reduced resources and waste. As a specific type of off-site structure, modular steel buildings consisting of volumetric modular units is a relatively new structural form in comparison with traditional steel frames with fixed or flexible beam-to-column connections. For multi-strorey modular steel buildings, additional lateral force-resisting systems are commonly used to prevent the structural side sway. In order to rationally evaluate the stability of columns in the non-sway modular steel buildings, the governing equations for determining the effective length factor (K-factor) of columns are derived using the three-column sub-assemblage model. A simplified method based on the French rule is proposed to determine K-factors. Its accuracy and effectiveness are verified against governing equations (maximum error within 6%) and finite element simulation of a six-storey modular steel frame (maximum error within 9%). The influencing factors on the K-factor are studied. The results show that the available methods such as the alignment chart and French rule cannot be directly applied to determine K-factors for the modular steel buildings. It is found that the boundary restraint parameters and their relative values affect the K-factor. The assumption of pinned connections between modular units is found to be non-conservative. It is recommended to check and strengthen the flexible connections for the design of modular steel buildings with too small or too large relative stiffness of the connections between modules.
Author Address: College of Civil Engineering, Tongji University, Shanghai 200092, PR China