Second-order analysis and design of steel scaffold using multiple Eigen-imperfection modes

Casualties due to scaffold collapse are common in many countries. However, current design of scaffolds still mainly relies on experimental results and judgement, which are non-scientific, uncertain and unreliable. From experience, lack of fit at joints between scaffold members greatly affects their buckling strength, implying that initial imperfection is an important factor influencing the overall buckling strength of scaffolds. This paper proposes a design approach that uses multiple eigen-buckling modes as initial imperfections in order to simulate imperfection due to lack of fit or crooked members.