TITLE:
Failure Analysis of an Aluminum Extension Portable Ladder
AUTHORS:
Abdel-Hakim Bouzid
KEYWORDS:
Portable Ladder, Beam Shortening, Columns Axially Restrained, Buckling
JOURNAL NAME:
Materials Sciences and Applications,
Vol.5 No.9,
July
31,
2014
ABSTRACT: The conditions of end
supports of straight ladders are often the cause of major injuries. The firm
and secure ladder ends against instability in general and sliding of the top
and bottom ends in particular are among the check list of most ladder safety
training books and manuals. However, the restraint to the free expansion of a
ladder can cause a catastrophic failure due to buckling even at intermediate
loads and should be presented in the latter as a serious potential hazard. This
paper deals with an investigation of an extension. An analytical structural
model that simulates the buckling behavior of an axially restrained ladder
subjected to static and dynamic loading is developed. It compares two different
ladder end conditions and shows that instability due to buckling can occur
during ascension or descent in the case of an axially restrained ladder. The analytical
results are supported and validated by a finite element model simulation conducted
in parallel. This study may explain the root cause of similar incidents
involving falls from portable ladders worldwide.