Title: Structural and economic aspects of the use of semi-rigid joints in steel frames
Abstract: This thesis reports on five main areas as follows:
1. Braced steel frames designed for semi-continuous construction were studied to
determine savings in both cost and weight. Various frame parameters such as the
number of bays, use of grade S355 steel, beam spans, types of connection, and
selection of beam size were investigated. The investigation confirmed that semicontinuous
construction contributes to worthwhile percentage savings on both cost
and weight.
2. Analysis and design of steel unbraced frames bending on both axes were performed
with emphasis on stability and deflection checks. Rules are proposed to improve the
stability and stiffness. For connections to the minor axis, a proposed joint detail is
presented. The performance of the frames was checked for collapse load level at ULS;
deflection limits at SLS were also checked; in both cases using first and second order
analysis. The investigation demonstrated that the frames should be restricted to less
than four storeys.
3. A study on minor axis joints was carried out for flush end plate connections connected
to the column web. Previous experimental results of moment and stiffness were
compared with predicted values. Moment values were predicted using Gomes'
formulae. The stiffness due to the column web was predicted using finite element
analysis. The results showed good agreement between experimental and predicted
values. The study on the connections was extended to their suitability in steel frames
bending about the minor axis; the investigation confirmed that the connections were
not suitable for unbraced wind-moment frames. An equation for prediction of initial
stiffness was nevertheless established for the connection.
4. Steel frames with composite beams designed for minimum wind combined with
maximum gravity load were studied for their performance, taking into account
cracking along the beams. The investigation showed that the frames meet the
requirements of deflection and sustain a load level of 1.0 for ULS. For frames studied
for maximum wind combined with minimum gravity load, the moment capacity of the
joints governed the design which resulted in a deeper beam section.
5. Seven tests were carried out for a new type of shear connector system installed by
compressed air. The aim of the tests was to study the shear capacity and ductility of
the studs. The tests showed that the pins fail due to fracture and the stud systems
needs some improvements to increase the key structural properties.
Publication Year: 1997
Publication Date: 1997-03-01
Language: en
Type: dissertation
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Cited By Count: 16
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