4 - Memorial University of Newfoundland DAI

Chapter 1
Introduction
Tine approach to d-ign in structural engineering could be divided into four
eategoria. Wlcmad, for small structures, where slty is almost inherent
nnd whcre ultimale collapne is unlikely, a heuri~tis sppmaeh is common. In
Lllc second ente@.ry, very common for small structures, tables of data and
caofficiet~ts derived from simplified or semi-empirie~l theories me used in d~
sign. Third, a cmnputer aided approach may be urd for larger and more
complex structure, whore aecurate and sophisticated analyses and theories
nm used. Finally, if the design of an unusual or unique structure is required
(or whem inncc~~atc anslyaes could causecsts.trophicconsequen~), a mm-
puler aided design, combined with amodel testing and analysis appmseh, ia
used.
When littleor no experience hs. been gained fromaimilarexisting struc-
tares, an ~seasmont of the probable dynamic performance is often made.
In such cases, vibration teats an small scale model structures can provide
ih~valuable data. For instance, if no established reliable theoretical appro ad^
mists for the anelyais of particular structural forma (often the ease for re
cently devised systems), if only s limited number of a particular structural
Lypc have been constructed, or if only a short history of the perfomanre has