Analysis and modelling of the seismic behaviour of high ... - Ingegneria
Analysis and modelling of the seismic behaviour of high ... - Ingegneria
Analysis and modelling of the seismic behaviour of high ... - Ingegneria
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
3. SEISMIC BEHAVIOUR OF BOLTED END PLATE BEAM-TO-COLUMN STEEL JOINTS<br />
RELATIVE ENERGY<br />
0.5<br />
0.4<br />
0.3<br />
0.2<br />
0.1<br />
3.5.2 Coupled Tee Stubs<br />
0<br />
TC-2<br />
TC-3<br />
eu/ey<br />
0 20 40 60 80 100 120 140 160<br />
PARTIAL DUCTILITY<br />
Figure 3.13. Relative dissipated energy vs. partial<br />
ductility for <strong>the</strong> TC-2 <strong>and</strong> TC-3 Isolated Tee stubs<br />
Different inelastic mechanisms were observed in coupled Tee stub tests,<br />
associated with different relative stiffness <strong>and</strong> strength <strong>of</strong> <strong>the</strong> relevant components:<br />
<strong>the</strong> Tee stub, <strong>the</strong> column flange <strong>and</strong> <strong>the</strong> bolts. The total thickness <strong>of</strong> <strong>the</strong> connected<br />
parts; i.e. column flange <strong>and</strong> Tee stub plate, also seems to affect <strong>the</strong> response.<br />
Figure 3.14a compares <strong>the</strong> responses <strong>of</strong> specimens C1A1-2 <strong>and</strong> C1A2-2, different<br />
for <strong>the</strong> column section, which is a HEA180 in <strong>the</strong> former <strong>and</strong> a HEA280 in <strong>the</strong> latter<br />
test. It is apparent that specimen C1A1-2 is characterized by large energy<br />
absorption <strong>and</strong> displacement ductility, due to <strong>the</strong> extensive plastic deformation<br />
occurring in both <strong>the</strong> Tee stub with t = 12mm <strong>and</strong> <strong>the</strong> column flange with tf = 9.5<br />
mm. Failure was attained by brittle fracture <strong>of</strong> <strong>the</strong> Tee stub weld toes after crack<br />
propagation. The C1A2-2 specimen has a thicker column flange, i.e. tf = 13mm,<br />
which caused inelastic phenomena to concentrate in <strong>the</strong> Tee stub only. This results<br />
in lower displacement ductility <strong>and</strong> energy absorption, while pinching phenomena<br />
appear in last cycles. As to <strong>the</strong> corresponding two 18 mm plate thickness<br />
specimens (see Figure 3.14b), specimen C1B1-3 with a HEB180 column section<br />
with tf = 14mm experienced inelastic phenomena in <strong>the</strong> sole column flange, which<br />
resulted in a limited energy absorption <strong>and</strong> maximum displacements capability,<br />
while in <strong>the</strong> specimen C1B2-3 with a HEB280 pr<strong>of</strong>ile <strong>and</strong> tf = 18mm plastic<br />
phenomena occurred both in <strong>the</strong> Tee stub <strong>and</strong> in <strong>the</strong> column flange, enabling<br />
61