27 4 2011 12 WORLD EARTHQUAKE ENGINEERING Vol. 27 No. 4 Dec. 2011 1007 6069 2011 04 0102 07 1 2 2 1. 710055 2. 266033 4 1 2 ANSYS 2 U442. 5 + 5 A Study on seismic behavior of widened beam flange connections of steel frame MAO Hui 1 2 WANG Yan 2 1. School of Civil Engineering Xi an University of Architecture & Technology Xi an 710055 China 2. School of Civil Engineering Qingdao Technological University Qingdao 266033 China Abstract Based on the experiments of four widened beam flange connection specimens and one traditional joint specimen under low period cyclic loading failure forms and seismic behavior of direct arc widened beam flange connections and welded sideplate connections were studied by ANSYS software such as loaddisplacement hysteretic curve skeleton curve ultimate load ductility and energy dissipation factor etc. The comparability between the results from the analyses and those from the experiments is satisfactory. Results of the research show that through properly designing the section of widened flange the plastic hinge of beams can be effectively moved outward from welded connection area in both arc widened beam flange connections and welded sideplate connections and the two kinds of widened flange beam connections have better ductility bearing capacity and energy dissipation capacity than the traditional connection and may satisfy the demand from current Chinese seismic design code. In addition because the arc widened beam flange connections have simpler conformation and fewer welds at the section of widened beam flange which avoid brittle rapture due to the materials becoming brittle in the weld heataffecting zone they have better seismic property than the welded sideplate connections. Key words widened beam flange connection hysteretic curve seismic behavior finite element analysis 2010 03 01 2010 05 24 51078194 20103721003 1976. Email mh76@ qtech. edu. cn. Email yanwang123@ qtech. edu. cn
4 103 1994 1995 1 2 2 3 4 2 5 4 6 1 7 ANSYS 2 8 1 9 10 2 WF 1 WF 2 2 SP 1 SP 2 1 NBF 1 1 Fig. 1 1 Connection details of specimens 1 Table 1 Specimen sizes and widened flange parameters mm l a l b c d WF 1 50 WF 2 80 90 40 SP 1 50 25 SP 2 80 90 40 25 NBF
104 27 AISC 11 2 ANSYS 4 1 2. 1 Q235 7 2 2. 05 10 5 MPa 0. 3 von Mises 2. 2 20 solid95 2 3 Fig. 2 Stressstrain model of material Fig. 3 3 Finite element models of widenedflange connections 2. 3 y 20% 20% y 1 y 2 4 X Y Z Y X 4 Fig. 4 Loading rule
4 105 3 3. 1 P δ 5 WF1 WF2 SP1 SP2 NBF P δ Fig. 5 5 Hysteretic loops of specimens 6 6 a 6 Fig. 6 Skeleton curves
106 27 3. 2 μ 6 a 0. 85P u 2 Table 2 2 7 Comparison between calculating value and test value of bearing capacity and ductility Py /kn Pu /kn WF 1 107. 8 114. 8 135. 72 141. 85 4. 04 4. 13 WF 2 105. 4 102. 8 130. 34 138. 65 4. 18 4. 17 SP 1 109. 5 124. 5 139. 48 157. 95 3. 68 3. 75 SP 2 106. 6 115. 2 133. 17 153. 73 3. 89 4. 00 NBF 97. 1 112. 7 118. 00 149. 75 2. 9 2. 27 2 WF 1 WF 2 SP 1 SP 2 NBF 15% 10. 4% 18. 2% 12. 8% 39. 3% 44. 1% 26. 8% 34. 1% 3. 3 h e h e 1 A h e = 1 2πF Δ A F Δ 2 3 Table 3 3 h e Calculations of equivalent viscous damping coefficient WF 1 WF 2 SP 1 SP 2 NBF h e 0. 408 0. 425 0. 424 0. 427 0. 358 3. 4 WF SP 7 0 ~ Δ ± y Mises WF 1
4 107 Fig. 7 7 von Mises Sketch of von Mises stress nephogram and plastic hinge region 1 2Δ ± 1 3Δ ± y y 2 3Δ ± y von Mises 7 a 1 2Δ ± y Mises 2 3Δ + y von Mises 7 b 7 Mises 3 Mises 8 Fig. 8 8 Comparison of failure modes between finite element analysis and experiments
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