24 1 2015 2 JOURNAL OF NATURAL DISASTERS Vol. 24 No. 1 Feb. 2015 1004-4574 2015 01-0114 - 09 DOI: 10. 13577 /j. jnd. 2015. 0115 100124 2 CF - Ⅰ CF - ⅡCF - Ⅰ CF - Ⅱ 2 - ABAQUS TU375 A Calculation analysis of eccentric compression behavior of pentagonal CFST mega columns CAO Wanlin XU Mengmeng WU Haipeng DONG Hongying College of Architecture and Civil Engineering Beijing University of Technology Beijing 100124 China Abstract Taking the pentagonal multi-cavity concrete filled steel tubular CFST mega-columns of Dalian International Trade Center building as the prototype eccentric compression performance tests of two mega-column models with different cross-section constructions were carried out in order to investigate the influence of cross-section construction on eccentric compression behavior. Specimen CF-I was a CFST mega-column model with pentagonal quadruple-caved section without reinforcement cage inside and Specimen CF-Ⅱ was that with reinforcement cages inside. The load-bearing capacity load-deformation curves and failure characteristics of two models were obtained and the finite element simulation was carried out based on ABAQUS as well. The results of simulations accord well with the test. In view of this simulations are carried out for analyzing the effects of the thickness of the external steel tubular plates the separator located in the axis of asymmetry and peripheral vertical ribs on eccentric behaviors of columns. The conclusions are drawn that the additional reinforcement cages can improve load-bearing capacity and ductility the increased proportion of bearing capacity and ductility due to the increase of thickness of external plates is greater than that due to the increase of thickness of separator located in the axis of asymmetry and that the damage of specimens are reduced by increasing the thickness of surrounding vertical ribs. 2014-06 - 10 2014-08 - 10 51178010 1954 -. E-mail wlcao@ bjut. edu. cn
1 115 Key words multi-cavity CFST pentagonal cross-sections mega-columns eccentric compressive behavior numerical simulation 117 T L 1 T T T 2 3 L L 4 ANSYS 5 6 L 7-8 1 1. 1 2 1 /5 2 CF - Ⅰ CF - Ⅱ CF - Ⅰ 11. 14% CF - Ⅱ CF - Ⅰ 9Φ6 φ4@ 80 CF - Ⅱ 0. 29% 3000 mm 850 820 mm 250 mm 2 200 mm 1 Fig. 1 1 Design drawing of specimens Q345 C50 51. 11MPa 3. 45 10 4 MPa 1 1
116 23 F y F u ρ E Table 1 1 Mechanical properties of steels F y /MPa F u /MPa ρ /% E /MPa 6 mm 416 528 27. 5 2. 10 10 5 10 mm 409 498 27. 6 2. 12 10 5 12mm φ4 Φ6 1. 2 373 525 27. 4 2. 06 10 5 CF - Ⅱ 260 366 22. 2 1. 96 10 5 CF - Ⅱ 382 582 31. 3 2. 07 10 5 4000t 2 2000kN 2 Fig. 2 2 Photo of test site - 2. 1 2 3 80% CF - Ⅰ CF - Ⅱ 3 Fig. 3 Failure modes of specimens
1 117 2. 2-2 F - U 4 4 1 2 2 CF - Ⅰ 17036. 7kN CF - Ⅱ 18283. 1 kn CF - Ⅱ CF - Ⅰ 7. 3% CF - Ⅱ CF - Ⅰ 2. 3 - Fig. 4 4 - Curves of vertical load vs lateral deflection 5 CF - Ⅰ CF - Ⅱ 5 a 5 1 2 2 1811 10-6 5 Fig. 5 - Load - strain curves 2. 4 2 6 f Z 6 1 2 2 2 4 5 80% 3 3. 1 ABAQUS damaged plasticity
118 23 Fig. 6 6 Lateral deflection distribution 9 - μ 9 ζ x = ε y = σ ε 0 σ 0 x 1 y = 2x - x 2 x > 1 y = σ 0 = 1 + - 0. 0135 μ 2 + 0. 1 μ 24 f' 1 x β( x - 1) η + x. 2 0. [ ( ) ] [ ( ) ] c 45 f' c 3 ε 0 = 1300 + 12. 5 f' c + 1330 + 760 f' c 24-1 μ 0. 2 4 η = 1. 6 + 1. 5 /x β = f ' c 0. 1 5 1. 35 1 + 槡 μ. 6 μ = A s1 f y1 + A s2 f y2 CF - Ⅰ μ = 1. 55 CF - Ⅱ μ = 1. 60 A c f ck f y1 f y2 A s1 A s2 A c f ck f ck = 0. 647f cu k f' c f c ' = 0. 79f cu k f cu k ABAQUS Plasticity - - Tie embed 8 C3D8R S4R T3D2
1 119 3. 2 10 - - 2 2 7 8 9 CF - Ⅰ CF - Ⅱ - Table 2 2 Calculated and experimental results of ultimate bearing capacity of specimens /mm CF - Ⅰ CF - Ⅱ F u /kn N u /kn N u /F u 200 17 036. 7 16 565. 1 0. 972 200 18 283. 1 16 926. 4 0. 926 Fig. 7 7 CF - Ⅰ Calculated and experimental results of Specimen CF - Ⅰ Fig. 8 8 CF - Ⅱ Calculated and experimental results of Specimen CF - Ⅱ 3. 3 3. 3. 1 10 mm 12 mm 12 mm 7 8 10 mm - 10 11 3. 3. 2 8 10 12 mm
120 23 Fig. 10 10 Fig. 9 9 Comparison of skeleton curves CF - Ⅰ Calculated results of specimen CF - Ⅰwith different thicknesses of outer pipes Fig. 11 11 CF - Ⅱ Calculated results of specimen CF - Ⅱwith different thicknesses of outer pipes 10 mm 8 12 mm - 12 3. 3. 3 4 mm 6 mm 6 mm 4 mm 6 mm - 13
曹万林 等 五边形钢管混凝土巨型柱偏压性能计算分析 CA w M w E w O.c 凯 am 模 eo CA.o E案 rg.c 例库 n 第1 期 图 12 Fig 12 不同对称轴分腔隔板厚度试件计算结果 Calculated results of specimens with different thickness steel axis of symmetry 图 13 Fig 13 不同周边竖向肋板厚度试件计算结果 Calculated results of specimens with different thickness vertical ribs 121
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