压弯剪扭作用下异形柱的抗扭性能研究

为研究复合受力下异形柱的抗扭性能, 进行了一根L形柱、四根T形柱和一根十字形柱在压弯剪扭复合受力下抗扭性能的试验研究, 分析了轴压比、扭剪比、截面形状对异形柱抗扭性能的影响情况. 利用有限元软件建立了复合受力下异形柱抗扭性能的数值分析模型, 建议了相应的模型分析参数. 研究结果表明：在试验参数范围内, 轴压比和扭剪比会提高T形柱的抗扭性能. 轴压比为0.314的T形柱的极限扭矩和极限扭转角比轴压比为0.114的提高了203.8%和41.7%. 扭剪比为1.34的T形柱的极限扭矩和极限扭转角比扭剪比为0.57的提高了62.9%和112.5%. 截面形状对压弯剪扭复合受力下异形柱的开裂扭矩、极限扭矩的影响规律较复杂. 建立的有限元模型能够较准确的模拟压弯剪扭作用下异形柱的开裂扭矩和极限扭矩.

STUDY ON THE TORSION PERFORMANCES OF CONCRETE SPECIALLY SHAPED COLUMNS UNDER THE ACTIONS OF COMPRESSION,BENDING, SHEAR AND TORSION

One L-shaped column, four T-shaped columns and one +-shaped column were tested under the combined actions of compression, bending, shear and torsion to investigate their torsion performances. The influence of axial load ratio, torsion-shear ratio and sectional shape on the torsion behavior of specially shaped columns was analyzed. The numerical model for the torsion performances of specially shaped columns under the combined actions was established by finite element software, and the corresponding model parameters were suggested. The results show that within the scope of test parameters, the torsion performances of T-shaped columns are increased with axial load ratios and with torsion-shear ratios. With the increase of axial load ratios from 0.114 to 0.314, the ultimate torque and the ultimate torsion angle of T-shaped column are increased by 203.8% and 41.7%. With the increase of torsion-shear ratios from 0.57 to 1.34, the ultimate torque and the ultimate torsion angle of T-shaped column are increased by 62.9% and 112.5%. The effect of sectional shape on the cracking torque and the ultimate torque of specially shaped columns is complicated. The cracking torque and the ultimate torque are well predicted by the proposed finite element model.