电除尘器中一双肢超宽截面柱轴压稳定性研究

STABILITY OF AN EXTRA WIDE COLUMN COMPOSED OF DOUBLE LIMBS IN ELECTROSTATIC PRECIPITATOR UNDER AXIAL COMPRESSION

某大型电除尘器壳体内设有一非常规截面轴心受压柱,由于其截面和构造的特殊性,立柱绕强轴的稳定性无法按照现行规范设计。通过非线性有限元方法,考虑初始几何缺陷和焊接残余应力影响,研究立柱承受轴向压力时绕强轴的稳定性。结果表明,立柱不会发生绕强轴的弯曲失稳,而是表现为弹塑性弯扭失稳。两肢间连接槽钢和连接腹板上加劲角钢增强时,稳定性有很小幅度的提高。连接腹板宽厚比增大,稳定性明显变差。在保持H型钢柱绕强轴长细比不变时,稳定性随着H型钢柱腹板高厚比的增大而增强。根据大量计算结果,通过数值回归,提出此种截面柱绕强轴稳定承载力的计算建议,并提出使立柱截面设计更为经济合理的连接腹板宽厚比的设计方法。

An unusual shaped column subjected to axial compression is located inside the casing of a large scale electrostatic precipitator .Because of the peculiarity of section and configuration of the column , its stability design round strong axis can ’ t comply with the current structural specification .In consideration of initial geometrical imperfections and weld residual stresses , the investigation into stability round the strong axis of column by nonlinear finite element method is conducted .The research results indicate that the column doesn ’ t present the flexural buckling round the strong axis , but presents the elasto-plastic flexural-torsional buckling .The stability increases slightly when the connecting channel shaped steel members between two limbs and the stiffeners located on connecting web are strengthened .The stability is weakened significantly when the width-thickness ratio of connecting web increases.When the slenderness of H shaped steel round the strong axis is kept constant and the height -thickness ratio of H shaped steel web increases , the stability increases .Based on a great many computation results , the evaluation recommendation is proposed for the buckling bearing capacity of column under axial compression round strong axis by numerical regression , and the design method of economical width-thickness ratio of connecting web is proposed.