单箱多室波形钢腹板组合箱梁的腹板剪应力分析

为研究单箱多室波形钢腹板组合箱梁的腹板受力特性，建立了单箱双室和单箱三室波形钢腹板组合梁的有限元模型，并与模型试验结果进行了对比验证。通过有限元分析得到了不同类型的横向对称和偏心荷载作用下各波形钢腹板剪应变的结果，并对单箱多室波形钢腹板组合箱梁各腹板剪应力分布的不均匀现象的特点和原因进行研究。结果表明:集中荷载和均布线荷载的横向作用位置不同时，单箱多室波形钢腹板组合箱梁各腹板的剪应力差异显著，对称荷载作用下的单个腹板实际剪应力与横截面所有腹板平均剪应力的比值可达2.0以上，偏心荷载作用下则超过4.5，设计计算时须考虑各腹板剪应力的不均匀分布；均布面荷载作用下各腹板的剪应力可近似按均匀分布计算。根据腹板剪应力特点，提出单箱多室波形钢腹板组合箱梁的钢腹板剪应力计算应包括弯曲剪应力、扭转剪应力以及局部畸变产生的剪应力。

SHEAR STRESS IN THE WEBS OF SINGLE-BOX MULTI-CELL COMPOSITE BOX GIRDERS WITH CORRUGATED STEEL WEBS

To investigate the web shear behavior of single-box multi-cell composite box with corrugated steel webs (CGCSW), the web shear stress distribution is studied in this paper. Finite element models of single-box CGCSWs with two or three cells are established, which are verified by elastic loading experiments of scaled specimens. The shear strains of different webs are obtained under different kinds of lateral symmetric and eccentric loads, including concentrated loads, distributed line loads and distributed plane loads. The distribution features of the web shear stress and the causes are analyzed. The results show that the shear strains in different webs are obviously different under concentrated loads and distributed line loads because the acting positions are different. The ratio of the web shear stress and section average shear stress may exceed 2.0 under symmetric loads, and may exceed 4.5 under eccentric loads. Under concentrated loads and distributed line loads, uneven shear stress distribution in the webs should be considered correctly in structural analysis. Under distributed plane loads, the shear stress may be considered to be equal in all webs. According to the features of the shear stress distribution, it is proposed that the calculation of web shear stress should include flexural shear stress, torsional shear stress and shear stress caused by local section distortion.