前言线性弹性匀质材料梁的扭转理论在很多文献中已有论述。对于钢筋混凝土杆件,这些理论只能直接应用于混凝土开裂以前的状态。对于封闭的或短矮实心截面的钢筋混凝土梁在开裂后的扭转效应也有论述。但是对于如图1所示的这种钢筋混凝土开口薄壁杆件在开裂后的扭转计算还未引起人们的注意。这个问题虽有少数文献可供参考,但这 Preface The theory of torsion for beams of linear elastic homogeneous material has been discussed in many papers. For reinforced concrete members, these theories can only be applied directly to the concrete before cracking. The effect of torsion after cracking of closed or short solid reinforced concrete beams is also discussed. However, the calculation of the torsion of such a thin-walled reinforced concrete bar member after cracking as shown in FIG. 1 has not drawn much attention. Although there are a few literature on this issue for reference, but this