安全工作线是指空间双向压弯构件在受荷过程中既不发生整体弯扭屈曲,又不产生最大受力边缘纤维屈服的临界外荷载相关曲线.起重机钢结构空间压弯构件弹性稳定计算相关式依此建立. The safe working line refers to the critical load-related curve of the overall bending-torsion buckling of the space bi-directional flexural members in the process of loading, and does not produce the yield of the maximum force of the edge fibers. Based on this type of establishment.