起重机空腹桁架中,由于杆件截面比较大,如果按节点的理论中心距(图1的l及h)来计算就不太经济,应该考虑到在节点上竖杆宽度(2al_0)及弦杆宽度(2bh_0)的影响。这些宽度我们统称为“节点宽度”,在其范围内,杆件的惯性矩可以看作无穷大。在现有的资 Crane fasting truss, because the rod section is relatively large, if the theoretical center distance of nodes (l and h in Figure 1) to calculate the less economical, should take into account the vertical bar at the node (2al_0) and chord width (2bh_0) of the impact. These widths, which we collectively refer to as “node widths,” within which the moment of inertia of a member can be thought of as infinity. In the existing funding