本文提供一种计算空腹桁架的新方法——四铰节间法。分析步骤是从空腹桁架中取出一个节间,分析作用在节间上的有哪些力,计算出由外力产生的弦杆端弯矩(称做主弯矩)及由逐次校正得到的,因节间之间连续性产生的弦杆端弯矩(称做次弯矩)当校正进行到所期望的精度后,将主、次弯矩代数相加,得到弦杆端弯矩的实际值,而不是采用以往习用的改正腹杆刚度的方法。 This article provides a new method for calculating open trusses - four-joint joint method. The analysis step is to take a joint from the open truss, analyze the forces acting on the joint, calculate the bending moment of the chord end (called the main bending moment) generated by the external force, and the correction is made by successive corrections. The chord end bending moment (referred to as the secondary bending moment) produced by the continuity is calculated by adding the primary and secondary bending moments algebraically to obtain the actual value of the bending moment at the end of the chord. The previously used methods for correcting the rigidity of the web are used.