计算简图如图1(a),P为单位集中移动荷载。切断EF杆以X_1作为基本未知力,基本体系如.图1(b)。由力法方程可得经实例计算梁中的切力及各杆件的轴变向形对基本未知力X_1的影响很小仅为千分之几,故可忽略不计,于是以上二个积分可用图乘法来计算(计算公式可由手册中查得),计算时沿梁分为三段,并设 The calculation diagram is shown in Figure 1(a). P is the unitized moving load. Cut off the EF rod with X_1 as the basic unknown force, the basic system is shown in Fig. 1(b). From the force law equation, it can be calculated that the shear force in the beam and the axial deflection of each member are only a few thousandths of the impact of the basic unknown force X_1, so the above two points can be used. Graph multiplication (calculation formula can be found in the manual), calculation is divided into three sections along the beam, and set