图示对称桁架在反对称荷载作用下,杆1、2、3的内力为:
A: FN1=FN2=FN3=0
B: FN1=FN2=FN3≠0
C: FN1=FN3=0，FN2≠0
D: FN1=FN3≠0，FN2=0
A: FN1=FN2=FN3=0
B: FN1=FN2=FN3≠0
C: FN1=FN3=0，FN2≠0
D: FN1=FN3≠0，FN2=0
举一反三
- 图示对称桁架在反对称荷载作用下,杆1、2、3的内力为: A: FN1=FN2=FN3=0 B: FN1=FN2=FN3≠0 C: FN1=FN3=0，FN2≠0 D: FN1=FN3≠0，FN2=0
- 图示对称桁架在正对称荷载作用下，杆1、2、3、4的内力为：( )[img=363x216]17e4440a1f6e057.png[/img] A: FN1 = FN2 = 0，FN3 = FN4≠0 B: FN1 = FN2≠0，FN3 = FN4 = 0 C: FN1 = FN2≠0，FN3 = FN4≠0 D: FN1 = FN2 = FN3 = FN4 = 0
- 图示桁架中，1、2、3杆的内力为：[img=248x145]17e0adda57e67e9.jpg[/img] A: FN1 = FN2 = FN3 = 0 B: FN1 = FN2 = FN3 均不等于0 C: FN1 = FN3 =0，FN2 不等于0 D: FN2 =0，FN1 = FN3不等于0
- 图示桁架中，1、2、3、4杆的内力为：[img=306x161]17e0adda71c66b3.jpg[/img] A: FN1 = FN2 = 0，FN3 = FN4不等于0 B: FN1 = FN2不等于0，FN3 = FN4 = 0 C: FN1 = FN2不等于0，FN3 = FN4 不等于0 D: FN1 = FN2 = FN3 = FN4 = 0
- 图示对称桁架在正对称荷载作用下，杆1、2的内力为（）[img=301x250]17e44409dff0de5.png[/img] A: FN1>;0，FN2>;0 B: FN1<;0，FN2<;0 C: FN1= －FN2≠0 D: FN1=FN2=0