题目2单选题
如图刚性梁AB,在A点铰接,B和C处由两杆约束,若D点的力F力引起B点的铅垂位移为20mm,则杆1的应变和D点位移分别为( ).<img src="https://tihai-oss-cloud.itihey.com/img/13865ee04d9bcd7557526d09bc5f1c6f.png">A. <img src="https://tihai-oss-cloud.itihey.com/img/8374d8030e73603dbadcd4cc73749d10.png">和1.43mmB. <img src="https://tihai-oss-cloud.itihey.com/img/84cec91d51d0f76a2025fe7f0fcf6452.png">和14.3mmC. <img src="https://tihai-oss-cloud.itihey.com/img/1f4d7378d7122f5650ea4d0a358375ec.png">和14.3mmD. <img src="https://tihai-oss-cloud.itihey.com/img/1dfe34fe04b1f4cd296fa8973798d60e.png">和1.43mm