• 2021-04-14
    机构在图示瞬时有,若A点的虚位移为drA,则B点的虚位移的大小drB=____________________,OC杆中点D的虚位移的大小drC=_________________________。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/78a1ce1550834117b5fb6d4e762ea8d8.png