已知图示结构<img src="https://static.zxtiku.com/wangke/imgs/topic/660dc0b62d4db4496a9d92d76335dd69.png"/>常数，当<img src="https://static.zxtiku.com/wangke/imgs/topic/2ae46b5e3cfbb97afe0bf222ec8d711c.png"/>点水平位移为零时，<img src="https://static.zxtiku.com/wangke/imgs/topic/e2396f4612b7f44ecb25b219673d43fe.png"/>应为：<br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/1506a38a0a018d33c74141cfaf92c3a1.png"/