见面课
1. 材料力学相对理论力学能够求解超静定问题的原因是 考虑变形

1. 力法的基本思路是 将部分约束力作为外力,使其满足对应的位移条件

1. 三杆铰接结构如图,现要使杆3的轴力减小。应该采取的措施是![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/9ae9a151c3ce41c9bc5421e23e13a1dc.png) 减小杆3的横截面面积

1. 如图,竖直的刚性杆AB上铰接着三根材料相同、横截面相同、相互平行的水平等直杆。长度分别为![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/fbf38dc0f4aa40b4a95f507ac29e545b.png),![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/eca9e842c2804c94ae5b905ce83bc216.png)和![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/7a1add36e8c64d828d852c2fd294d6ae.png)。现在B端作用一个水平的集中力F。如果以![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/442b7cd8ea9c4f98b726e8ad0cb2644f.png),![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/eb7ae3a8b5d64dcab54d9af9739da914.png),![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/f448cc62e301444991b0adf8238339e9.png)和![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/ba6b86f79bb14b4f9bdc836bbb8a4541.png),![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/57669e1f02e24478afaad124de4c0592.png),![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/0ce73edfdecc48fc8b59e92771bf2d4e.png)分别表示杆1,2,3的轴力和应变值。给定以下四种情况,正确的是![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/05daf40ab0eb43e3adcb723da2efa943.png) ![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/3386e1a4177a4069b333e959a7387a41.png)

1. 如图,AB为简支梁。跨中C处与具有装配误差(空隙)的拉杆CD连接。连接后成为一次超静定结构。则变形协调条件的为![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/90c1d8fb423c44fda5543a6f7baf1644.png) ![image.png](https://image.zhihuishu.com/zhs/onlineexam/ueditor/201910/3406dc3b4a2741dfa2d1adac4735b5aa.png)

1. 对于超静定问题的超静定次数,是指 多余约束的数目;多余约束力的数目;所有未知力(力偶)与独立平衡方程个数之差

1. 运用变形比较法求超静定梁的有以下特点 求解多余未知力是关键;变形协调关系应与多余约束对应位移限制一致;相当梁不是唯一的

1. 超静定结构一般会产生温度应力和装配应力。

1. 根据平衡条件进行受力分析,是判断静定与超静定(次数)的关键。

1. 应用力法求解超静定结构的关键是根据变形协调条件以及多余力与位移的关系,建立补充方程,求解多余未知力。

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