作业名称：试写出用力法计算图示结构的典型方程
作业要求：（采用右图所示基本体系），并求出方程中的全部系数和自由项（不求解方程）。已知各杆EI=常数。
土工试验是获取土物理力学参数的一项基本工作，我们必须掌握每一个试验参数获取的整个试验步骤以及计算过程，但对于大量的物理力学参数，并不都是通过试验得到，我们只需进行一部分试验得到部分参数后，其他物理力学参数便可通过已知参数与待求参数之间换算公式便可求得，这就要求我们必须掌握他们之间的换算关系。
《工程力学》命题作业
如图所示的平面桁架，在铰链H处作用了一个20kN的水平力，在铰链D处作用了一个60kN的垂直力。求A、E处的约束力和FH杆的内力。
计算二重积分
Studying Abroad
In recent years, studying abroad has been popular in our country. More and more middle school students would like to go abroad through mediators.
Is it good or bad to study abroad?
In my opinion, on one hand, it has some advantages. Studying abroad can provide better studying conditions. People can make rapid progress in their foreign language study and it can also help widen their field of vision. Meanwhile, young students can learn advanced science and technology from foreign countries and spread cultures of different nations. Besides, studying abroad can also improve the ability of students’ self-dependence
On the other hand, it has disadvantages. For example, because of the lack of living experience and poor capability to take care of themselves, they may feel lonely and homesick. In addition, high living expenses and tuition fees will become a heavy burden upon their parents.
So I think whether studying abroad or not should be decided according to oneself and one's family. It is not right to follow others. By the way, with the development of our society, China is getting more and more stronger. It also has a good studying condition. We can learn the same thing in our own country and spend little money. With the development of the national economy, Chinese people are getting richer and richer that their style of living and the way of