求解静力学问题的一般思路是通过列出力的平衡方程和力矩的平衡方程来求解,但对于复杂的平衡问题,由于研究对象多,要考虑的因素多,解答常会显得非常繁琐.利用虚位移原理来处理此类问题,有时会简明很多.虽然虚位移原理通常用来求系统外力,但也可以通过巧妙的处理来求出系统内力. The general idea of ​​solving static problems is to solve them by listing the equilibrium equations of force and the equilibrium equations of moments. However, for complex problems, many factors need to be considered and the solutions often appear to be very cumbersome.Using the principle of virtual displacement To deal with such problems, sometimes a lot easier.Although the principle of virtual displacement is usually used to seek the system external force, but also can be cleverly handled to find the system internal forces.