当系统对某些激励(一般称为强迫函数)起响应时,就存在振动,图1.A和B中的重块受外力作用移动至某一位置,然后放松,重块的运动将会消失或继续下去。如果运动很快衰减,有害的连续振动将不存在,如果运动继续下去,振动也继续存在,其烈度必须进行估算,因为有许多无害的振动存在。例如飞机机翼在飞行中的摆动或汽车弹簧在路面行驶时的平稳性。 Vibration occurs when the system responds to some stimuli (commonly referred to as forced functions), and the weights in A and B are moved to a certain position by external forces and then relaxed, and the movement of the weights disappears Or continue. If the exercise decays rapidly, harmful continuous vibrations will not exist and if the exercise continues, the vibrations will continue to exist and their intensity must be estimated because there are many innocuous vibrations present. Such as the swings of the aircraft’s wings in flight or the stability of the car’s springs when driving on the road.