normal vibration 是什么意思

	1.	Mode of normal vibrations 正常振动模式
	2.	Analysis of the acoustic propagation properties under the sea with normal vibration method 用简正波方法分析声波在海水中的传播特性
	3.	The test result also displays that sometimes the normal vibration associated with squeal firstly occurs prior to the tangential vibration . the tangential vibration does not occur until the normal vibration gets stronger 试验发现，有时发射摩擦噪声的振动首先在法向出现，当这个法向振动比较强时，相同或相近频率的切向振动才发生。
	4.	The measured tangential force , tangential inertial force and normal vibration acceleration are decomposed using a discrete wavelet transform . the relation among these three dynamics state variables is investigated 利用小波变换技术对测量的切向力、切向惯性力和法向振动加速度进行分解，对这些动力学变量之间的相互关系进行了深层次的研究。

normal vibration是什么意思