periodical variation

• 周期性变化

periodical variation的用法和样例：

例句

1. Variations in the properties of the weld occurring at short regular intervals along the weld line due to repetitive variation in welding heat.
   由于焊接热量周期变化，使得沿焊缝线每一固定的小间距焊缝的性能出现周期性变化。
2. Parametric rolling is a kind of the resonance phenomena of ship motions, caused by the periodical fluctuations of stability parameters of ships in waves.
   参数横摇是指船舶在波浪中由于自身系统中稳性参数的周期性变化所引起的船体梁横摇共振运动现象。