不同振动特性参数对振动沉管/压实的影响

Effect of different characteristic parameters of vibrationon vibration tube sinking/compaction

摘要:

振动钻探或沉管/压实机械在工程中有着广泛的应用，但缺乏频率比、阻尼比对振动沉管机械功率影响的系统研究，施工中有时会出现功率异常增大，其驱动功率如何计算仍然困扰着工程设计人员。本文通过阻尼耗散功率法，来分析计算惯性和非惯性激励振动机械的平均功率、瞬时功率问题。结果显示，大阻尼（0.5＜ ζ ＜1）全频率范围的一般情况，惯性激励系统耗散功率近似与激振力角频率平方成正比，仅在小阻尼（阻尼比 ζ ＜0.5）共振区，功率与激振力幅值的平方成正比，与阻尼成反比，正是小阻尼易引起功率异常增大；非惯性激励机械在有阻尼共振区附近工作才能吸收足够的功率。振动沉管机械设计时不仅要满足系统的平均功率的需求，还要校验最大瞬时功率需求。

Abstract:

Vibration drilling or tube sinking/compacting machinery is widely used in construction works but the systematic analysis of the influence of the frequency ratio on vibration tube sinking machinery power is also lacking. Furthermore, the driving power sometimes increases abnormally, and how to calculate it still perplexes engineering designers. In this paper, the average power and instantaneous power of inertial and non inertial excited vibration machinery is calculated and analyzed with the damping dissipation power method. The results show that, the dissipation power of the inertia excited vibration system is approximately proportional to the square of the excitation force angular frequency in the whole frequency range for large damping (0.5＜ ζ ＜1). For small damping (damping ratio ζ ＜0.5), only in the resonance range the power is proportional to the square of the excitation force amplitude and inversely proportional to damping. Moreover, it is the small damping that causes abnormal power increase. Non inertial excitation machinery can only absorb enough power when working near the damped resonance range. During the design of vibration tube sinking machinery, not only is it necessary to meet the average power requirement of the system, but also to verify the maximum instantaneous power requirement.