基于振动频率法的船舶系缆力试验研究

Experimental study of ship mooring force based on vibration frequency method

现有的系缆力测量方法尚无法实现简单、准确、高效地测量单根船舶缆绳的系缆力。参考测量斜拉索索力的计算方法,进行了振动频率法测量船舶系缆力的试验研究。依据实际系泊环境搭建了原型测试平台,并针对可能产生理论误差的影响因素与实际应用要求,进行不同数据采集位置、激励方式、激励位置、浸湿缆绳和不同温度等影响因素的误差试验研究,提出基于环境激励和人工激励的新激励方式。通过分析振动频率法的计算值与原型测试平台的张拉值,得出数据采集位置、激励位置和激励方式对船舶系缆力测量值影响很小,缆绳浸湿下误差率范围增大1.5%左右,低温下(2℃)误差率增加±2%左右,综合误差范围为-5%~4%且误差率可以较好地满足正态分布,通过修正缆绳长度对测量精度进行修正。结果表明该方法具有较强的可行性与应用性,能有效实现简单、准确、高效地测量船舶系缆力。

The current method for measuring mooring force is unable to accurately and efficiently measure the force of a single ship cable.This paper presents an experimental study on measuring ship mooring force using the vibration frequency method,with reference to the calculation method of cable force measurement of cable-stayed cables.A prototype testing platform was built based on the current mooring environment.The study investigated the error rates of different data acquisition locations,excitation modes,excitation positions,and wet cables,taking into account the influencing factors that may cause theoretical errors and practical application requirements.The study proposed a new excitation mode based on environmental and manual excitation.Through an analysis of the vibration frequency method and tension values on the prototype test platform,it is concluded that the measured value of the ship mooring force is minimally impacted by the data acquisition position,excitation position,and excitation method.The error rate increases by approximately 1%in the presence of wet cables,resulting in a comprehensive error range of-5%to 4%.This error rate satisfies the normal distribution,and the measurement accuracy is corrected by correcting the length of the cable.It has been demonstrated that this method is highly feasible and applicable,and can effectively achieve simple,accurate,and efficient measurement of ship mooring force.