船撞力强度指标对船撞桥响应的影响

Study on Influence of Ship Collision Force Intensity Index on Ship-Bridge Collision

确定船舶的撞击力是桥梁设计的关键问题之一,本研究针对船撞力强度指标的选择,探讨了不同船撞力强度指标对桥梁结构响应的影响.首先建立了一艘轮船撞击刚性墙的高精度有限元模型,得到了不同撞击吨位与撞击速度下的船撞力时程,并根据不同的船撞力强度指标进行了等效,将等效静力作用于结构的响应值与结构动力响应值进行了对比.结果表明,平均船撞力得出的结构响应最小,局部平均船撞力与峰值船撞力得出的动力响应相差不大;从结构响应随撞击吨位与撞击速度的变化规律方面来看,采用局部平均船撞力作为强度指标更为合理;在采用3种船撞力强度指标时都必须考虑动力效应的影响,否则会得到偏小的结构响应值.

Ship impact force determination is one of the key problems in bridge design.The paper is focused on the selection of ship collision force intensity index(SCFII),and studies the influence of different SCFII on bridge structure response.Firstly,a high-precision finite element model of ship impact rigid wall is established,and the ship collision force under different impact tonnage and impact velocity are obtained.The ship collision force is equivalent to static force according to different SCFII,and the equivalent static force is imposed on the structure,and the response is compared with the dynamic response of the structure.The results show that the structural response obtained by the average ship collision force is the smallest,and the dynamic response obtained by the local average ship collision force and the peak ship collision force is almost the same;according to the change law of the structural response with the impact tonnage and impact speed,it is more reasonable to use the local average ship collision force as the SCFII;the influence of the dynamic effect must be considered when using the three SCFIIs,and a smaller structural response will be obtained if the dynamic effect is not considered.