小型快艇结构耐撞性研究

Analysis of Structural Crashworthiness for Fast Boats

船舶碰撞是一种复杂非线性瞬态响应过程,在碰撞区内的构件一般迅速进入塑性流动状态,出现撕裂、屈曲等形式的破坏和失效,因此对小型快艇结构碰撞特性进行分析非常必要。分析了艇艏撞击作用下快艇舷侧加筋结构的渐进破坏过程,给出了撞深曲线。为表征小型快艇船体结构的耐撞性能,建立了基于综合考虑塑性应变衡准和撞深衡准的小型艇结构耐撞性评价模型。最后,运用有限元法进行数值分析,开展快艇改进舷侧的结构耐撞性优化研究。数值分析表明,对于中小型快艇,碰撞损伤主要是艇体的总体弯曲变形,损伤变形区域占全船的比例较大,采用塑性应变衡准和撞深衡准能有效地刻画中小型快艇结构耐撞性。

Ship collision is a complex process consisted of non-linear instantaneous responses.After the collision occurs,the components within the collision zone will rapidly enter a plastic flowing state which entirely disables the components in formats of tearing and buckling.In this paper,the problem concerning small fast boat collisions was presented with its crashworthiness characteristics being discussed.Firstly,the progressive failure of stiffened side plates colliding with a bow was described,and the corresponding penetration depth was analyzed.Next,a crashworthiness evaluation model was established for small boat structures by considering their plastic strain criterion and the penetration depth criterion comprehensively.Finally,the numerical simulation was conducted using finite element analysis,and the optimization proce dure for crashworthiness of an innovative side structure was investigated.The results show that for small fast boats,the collision damage mainly comes from the overall deformation of the hull,whose region occu pies a large proportion of the boat.In brief,using plastic strain and penetration depth as criterion is both feasible and effective in crashworthiness evaluation tests.