一种考虑砰击载荷的双体船湿甲板疲劳强度的计算方法

提出一种实用的计算和分析方法来考虑砰击载荷对双体船湿甲板处结构疲劳强度的影响,保证疲劳寿命预报的精度。首先,根据线性理论计算船体与波浪之间的相对运动和相对速度,并计算船体结构在波浪载荷作用下的应力响应;然后,计算湿甲板在砰击载荷作用下的非线性响应,再将线性响应与非线性响应通过方向性进行叠加,得到波浪载荷与砰击载荷联合作用的应力响应时历;最后,通过雨流计数法计算双体船在危险工况下的湿甲板疲劳损伤。研究结果可为考虑砰击载荷的双体船湿甲板疲劳强度评估提供一些参考。

A METHOD FOR FATIGUE EVALUATION OF CATAMARAN WET DECK WITH THE INFLUENCE OF SLAMMING

Slamming is a highly non-linear phenomenon between hull structure and wave. Due to the special structure of catamaran, the slamming mode is extremely different from that of traditional vessel. Besides bow emergence and enter, the slamming phenomenon of the out shell at the wet deck is also obvious. In conventional hull structure fatigue strength evaluation, the slamming load is usually not considered. However, the slamming problem is unavoidable at danger load cases, and the stress concentration of the catamaran wet deck is serious. So it is dangerous to ignore the existence of slamming in serious load cases when evaluating the structural fatigue strength. Therefore, it is necessary to study the contribution of slamming load to fatigue damage.