基于Maattanen模型的冰激疲劳寿命分析

基于ANSYS系统和海洋平台自激振动Maattanen模型,提出了计算冰激疲劳寿命的一种新方法,并开发了与ANSYS系统集成使用的计算程序。利用该程序可以实现对多自由度复杂平台结构的冰激动力精细分析,并能定量确定自激冰力、结构的动力响应和节点应力。运用该程序计算了实际平台的冰激振动响应和节点疲劳寿命,分析了不同冰力参数对平台自激振动响应的影响。对使用不同冰力模型计算出的平台疲劳寿命进行的对比结果表明,较高冰速下平台动力响应较小;自激振动是造成平台疲劳损伤的主要原因。计算结果与现场观测情况一致,这进一步验证了新计算方法的可靠性,为平台冰激疲劳设计提供了依据。

Ice-induced fatigue analysis of offshore structures based on Maattanen model

A new calculating method for self-excited vibration of offshore structures was proposed by using ANSYS system and Maattanen model. A calculation program integrated with ANSYS system was presented. This program can be used to precisely analyze the dynamic behaviors of the complicated structure with multiple freedoms under ice loads and determine the ice-induced fore, dynamic response of a structure and stress of nodes. The ice-induced dynamic responses and the fatigue life of a practical platform were computed. The dynamic responses of the platform under different parameters were investigated. The influence of ice parameters on self-excited vibration of platform was analyzed. The comparison of different fatigue life of platform calculated by different ice-force model indicates that the vibration amplitude of platform is relatively small at high ice velocity. The self-excited vibration of platform is the main reason resulting in fatigue damage of the platform. The calculated data are in good agreement with the results from the field observation. The new calculation method is reasonable and applicable to the fatigue life design of ice-exited platform.