基于ANSYS的平台波流载荷下动力分析及疲劳分析

The Dynamic and Fatigue Analysis for Offshore Platform under the Wave and Current Forces by ANSYS

介绍了使用ANSYS有限元软件对平台结构进行静力分析、动力分析和疲劳分析的方法。应用ANSYS软件可以直接对波流载荷作用下的平台进行有限元分析,而且建模简单、计算精度高,可以方便地考虑载荷的随机性。根据ANSYS计算得到的应力,应用管节点的热点应力公式得到平台构件实际的疲劳应力,并使用S-N曲线法计算平台构件的疲劳损伤。对实际的平台进行数值计算,计算出的平台位移最大值和响应周期与现场实际测量值基本一致,这说明计算方法和数学模型是正确的。ANSYS有限元软件可以方便地计算平台结构在波浪、海流载荷下的动力响应和疲劳寿命,是进行平台设计和校核的有效工具。

The static, dynamic and fatigue analysis for offshore platform using the finite element method by ANSYS software is introduced in this paper. By use of ANSYS, the finite element analysis for offshore plat form under wave and current loads is convenient, and the construction of the model is simple, the precision of this method is relatively high, the randomicity of the loads is taken into account. The formulae of hotspot stress of tubular joint were used to calculate the actual fatigue stress, and the fatigue damage of the component was calculated by S-N curve. A calculating example is given, the maximal displacement and the vibration period of platform, which was calculated by use of ANSYS, were agree with the practice, and it shows that the calcu lating method and mathematical model in this paper is correct. The ANSYS software is suitable for the dynamic-analysis and fatigue analysis of offshore platform, and it is an effective tool in the platform design.