机构地区: 上海交通大学
出 处: 《中国造船》 2000年第3期40-46,共7页
摘 要: 利用三维绕射理论计算平台主体波浪力 ,对张力腿平台的总体响应进行了分析研究。在此基础上 ,系索被模拟成一空间有限元结构 ,在系索的顶端施加平台的运动以及系索张力 ,对系索进行了极限响应分析和系索疲劳可靠性分析。在极限响应分析中 ,对系索分别进行了静力和动力分析。动力分析在频域内进行 ,得到了系索应力的传递函数 ,并对其进行长期预报得到极限工况下的系索应力。系索疲劳可靠性分析建立在系索频域响应的基础上。假设波浪载荷的长期分布是由 k个短期海况组成 ,且每一海况中的应力范围的短期分布服从 Rayleigh分布。利用系索的应力传递函数得到每个短期海况的应力谱。然后 ,采用 Miner线性累积损伤模型 ,对系索结构进行了疲劳可靠性分析 ,并考虑了平均应力的影响以及进行了雨流修正。 The present paper presents a comprehensive response analysis for TLP tendons. First, the overall analysis of TLP response is carried out, in which the wave force is calculated using diffraction theory. The motions of the hull and the tension at the top of the tendon are subsequently used as input for the study of a tendon, modeled as space frame finite elements. The study of the tendon comprises the extreme response and fatigue response analyses. In the extreme response analysis, the static analysis and the dynamic analysis in the frequency domain are performed. Then the extreme stress responses of the tendon are computed based on the transfer functions of the stress found from the dynamic analysis. In the fatigue analysis, the long-term stochastic load process is divided into k short-term cases which are in Rayleigh distribution. The stress spectra of the short-term cases are determined on the basis of the transfer functions of the tendons. Finally the Miner model and the Wirsching method are applied to calculate the fatigue reliability of the tendon. In the calculation, the mean stress and the rainflow correction are taken into account.
领 域: [天文地球]