K节点应力集中系数的试验和数值研究方法

工程中常用的评价海洋平台中管节点疲劳寿命的方法是使用S-N曲线。当管节点承受疲劳载荷作用的时候,可以通过数值或者试验方法得到沿着焊缝处的热点应力幅的大小。然后通过S-N曲线,可以预测此节点在破坏前可以承受疲劳载荷的循环次数。应力幅的大小可以由应力集中系数这个参数来确定。对K型节点在承受基本载荷作用下的应力集中系数进行了数值和试验分析,得到了各种基本载荷作用下K节点沿着焊缝处应力分布情况和极值应力点的位置。

EXPERIMENTAL AND NUMERICAL STUDIES OF THE STRESS CONCENTRATION FACTOR (SCF) OF TUBULAR K-JOINTS

The most commonly used method to estimate the service life of a tubular joint in offshore engineering is by referring to S-N curves. The hot spot stress (HSS) range along the weld toe is obtained by either numerical method or experimental test if a tubular joint is subjected to fatigue loadings. From a corresponding S-N curve, the number of fatigue loading cycles that the joint can sustain before failure can be predicted according to the HSS range. The HSS range is frequently calculated from a parameter called stress concentration factor (SCF). In this study, numerical and experimental analyses of the SCFs of tubular K-joints subjected to basic loadings were conducted. The stress distributions along the weld toe and the corresponding locations of the peak SCF values of the K-joints subjected to different basic loadings were obtained.