中文摘要：

海上环境引起的船体外板温度昼夜交替变化及装卸载会造成薄膜型LNG船温度应力交替变化。采用综合温度折算法确定船体外板典型昼夜温度,并针对薄膜型LNG船温度场分析建立三舱段有限元模型及底边舱折角区域精细模型,采用子模型法计算出各典型温度下的结构温度应力。研究结果表明底边舱折角处温度应力与船体外板水线面上下的温度差异呈良好的线性关系,船体外板温度的日周期性变化及装卸载引起的温度交变应力对船体结构疲劳强度影响不大。

英文摘要：

The daily cyclic change of hull’s temperature caused by ocean environment as well as the effect of loading and unloading can cause alternating changes of the membrane-type LNG ship’s thermal stress.Adopting the comprehensive temperature covert method to confirm the typical daily hull temperature,the FE model of a typical membrane-type LNG ship’s three tanks is built for analyzing its thermal field,and the refined model of the hopper knuckle connection is built for accessing the thermal stress by the sub-model method.The research result shows that the thermal stress at the hopper knuckle connection has a linear relationship with the difference value between the hull’s temperature above and under the waterplane.Furthermore,the change of hull’s temperature together with the effect of loading and unloading has an insignificant influence on fatigue strength of LNG ship.