基于热点应力的罐车焊接钢结构疲劳

Study on fatigue property of welded steel structure of tanker based on hot spot stress approach

针对罐车焊接钢结构在不同服役情况下的疲劳行为进行了研究.试验过程中选取了高速路、公路、崎岖路三种典型的路况,通过所得不同部位的应变结果计算各自的热点应力,用雨流法处理后编制载荷谱,并根据线性累积损伤理论来计算各部位的疲劳寿命.结果表明,罐车焊接钢结构上不同部位在不同路况下行驶具有不同的寿命,其中最危险的部位是侧面中下处的9和10,其在高速路上行驶疲劳寿命最低,约为3.3年.结合路况和驾驶行为,实时观察波形图发现,相比于路面不平,急刹车、上下坡、转弯会对罐车焊接钢结构的寿命产生更大的影响.

The fatigue behavior of welded steel structure of tanker under different service conditions was studied. Three typical road conditions, super highway, highway and rugged road were selected. The hot spot stress was calculated by strain measurement at different positions, and the load spectrum was compiled according to the processed data by rain-flow method. Thereafter, the fatigue life of each position was calculated according to the theory of linear cumulative damage. The results showed that the different positions of welded structure had different fatigue life under different service conditions, and the dangerous positions were 9 and 10, which had the lowest fatigue life on the super highway. Combined with the road conditions and driving behavior, the real-time observation of the waveform showed that the emergency brake, climbing slope or getting down slope and turning would have a greater impact on the fatigue life compared to the road roughness.