摘要
针对海洋平台在交变载荷作用下的低温疲劳问题，对焊接接头处的低温疲劳裂纹扩展速率（da／dN）进行了研究。试样所用材料为海洋平台用钢ASTMA131，试样焊接接头的焊接工艺与实际管节点焊接工艺相同。试样接头部位承受弯曲循环载荷，试验环境温度分别为－25℃和20℃。通过对试验数据的处理，得出了低温和室温下的两条da／dN－ΔK曲线。结果表明，两曲线有一交点ΔKp，当应力强度因子幅值ΔK＜ΔKp时，低温环境下试样的da／dN低于室温，结构物偏于安全；当ΔK＞ΔKp时，低温环境下试样的da／dN大于室温，结构物偏于危险。
In the light of the low-temperature fatigue of offshore Platforms under the action of alternating load, the extension rate (da/dN)of the low-temperature fatigue crack on welded joints is investigated. ASTM A13l steel for offshore Platform is used as the material for the test specimen. Cycling bending load is exerted on the joints of the specimen. The test is conducted at low temperature(-25℃) and room temperature(20℃) respectively. Two da/dN - Δk curves are obtained by processing of the test data, and they have a intersection point ΔKp. When the amplitude of the stress intensity factor Δk<Δkp, da/dN of the specimen at low temperature is lower than that at room temperature, the structure is safe; while Δk>Δkp, da/dN of the specimen at low temperature is higher than that at room temperature, the structure is dangerous.
出处
《石油机械》
EI
北大核心
1997年第4期18-20,共3页
China Petroleum Machinery
基金
中国海洋石油总公司资助
关键词
海上平台
焊接接头
低温疲劳
裂纹
扩展速率
offshore platform
welded joint
low temperature fatigue
crack
extension rate
