【摘要】 振动时效过程幅频曲线变化的理论基础是振动阻尼的变化,分析了结构阻尼(滞后阻尼)在振动时效过程中的作用,应用动态机械分析仪对焊接小试样应变阻尼进行了实测,指出了结构阻尼在振动过程中有升高后缓降的变化,这是导致幅频曲线复杂变化的原因之一。通过对比了振动时效的机械行业标准JBT5926—1991标准和JBT10375—2002标准中关于振动时效的效果的幅频曲线评定方法的异同,通过对HT-7U核聚变试验装置的振动时效幅频曲线分析,指出对焊接结构的振动时效采用JBT10375—2002技术标准进行效果评定更具实用性。更多还原

【Abstract】 The variation of vibrating damping during vibratory stress relief (VSR) is the fundamental of the vibration response changing. The structural damping (or hysteretic damping) during VSR was discussed. The amplitude-dependent internal friction (ADIF) of small laser beam welded samples were measured using dynamic mechanical analyzer.The experimental results show that the structural damping (or ADIF) first increase, then decreases slightly during VSR. This is one of the reasons that result in the variation of vibration response curves. Two methods to evaluate the effectiveness of VSR by vibration response curves were compared according to the VSR code of JB/T5926-1991 and JB/T 10375-2002. The VSR response curves of HT-7U Tokamak welded structures were analyzed. The results indicate that it is practical to adopt the Chinese VSR CODE JB/T 10375-2002 to evaluate the effectiveness of welded stresture VSR.更多还原