异种材料摩擦焊件的多物理信息融合临界失效监测新方法

A New Method of Critical Failure Monitoring for the Heterogeneity Material Friction Welding Specimens Applying Multiple Physical Signals

摘要:

疲劳断裂是异种材料摩擦焊零件常见的失效形式。为减少摩擦焊零件突然断裂造成的重大事故,本文从疲劳能量耗散和微观缺陷演化等角度,探讨了联合应用微红外、声发射和微电阻无损检测技术同步动态监测摩擦焊试件临界疲劳损伤的可行性。研究发现疲劳试验过程中,三种信号可同步采集,互不干扰,互相印证。进入临界断裂阶段后,对于试件的异常和正常疲劳断裂,微电阻与声发射的幅值和能量参数变化规律存在良好的映射关系,它们均可作为预警临界断裂失效的参数。虽然红外热像技术常被用于通过监测试样温度场的变化预测材料疲劳极限,但指数增长式的温度快速上升阶段在临界断裂前未必出现。与单信号监测相比,多物理信息融合健康监测预警的可信度更高,有利于提高摩擦焊零件的服役安全性和可靠性。

Abstract:

Fatigue fracture is a common failure mode for dissimilar materials friction welding components. To reduce the major accidents caused by sudden fracture of friction welding parts, the paper discussed the feasibility of the combined usage of electric resistance (ER), infrared thermograph (IRT) and acoustic emission (AE) to monitor the critical fatigue damage from the perspectives of energy dissipation and micro defects evolution. The study found that three kinds of signal could be acquired synchronously. They are non-interfering and mutual support. After entering the critical fracture stage, there is a good mapping relationship between ER and the AE ampjavascript:EditorCenter();litude and energy for the specimens of abnormal and normal fracture. They all can be regarded as the parameters of monitoring critical failure. Although IRT is usually used to predict the fatigue limit of materials, but the rapid temperature rising stage may not always be obvious near the fracture. Compared with the single signal monitoring, multi- information fusion has the higher credibility, which is beneficial to increase the service safety and reliability of friction welding parts.