装甲车辆扭杆裂纹的声发射检测
李爱民，张耀辉
(北京市丰台区杜家坎21号院技术保障工程系，北京 100072)
摘 要：采用常规的无损检测手段检测装甲车辆悬挂系统扭杆裂纹损伤比较困难。为了方便地检测扭力轴上的裂纹缺陷，提出了利用声发射技术在扭杆加栽状态下，检测裂纹损伤的方法。为此基于虚拟仪器的原理，采用便携式工控机、高速数据采集卡、高灵敏传感器、手动液压加裁装置构建了扭杆检测硬件系统，并编制了专用的检测定位软件。通过实际应用试验，成功地检测到了被测装备扭杆上的损伤。通过对比分析可得，基于声发射技术的动态检测方法是解决扭杆裂纹静态检测的有效办法。
关键词：声发射检测；扭杆；裂纹；监测
中图分类号：TJ810。6；TG115.28 文献标识码：A 文章编号：1000-6656(2007)09-0529-03
Detecting of Torsion Bar Crack of the Armored Vehicle Based
on Acoustic Emission Technique
Li Ai-min,ZHANG Yao-hui
(Department of Technical Support Engineering，21 Dujiakan,Fengtai District,Beijing 100072．China)
Abstract：It is very difficult to detect the crack of torsion bar of armored vehicles suspension system by ordinary nondestructive testing method．In order to detect the crack damage of torsion bar expediently．the method for crack detecting by AE technique under loading condition was given．Based on the principle of virtual instrument,a detecting hardware system was built。 using the devices. such as portable industrial control computer,data acquisition card，high sensitive sensors and manual hydraulic loading device．Also,appropriate detecting and locating software system were programmed．The studying process and the nondestructive detecting system built for this study were summarized and analyzed．The crack of torsion bar tested was detected successfully in the experiment on real equipment．And the following result can be found out：the dynamic detecting method based on AE technique is an effectual method to solve the problem that is difficult to detect crack damage of torsion bar under static condition．
Keywords：Acoustic emission testing；Torsion bar；Crack；Monitoring
装甲车辆悬挂系统的作用基于扭杆的扭转变形特性，而装甲车辆在越野行驶过程中的动态载荷的变化非常大，扭杆将反复承受很大的交变应力，在扭杆的某一位置因疲劳易产生非常小的微观裂纹(即疲劳源)。疲劳源的产生和扩展是在工作过程中，在静态时使用常规方法无法对尺寸过小的裂纹进行检测。为了实时监测扭杆裂纹的发展变化，准确预测断裂损伤的发生时机，笔者采用声发射技术动态监测扭杆裂纹的产生及扩展情况。
1声发射技术的特点
扭杆在内部或外部产生微观裂纹或发生裂纹扩展时，会在疲劳源释放应力，从而产生弹性应力波的传递，即声发射现象。声发射技术有如下特点：
(1)整体性 无需对各缺陷位置进行逐一检测，而是通过布置在构件(或整体结构)外部若干AE传感器对所覆盖区域内任一位置的缺陷信号进行检测，便于在无法准确知道裂纹损伤位置时实施监测。
(2)动态实时性无需拆卸分解零部件即可检测，AE技术能实时监测到裂纹及故障现象并能监测到裂纹产生、扩展及断裂的动态过程。
(3)精度高AE技术理论上讲不存在最小缺陷的限制，严格来讲在裂纹产生的塑性屈服阶段都可以检测到。
