针对椭圆封头存在大面积分层缺陷，计算无应力集中时的封头可靠性，同时根据压力储罐介质和加载特点，采用声发射技术对分层缺陷进行了局部监测。监测过程中采用基于护卫传感器声发射技术减少试验加载过程中介质波动对检测结果的影响。声发射监测结果表明，分层缺陷在交变载荷的作用下，存在缺陷扩展的趋势。

Armed at the large areas lamination defect in the ellipsoidal heads, its reliability is analyzed without stress concentration. According to the feature of pressure vessel working medium and loading method, the area monitoring of lamination defect is done by acoustic emission testing technique. In order to reduce the useless signal caused by the change loading during the experiment, the guard sensors technology is adopted. The results indicate that there exists the probability of the lamination defect can spread under the alternating load.