中文摘要：

气阀的撞击和气体压力的冲击均会产生声发射信号,声发射信号的频率范围宽,信息量丰富,在无损检测领域已得到了广泛应用,将声发射传感器引入柴油机排气阀的故障监测诊断中,以WP10.240N型柴油机为研究对象,搭建试验测试平台,模拟3种类型的排气阀故障,通过试验研究了柴油机气阀在不同状态下声发射信号特征,提取了与排气阀故障相关的特征参数,探索了基于声发射信号的柴油机气阀故障诊断的可行性。

英文摘要：

Acoustic emission signal occurs due to impact of valves opening and closing and impulse of cylinder pressure,which is characterized by a broad range of frequency and rich information about functioning and condition of diesel engines.Therefore,it has been used as a nondestructive examination method.In this work,three exhaust valve artificial fault experiments are conducted in a test platform of WP10.240N diesel engine in order to investigate the feasibility of monitoring the condition of exhaust valve of a diesel engine based on acoustic emission signals,the characteristics of the acoustic emission signals are extracted.It is shown that acoustic emission signals are sensitive and feasible to exhaust valve conditions.