基于ELM的超声多特征融合螺栓应力测量方法  

Ultrasonic multi-feature fusion bolt stress measurement method based on ELM

作　　者：陈平[1] 商秋仙 余鑫 尹爱军[1] Chen Ping;Shang Qiuxian;Yu Xin;Yin Aijun(College of Mechanical and Vehicle Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学机械与运载工程学院,重庆400044

出　　处：《仪器仪表学报》2024年第4期46-56,共11页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(52275518)项目资助。

摘　　要：针对传统超声波螺栓应力测量中存在的非线性和不适定性问题,提出一种基于极限学习机(ELM)的超声多特征融合螺栓应力测量方法。首先基于声弹性理论和散射理论,根据超声回波信号提取声时差及瑞利散射范围内多晶体材料中纵波的衰减系数等超声波特征参数。然后通过向量降维选择声时差、衰减系数和有效受力长度作为模型输入特征向量,建立了基于ELM的超声多特征融合螺栓应力测量模型。搭建螺栓轴向应力超声波测量实验平台,对不同材料和规格的螺栓进行螺栓应力的测量,并对比了使用传统的超声测量方法的测量结果,验证了传统超声检测方法的局限性。对比了ELM与其他机器学习方法包括BP、支持向量回归(SVR)的测量结果和精度。结果表明,提出的方法有效克服了传统超声测量方法的不足,能实现不同材料不同规格的螺栓应力测量,并且测量精度更高(平均相对误差为3.86%),泛化能力更好。This paper proposes an ultrasonic multi-feature fusion bolt stress measurement method based on extreme learning machine(ELM)to address the non-linearity and ill-posedness issues in traditional ultrasonic bolt stress measurement.Firstly,based on the theory of acoustic elasticity and scattering theory,ultrasonic feature parameters such as the acoustic time difference of ultrasonic waves and the attenuation coefficient of longitudinal waves in polycrystalline materials within the Rayleigh scattering range are extracted from ultrasonic echo signals.Then,by vector dimension reduction,the acoustic time difference,attenuation coefficient and effective load length are selected as the input feature vector to establish an ELM-based ultrasonic multi-feature fusion bolt stress measurement model.A bolt axial stress ultrasonic measurement experimental platform is set up to measure the stresses of bolts of different materials and specifications.The results are compared with those of traditional ultrasonic measurement methods to verify the limitations of traditional ultrasonic detection methods.The measurement results and precision of ELM are compared with other machine learning methods,including back propagation(BP)and support vector regression(SVR).The results show that the method proposed in this paper effectively overcomes the shortcomings of traditional ultrasonic measurement methods,which can measure the stress of bolts of different materials and specifications,and has higher measurement accuracy(with an average relative error of 3.86%)and better generalization ability.

关 键 词：螺栓应力 超声波测量 向量降维 ELM 多特征融合 

分 类 号：TH73[机械工程—仪器科学与技术]