基于应变测量的桅杆结构拉耳焊缝损伤识别

Damage Identification of Welded Ear-plate Connection in Guyed Mast Based on Strain Measurement

基于桅杆结构拉耳表面应变对其焊缝裂纹扩展长度的敏感度分析,提出了桅杆结构拉耳焊缝损伤的两级模糊模式识别方法,并通过试验研究进行验证。采用有限元模拟建立了拉耳索力-关键点应变-焊缝裂纹扩展长度的模糊模式库;对16个不同裂纹长度的拉耳模型进行试验,以实测拉耳表面关键点应变为待识别样本,采用模糊模式识别方法对索力及焊缝裂纹扩展长度进行分步识别。结果表明:模糊数据库中的模拟数据能够反映拉耳的实际受力状态,识别焊缝裂纹扩展长度与实际裂纹长度具有较好的吻合度;对于不同索力及裂纹长度,识别焊缝裂纹扩展长度的误差在1mm之内,最大隶属度均大于0.8,识别峰值明显;该识别技术具有可行性,是实现桅杆结构损伤智能识别的一种有效手段。

Base on sensitivity analysis of surface strain of ear-plate connection in guyed mast on crack propagation length,a two level fuzzy pattern recognition method was proposed for the damage of welded ear-plate connection in guyed mast,and was verified by experimental study.The fuzzy pattern database of cable forces and key-point strains of ear-plate connections,as well as weld crack propagation lengths was developed by finite element.16 ear-plate connection models with different crack lengths were tested,and the key-point strains were measured to identify cable forces and weld crack propagation lengths by the proposed method.The results show that the simulated data in fuzzy database can reflect the actual stress state of ear-plate connection,and the identified weld crack lengths agree well with the actual weld crack lengths.For the different cable forces and crack propagation lengths,the error of identified weld crack length is within 1mm,the maximum membership degree is greater than 0.8,and the recognition peak is obvious.The recognition technology is feasible and is an effective method to realize the damage intelligent identification of guyed mast.