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为研究桥梁缆索镀锌钢丝的腐蚀程度、缺口形状对钢丝疲劳性能的影响规律,对3种腐蚀程度的镀锌钢丝进行疲劳试验,并根据腐蚀试件设计人造圆形、三角形和含切口的三角形缺口试件,采用试验和有限元法研究缺口试件的疲劳强度。结果表明:钢丝腐蚀越严重,腐蚀坑区域越集中,腐蚀坑越深,且疲劳强度随腐蚀程度加深而降低;在400MPa应力幅的循环作用下,圆形缺口试件到100万次仍没破坏;三角形缺口试件的疲劳强度低于圆形的,寿命很短;带切口的三角形缺口试件寿命更短,且与切口长度无关;三角形缺口试件的S～N曲线与实际腐蚀钢丝的S～N曲线有相似的趋势;缺口应力集中系数实测和有限元计算值表明缺口形状是疲劳强度降低的主要因素。
In order to study the corrosion degree of galvanized steel wire and the influence of notch shape on the fatigue property of steel wire, three kinds of galvanized steel wire with corrosion degree were tested for fatigue test. According to the corrosion test piece, artificial circular, triangular and incised triangle Notched specimens, the fatigue strength of notched specimens was studied by means of experiment and finite element method. The results show that the corrosion of the steel wire is more serious, the corrosion pits are more concentrated, the corrosion pits are deeper, and the fatigue strength decreases with the corrosion degree. Under the cyclic stress of 400MPa, The fatigue strength of the triangular notched specimens is lower than that of the circular ones and the service life is very short. The triangular notched specimens with notches have shorter life span and no relationship with the length of the notches. The S ~ N curve of the triangular notched specimens and the actual S ~ N curves have a similar trend; measured stress concentration factor and finite element calculated values show that the notch shape is the main factor to reduce the fatigue strength.