预腐蚀金属材料疲劳性能试验测试与表征模型

Test and characterization model on fatigue behavior for pre-corroded metallic aircraft materials

提出了预腐蚀金属材料疲劳性能表征S-N-t曲面模型,并建立了模型参数估计算法。采用成组法和升降法,试验测定了预腐蚀后的3种航空材料(LD2CS、LD10CS和15Cr Mn Mo VA)有擦蚀和无擦蚀疲劳S-N-t曲面,采用新建立的S-N-t曲面模型处理试验数据,发现模型曲面与试验数据吻合良好;预腐蚀材料的无擦蚀和有擦蚀疲劳性能随着预腐蚀时间的增加而下降,相同的应力水平和预腐蚀时间下,预腐蚀材料的无擦蚀疲劳性能更好。

New S-N-t surface model was proposed for characterizing fatigue behavior of pre-corroded metallic materials and novel formulae were derived to estimate the parameters of the proposed model. Fatigue lifegroup and up-down tests were conducted on un-notched and notched pre-corroded specimens for three different types of metallic aircraft materials（ LD2 CS,LD10CS and 15 Cr Mn Mo VA） to determine the fatigue S-N-t surface. Good agreements were achieved between the test and the new S-N-t surface models by applying the new proposed S-N-t surface model to the test data points. Fatigue behavior of un-notched and notched pre-corroded metallic aircraft materials decreases with the increase of pre-corrosion time. The un-notched specimens show better fatigue behavior than notched ones at the same stress level and pre-corrosion time.