基于Gerber模型的DFR腐蚀折算系数及其试验测定  

Theoretical and Experimental Determination of DFR-corrosion-influence-factors Based on Gerber Model

作　　者：陈跃良 吴省均 卞贵学 张勇 王安东 黄海亮 张柱柱 CHEN Yueliang;WU Xingjun;BIAN Guixue;ZHANG Yong;WANG Andong;HUANG Hailiang;ZHANG Zhuzhu(Naval Aeronautical University Qingdao Branch,Qingdao 266041)

机构地区：[1]海军航空大学青岛校区

出　　处：《材料导报》2019年第16期2793-2798,共6页Materials Reports

基　　金：国家自然科学基金(51375490)~~

摘　　要：为了将细节疲劳额定值(DFR)法的适用范围扩展到腐蚀条件下,采用腐蚀折算系数对DFR进行当量折算的方法,建立了基于Gerber模型的DFR法在腐蚀条件下的分析方法,并通过腐蚀折算系数的分解使此法可用于单独研究地面预腐蚀和空中腐蚀疲劳对DFR的影响。通过设置九组不同时长(0 h、6 h、12 h、24 h、36 h、72 h、108 h、144 h和180 h)的预腐蚀疲劳试验,测定了2024-T3铝合金的地面停放腐蚀折算系数;比较了基于Gerber模型和Goodman模型的DFR法在一般条件和腐蚀条件下的计算结果。结果表明:随着预腐蚀时间的延长,2024-T3铝合金的细节疲劳额定值截止值(DFR cutoff)下降;在九组不同时长下,基于Gerber模型计算的DFR cutoff依次为84.251 MPa、84.722 MPa、79.683 MPa、80.745 MPa、77.026 MPa、74.996 MPa、75.613 MPa、76.186 MPa和73.798 MPa,地面停放腐蚀折算系数为1、1.006、0.946、0.958、0.914、0.890、0.897、0.904、0.876,拟合得到DFR cutoff与预腐蚀时长满足:DFR cutoff=84.521[lg(t+10)]-0.149 8。在未考虑腐蚀影响的条件下N 95/95>10 5时,考虑腐蚀影响的条件下N 1>10 5时,基于Gerber模型计算的DFR均大于基于Goodman模型的计算结果。In order to extend the applicability of the new DFR method to corrosion conditions,via transfer the influence of corrosion environment on fatigue life to the DFR equivalently,the DFR method based on Gerber model under corrosive environment for fatigue analysis was established,and the decomposition of DFR-corrosion-influence-factors enables this method to study the effect of ground-corrosion-influence and air-corrosion-fatigue-influence on DFR independently.The ground-corrosion-influence-factor of 2024-T3 aluminum alloy was determined by nine different pre-corrosion fatigue tests.Under normal conditions and corrosion conditions,the calculation results of the DFR method based on Goodman model and Gerber model were compared.Results show that as the pre-corrosion time increases,the DFR cutoff of 2024-T3 aluminum alloy decreases;the DFR cutoff based on Gerber model are 84.251 MPa,84.722 MPa,79.683 MPa,80.745 MPa,77.026 MPa,74.996 MPa,75.613 MPa,76.186 MPa and 73.798 MPa respectively,and the ground-corrosion-influence-factor is 1,1.006,0.946,0.958,0.914,0.890,0.897,0.904,0.876 the fitting curve of the DFR cutoff with the pre-corrosion time is DFR cutoff=84.521[lg(t+10)]-0.149 8.Calculating found under the condition of neglecting the influence of corrosions when N 95/95>10 5 cycle,under the condition of considering the influence of corrosions when N 1>10 5 cycle,the calculation results of DFR method based on Gerber model is greater than that of DFR method based on Goodman model.

关 键 词：预腐蚀疲劳试验 细节疲劳额定值(DFR) 腐蚀折算系数 

分 类 号：V252.2[一般工业技术—材料科学与工程]