期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
Fatigue Life Evaluation Method for Foundry Crane Metal Structure Considering Load Dynamic Response and Crack Closure Effect 被引量:1
1
作者 Qing Dong Bin He Gening Xu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第2期525-553,共29页
To compensate for the shortcomings of quasi-static law in anti-fatigue analysis of foundry crane metal structures,the fatigue life evaluation method of foundry crane metal structure considering load dynamic response a... To compensate for the shortcomings of quasi-static law in anti-fatigue analysis of foundry crane metal structures,the fatigue life evaluation method of foundry crane metal structure considering load dynamic response and crack closure effect is proposed.In line with the theory of mechanical vibration,a dynamic model of crane structure during the working cycle is constructed,and dynamic coefficients under diverse actions are analysed.Calculation models of the internal force dynamic change process of dangerous cross-sections and a simulation model of first principal stress-time history are established by using the steel structure design criteria,which is utilised to extract the change of first principal stress of danger points over time.Then,the double-parameter stress spectrum is obtained by the rain flow counting method.The fatigue life calculation formula is corrected by introducing a crack closure parameter that can be calculated by the stress ratio and the effective stress ratio.Under the finite element model imported into Msc.Patran,crack propagation analysis is performed by the growth method in the fatigue integration module Msc.Fatigue.Taking the metal structure of a 100/40t-28.5m foundry crane with track offset as an example,the accuracy of calculation results and the feasibility and applicability of the proposed method are verified by theoretical calculation and finite element simulation,which provide a theoretical basis for improvement of the fatigue resistance design of foundry cranes. 展开更多
关键词 Metal structure of foundry crane load dynamic effect crack closure effect crack propagation fatigue life.
下载PDF
DETERMINATION OF CLOSURE EFFECT IN FATIGUE CRACKING BY MEANS OF COMPLIANCE TECHNIQUE AND NUMERICAL METHOD
2
《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1992年第1期38-42,共5页
The crack tip strain gauge method in the compliance technique was used to determine the opening load of notched crack of axle steel,and the nonlinear finite element ADINA program, to which the cyclic stress-strain cur... The crack tip strain gauge method in the compliance technique was used to determine the opening load of notched crack of axle steel,and the nonlinear finite element ADINA program, to which the cyclic stress-strain curve of axle steel was applied,was used to analyze the stress-strain field ahead of the crack tip and the opening load of notched crack.The results of both the compliance technique and the numerical method were in good agreement.In this pa- per,the concept of the sensitive point is proposed and the key to the determination of the crack opening load in the experiment is to place a strain gauge at sensitive point.It is certified by both experimental and numerical methods that the sensitive point has the best linear relation- ship character and the value of strain is much greater. 展开更多
关键词 crack closure effect compliance technique numerical method axle steel
下载PDF
THRESHOLD OF SHORT FATIGUE CRACK FOR Al-Li ALLOY 8090
3
作者 CHEN Zheng Northwestern Polytechnical University,Xi′an,China Lab.No.401,Northwestern Polytechnical University,Xi′an 710072 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1991年第2期135-138,共4页
Threshold of fatigue for short through cracks for Al-Li alloy 8090 was evaluated to be lower than that of long cracks,and to decrease with the shortening of the crack length.The correla- tion among the threshold,crack... Threshold of fatigue for short through cracks for Al-Li alloy 8090 was evaluated to be lower than that of long cracks,and to decrease with the shortening of the crack length.The correla- tion among the threshold,crack wake,and crack tip shielding of the short fatigue cracks was discussed.The super demarcation length and lowest theoretical threshold of short through fa- tigue cracks were presented. 展开更多
关键词 Al-Li alloy short fatigue crack THRESHOLD crack closure effect crack tip shielding
下载PDF
A general model of fatigue crack growth under variable amplitude loading 被引量:6
4
作者 LIU JianTao DU PingAn ZHANG ZhenYu 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第3期673-683,共11页
A general model of fatigue crack growth(FCG) in ductile alloys under variable amplitude loading is proposed based on the passivation-lancet theory and the crack closure concept.The model can capture the interactions o... A general model of fatigue crack growth(FCG) in ductile alloys under variable amplitude loading is proposed based on the passivation-lancet theory and the crack closure concept.The model can capture the interactions of single cycle overloading and underloading,sequential loading and spectrum loading effectively.Moreover,the retardation effect due to overloads and the acceleration effect due to underloading can be described quantitatively by a transition function of crack opening stress.The fatigue test data in 2024-T351,2024-T3 and 7075-T6 aluminum alloys under different types of variable amplitude loading and spectrum loading are used to validate the general model and the predictions by the general model are in good agreement with the test data.Furthermore,the predictions are also compared with the existing models,including FASTRAN,AFGROW and the state-space model,and the comparison results show that the general model predicts the FCG process more accurately. 展开更多
关键词 fatigue and fracture crack retardation effect variable loading crack closure effect plastic effect
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部