Brittle Fracture in the Context of Fatigue Testing
Wide variety of cast material applications and efforts to find optimum fields for casting operation are the reasons why it is so important to collect as many data on the properties of materials as possible. The problem of primary importance is to know how these materials will behave under the normally and rapidly changing loads, in other words-to know their fatigue strength. Therefore methods to investigate and evaluate this phenomenon are being improved all the time. There are many achievements related with new fatigue models and criteria (mAlnly within the area of HCF and LCF) , and all of them help us to predict the life of different materials and products when operating under the conditions of uniaxial and multiaxial mechanical loads, applied at ambient or high temperatures. This study gives a short characteristic of fatigue tests and compares various data collected during measurements of the Low-cycle fatigue strength coefficient K with the values of constant K,c, representing fracture toughness. Additionally, the Low-cycle fatigue research enabled preliminary validation of both LCF and MLCF. The results of the investigations described here have revealed some important correlations that exist between the total elongation As and the proposed brittleness criterion B, conventional stress K, and fracture toughness K,c Very important from the cognitive point of view is also a correlational relationship between the proposed brittleness criterion B and fracture toughness c An important aspect of the proposed brittleness criterion is that it enables collecting data on the properties of a relatively large material volume, while the results of fracture toughness measurements refer only to a small volume of the tested material, usually surrounding the notch area. Considering the fact that the results of a comparative analysis of the LCF and MLCF tests give hope for a wide - spread application of the latter technique in fatigue testing of materials, its development to include the brittleness measurements seems to be of great importance and opens the field for further studies on practical implementation of this method.
fatigue resistance Low-cycle fatigue test (LCF) brittle fracture material constants
Maria MAJ
Chair of Foundry Process Engineering, Section of Machines and Casting Design, Faculty of Foundry Engineering, AGH University of Science and Technology, Cracow, Poland
国际会议
69th World Foundry Congress(第69届世界铸造会议 WFC 2010)
杭州
英文
1039-1044
2010-10-16（万方平台首次上网日期，不代表论文的发表时间）