摘要
基于材料的S—N曲线 ,对材料在交变应力作用下受损、承载能力下降的过程进行讨论 ,给出计算受损材料持久极限的公式。公式型式简洁 ,可以方便地作出受损材料的S—N曲线 ,并进行疲劳强度计算。
Materials suffered from varying amplitude cycle loads are damaged along with the process of loading. With the purpose of appraising the stress life behavior of damaged materials, a series of analysis and discussion based on the S-N curve of material are carried out, and a new formula to calculate the surplus strength of damaged materials is derived. Based on the recurrent method, the new formula can be used to show the decline process of the strength of materials and obtain S-N curve of damaged materials at any stage. Further analysis shows an important factor that cycle loads lower than the material's fatigue limit can also damage materials when they act at the later period of materials life, and should not always be ignored in fatigue design. New formula is compared with the Miner formula and shows that when the levels of all cycle loads are higher than the fatigue limit of the material, the new formula gives the same results to those from the Miner formula, but when the level of cycle loads lower than the material's fatigue limit, new formula is much superior: treating these kinds of loads, Miner formula can do nothing. New formula can be looked as an extension of the Miner formula. An example in fatigue design is provided and shows that the new formula is convenient to use and the result is reasonable.
出处
《机械强度》
CAS
CSCD
北大核心
2003年第1期95-97,共3页
Journal of Mechanical Strength
关键词
持久极限
损伤
疲劳
寿命
Fatigue limit
Life
Damage
Fatigue
