摘要
针对金属棒料在变幅载荷作用下需要较精确地获取其V形槽尖端裂纹扩展寿命的问题,通过给定一个工程上能接受的瞬断区尺寸,获得了棒料断裂频率的计算公式,在此基础上,建立了变幅载荷作用下棒料V形槽尖端裂纹扩展寿命的数学表达式。分析了每个频率持续时间和每次频率递减量对裂纹扩展寿命的影响规律。针对下料机的共振效应对裂纹扩展寿命影响的复杂性问题,提出了共振影响因子的概念。45钢和20钢棒料的下料试验结果表明,利用提出的棒料V形槽尖端裂纹扩展寿命公式所计算的下料时间和实际试验时棒料下料所用的时间基本一致。
In order to calculate the crack expansion life in the action of variable amplitude load for the metal bar with V-shaped notch, the formula of bar fracture frequency was obtained theoretically by setting a size of bar fracture region applied in the engineering. Based on it, the mathematic expression of crack expansion life of bar V--shaped notch tip in the action of variable amplitude load was built. The influences of the durative time of every step variable frequency and the value of every step frequency change on the crack expansion life were analyzed in detail. To solve the influence of the resonance effect of the cropping machine on the crack expansion life, the resonance factor was proposed herein. The cropping experimental results for 45 steel bar and 20 steel bar show that the cropping time obtained by the formula of the crack expansion life proposed is consistent with the practical one on the whole.
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2009年第12期1423-1425,共3页
China Mechanical Engineering
基金
中国石油大学(华东)博士科研基金资助项目(Y070311)
关键词
下料
裂纹
扩展寿命
变幅载荷
共振影响因子
cropping
crack
expansion life
variable amplitude load
resonance factor
