摘要
填充天然橡胶材料疲劳裂纹扩模型是指裂纹扩展速率与撕裂能峰值之间的关系,它是用于橡胶减振元件疲劳寿命预测的重要模型。在裂纹扩展试验得到的填充天然橡胶材料裂纹扩展长度与循环次数的数据中,由于橡胶的应力软化现象,试验后期的部分数据不可用。为此,建立了数据处理方法,获得有效的裂纹扩展长度与循环次数数据。基于单轴拉伸载荷下填充天然橡胶材料最大应变能密度与最大应变满足幂函数关系的假设,建立了变幅加载工况下裂纹扩展长度与循环次数的数学模型和识别其模型参数的优化方法。在建立的裂纹扩展长度与循环次数模型的基础上,建立了裂纹扩展速率与撕裂能峰值关系的模型和确定模型中参数的数值方法。利用一组哑铃型试片的疲劳寿命实测数据,对建立的裂纹扩展速率模型进行了验证,证明了所建立模型的正确性。
The fatigue crack growth(FCG)model refers to the relationship between crack growth rate(defined as crack growth length versus number of cycles)and maximum tearing energy,and is used to predict the fatigue life of a rubber damping component.Usually,some of the measured relationships of crack growth length and number of cycles in a fatigue crack growth experiment cannot be used to model FCG,due to the stress softening phenomenon of filled natural rubber materials.In this study,a data processing technique is first given to obtain effective data of crack growth length versus number of cycles.Second,based on the assumption that maximum strain energy density and maximum strain have the function of the power relationship under a uniaxial tensile load,the model for modeling relations of crack growth length and number of cycles under variable amplitude loading conditions is established.Third,by using the least-squares method,the optimization method for identifying model parameters is established.On the basis of the established relations of crack growth length and number of cycles,the model for describing relationships between crack growth rate and maximum tearing energy is built,and the numerical method to obtain the constants in the mode is given.Finally,the proposed established crack growth model is validated by comparing the measured and calculated fatigue life of rubber dumbbell specimens.
出处
《振动．测试与诊断》
EI
CSCD
北大核心
2016年第1期152-159,204,共8页
Journal of Vibration,Measurement & Diagnosis
基金
国家自然科学基金资助项目(51275175)
广东省自然科学基金资助项目(2014A030313254)
关键词
裂纹扩展试验
裂纹扩展长度
循环次数
裂纹扩展速率
撕裂能峰值
模型参数识别
变幅加载工况
crack growth experiment
crack growth length
number of cycles
crack growth rate
maximum tearing energy
model parameter identification
variable amplitude loads
