疲劳损伤对NEPE推进剂力学性能的影响

The Effect of Fatigue Damage on Mechanical Property of NEPE Propellant

为了研究疲劳损伤对NEPE推进剂力学性能的影响,文中测定了NEPE推进剂不同疲劳循环周期后的弹性模量。实验采用频率为5 Hz的正弦波,循环至一定周期后卸载,再将试样进行单轴拉伸试验,并测量其初始弹性模量。基于初始弹性模量定义了损伤因子D,进而建立了疲劳损伤方程,且由实验数据拟合了方程参数。结果表明:疲劳损伤会影响NEPE推进剂弹性模量,损伤因子随循环周期增大而增大,在循环开始阶段损伤速率较快,随循环次数增加逐渐变小。

In order to study the effects of fatigue damage on mechanical property of NEPE propellant,the elastic modulus of the NEPE propellant after different fatigue cycles was determined. The fatigue tests in present work were conducted with a sinusoidal loading frequency of 5 Hz with specific cycles. After unloading,uniaxial tension tests were carried out to obtain the elastic modulus. The damage factor D was defined based on the elastic modulus,and then fatigue damage equation was established. The parameters of the equation were evaluated by fitting the fatigue test data. The results show that fatigue damage can affect the elastic modulus of the NEPE propellant. Damage factor increases with the number of cycle. At the initial stage of the cycle phases,damage evolution is fast. With the increased number of cycles, its rate of increasing reduces continuously.