短纤维增强橡胶材料隔层的强度与失效分析

Strength and invalidation analysis of elastomeric barrier reinforced by short-staple fiber

对短切芳纶纤维EPDM材料试件进行了拉伸试验,利用数字图像分析法处理得到了准确的材料应力应变数据。根据火箭发动机柔性隔层的结构特点,用ABAQUS有限元分析软件建立了柔性隔层的有限元模型,利用轴对称结构大大简化了计算量。通过ABAQUS对拉伸试验数据进行拟合,得到了较为准确的超弹性本构模型,并通过此模型对隔层工作情况进行模拟,得到了隔层的实际应变情况。结果表明,当前工况下柔性隔层受载未超出材料强度极限,且尚具有较高的安全裕度,现有的安全判据是不可用的。改变壳体刚度、隔层与药住间隙计算其应变结果,并综合对比之前的结果,提出了有效的降低隔层应变方法,为隔层的优化提供了依据。

An uniaxial tensile test of the EPDM material reinforced by short-staple fiber was performed.Digital-image method was used to process the test data and obtain the accurate material stress-strain curve.According to the structure characteristics of elastomeric barrier in rocket engine,the finite element model of the barrier was established by finite element analysis software ABAQUS,the calculation was greatly simplified by using the axisymmetric structure.By fitting the tensile test data with ABAQUS,an accurate model of the hyperlasticity was obtained.The model was used to simulate the working situation of the barrier and the actual strain of interlayer was obtained.The result shows that under the working situation,the loading on the barrier does not exceed the strength limit of the material,and still has a high degree of safety,hence the current safety criterion is unavailable.The strain of barrier was calculated while changing the stiffness and the gap between barrier and grain.Comparing with the results before,the methods is put forward to reduce the barrier strain,and a method which can reduce the barrier strain effectively was put forward,which provide the basis for the optimization of the barrier.