裂纹形态对丁腈橡胶力学性能和耐疲劳性能的影响

The Effect of Kinds and Diameter of Flaws on Crack Development of NBR Rubber

丁腈橡胶为石化行业应用最为广泛的一类橡胶材料。在受到周期应力的作用下,丁腈橡胶内已存在的裂纹会不断扩展而最终导致橡胶断裂。本文考察了预制缺陷的种类及大小对丁腈橡胶疲劳过程中裂纹扩展情况的影响,并对断面形貌进行了观察。结果表明,在圆形、纵向和横向三种缺陷中,纵向缺陷对丁腈橡胶的力学性能和耐疲劳性能影响最小;对圆形缺陷来讲,随孔直径的增大,丁腈橡胶的耐疲劳性能和力学性能逐渐下降。

NBR products are widely used in petrochemical industry. Under conduction of cyclic stress,the cracks in rubber will continue to develop until rubber breaks. In this paper, the effect of kinds and diameter of flaws on crack development of NBR rubber was investigated and the fraction surfaces were observed using SEM. The results show that parallel cracks have the littlest effect on mechanical properties and fatigue property of NBR rubber in parallel, cross and round crack and that both mechanical properties and fatigue property of NBR rubber become poorer with increase of diameter of round flaws.