弯曲疲劳对不同厚度聚合物材料力学性能的影响  

Effect of Bending Fatigue on Mechanical Properties of Polymeric Materials with Different Thickness

作　　者：王章凯[1,2] 熊玉竹[1,2] 刘振宇[1,2] 梅文杰[1,2] 

机构地区：[1]贵州大学材料与冶金学院,贵州贵阳550025 [2]国家复合改性聚合物材料工程技术研究中心,贵州贵阳550014

出　　处：《塑料工业》2013年第10期66-69,共4页China Plastics Industry

摘　　要：采用电子万能试验机测试尼龙(PA)6、聚丙烯(PP)、高密度聚乙烯(HDPE)、低密度聚乙烯(LDPE)四种材料在不同厚度的力学性能,研究厚度对材料力学性能的影响。结果表明,在2 mm时材料在平面应力和平面应变之间有一个突变关系。弯曲疲劳之后,PA6的拉伸强度增加了22.91%。通过X射线衍射(XRD)和扫描电子显微镜(SEM)分析材料的微观结构,随着厚度减小,结晶度降低,极性键和氢键的作用力是引起PA6弯曲疲劳后拉伸强度增加的主要因素。The mechanical properties of four materials nylon （PA） 6, polypropylene （PP）, high density polyethylene （HDPE）, and low density polyethylene （LDPE） with different thickness were tested by electronic universal testing machine. The effects of thickness on the mechanical properties of materials were studied. The results showed that the plane stress and plane strain had mutation relationship when the thickness of the material was 2 mm. After the bending fatigue, the tensile strength of PA6 actually increased by 22.91%. By X-ray diffraction （XRD） and scanning electron microscopy （SEM） analysis of the microstructure of materials, the results showed that as the thickness decreased, the degree of crystallinity decreased, and the polar and hydrogen bonding force was a major factor caused the increase in tensile strength after bending fatigue of PA6.

关 键 词：弯曲疲劳 厚度 平面应力 平面应变 力学性能 

分 类 号：TQ317[化学工程—高聚物工业]