Evaluation of Time Dependent Behavior of a Wood Flour/High Density Polyethylene Composite
Evaluation of Time Dependent Behavior of a Wood Flour/High Density Polyethylene Composite
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DOI：
10.1177/0731684408096427
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发表时间：
2010-01
影响因子：
3.1
通讯作者：
F. Dastoorian;M. Tajvidi;G. Ebrahimi
中科院分区：
文献类型：
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作者：
F. Dastoorian;M. Tajvidi;G. Ebrahimi
对含有 30% 高密度聚乙烯 (HDPE)、67% 杉木粉、2% 相容剂 (MAPE) 和 1% 润滑剂的木塑复合材料进行短期弯曲蠕变和应力松弛试验。在蠕变测试中，施加的应力水平为测得的弯曲强度的 30% 至 60%。采用时间—应力叠加原理，形成最长4年的主曲线。水平位移因子符合阿累尼乌斯方程。还在极限应变的 30% 至 60% 的应变水平下进行了应力松弛测试。应用时间—应变叠加原理，形成了延伸67天的应力松弛主曲线。水平位移因子也符合阿伦尼乌斯型方程。将所得主曲线与外推蠕变和应力松弛模型进行比较。为了确定时间-应力叠加对于所研究的复合材料是否有效，将蠕变位移因子应用于应力松弛数据，反之亦然。在蠕变和应力松弛试验中，发现叠加的应用得到了验证。结果表明，所研究的复合材料流变学简单，时间轴上的单个水平移动足以预测材料的长期性能。
Short-term flexural creep and stress relaxation tests were conducted on a wood plastic composite containing 30% high density polyethylene (HDPE), 67% fir wood flour, 2% compatibilizer (MAPE), and 1% lubricant. In creep tests, applied stress levels ranged from 30 to 60% of measured flexural strength. The principle of time—stress superposition was applied to form a master curve extending for a maximum of 4 years. The horizontal shift factors conformed to an Arrhenius type equation. Stress relaxation tests were also carried out at strain levels ranging from 30 to 60% of the ultimate strain. The principle of time—strain superposition was applied to form a stress relaxation master curve that extended for 67 days. The horizontal shift factors also conformed to an Arrhenius type equation. The resulting master curves were compared with extrapolated creep and stress relaxation models. To determine whether time—stress superposition is valid for the studied composite material, creep shift factors were applied to stress relaxation data and vice versa. In both creep and stress relaxation tests, it was found that the application of superposition was verified. The results indicated that the studied composite material was rheologically simple, and a single horizontal shifting on time axis was adequate to predict the long term performance of the material.