Spherical-tip indentation of viscoelastic material
Spherical-tip indentation of viscoelastic material
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DOI：
10.1016/j.mechmat.2004.03.002
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发表时间：
2005-01-01
影响因子：
3.9
通讯作者：
Gerberich, WW
中科院分区：
文献类型：
--
作者：
Cheng, L;Xia, X;Gerberich, WW
本文分析了球头压头对粘弹性固体的压痕。粘弹性固体用标准的固体模型，即三元模型来描述。基于泛函方程的方法，导出了粘弹性材料半空间的解析解。这些解决方案可以应用于可压缩和不可压缩涂层层对球尖压痕的响应。结果包括方便的近似松弛试验和蠕变试验的封闭形式公式。它们为利用纳米压痕或微压痕试验探测基材上聚合物涂层的力学性能奠定了基础。通过在硅片上进行散装聚苯乙烯（PS）涂层和干燥半结晶聚乙烯醇（PVOH）涂层的对比试验，验证了分析溶液在粘弹性聚合物上的应用。所得模量与文献值吻合较好。虽然PVOH涂层在10%相对湿度下的弹性卸载和粘弹性模型之间的结果吻合良好，但在70%相对湿度下长期保持后，粘弹性模型给出的数值要低得多。这部分归因于应变率效应。(C) 2004 Elsevier Ltd.版权所有。
In this paper, the indentation of viscoelastic solids by a spherical-tip indenter is analyzed. The viscoelastic solids are described by a standard solid model, that is, a three-element model. The analytical solutions are derived for a half-space of the viscoelastic material based on the method of functional equations. These solutions can apply to the response of compressible as well as incompressible coated layers to a spherical-tip indentation. The results include convenient closed-form formulas for approximating both relaxation testing and creep testing. They establish a fundamental basis for probing mechanical properties of polymeric coatings on substrates with nanoindentation or microindentation tests. Comparisons are made on the tests of both bulk polystyrene (PS) and drying semicrystalline polyvinyl alcohol (PVOH) coatings on a silicon wafer to verify the application of analytical solutions to viscoelastic polymers. The moduli obtained for bulk PS correspond with literature values well. While the results from PVOH coatings show good agreement between elastic unloading and viscoelastic models in 10% relative humidity, the viscoelastic model gives a considerably lower value after long-term holds in 70% relative humidity. This is partially attributed to a strain rate effect. (C) 2004 Elsevier Ltd. All rights reserved.