Nanoindentation methods for viscoelastic characterization of stiff porous materials

Background Modifying the mechanical properties of the solid phase of a porous material, in this study calcium-silicate-hydrate, is frequently possible by changing synthesis conditions, but changes in these conditions can also influence porosity, which in turn may affect the mechanical properties of the porous material. Experimental methods to decouple porosity from the viscoelastic properties of the porous material will aid in optimization of the structure of the solid phase to achieve the desired mechanical properties. Â Objective Explore different nanoindentation techniques in order to determine the viscoelastic properties of the solid phase (without the affect of porosity) of a stiff porous material via experimental methods alone. Â Methods Compacted pellets of calcium-silicate-hydrate were prepared with different porosity and subjected to three nanoindentation techniques to determine viscoelastic behavior and the influence of porosity: dynamic, stress relaxation, and creep. Results ..., Compacted pellets of calcium-silicate-hydrate were prepared with different porosity and subjected to three nanoindentation techniques to determine viscoelastic behavior and the influence of porosity: dynamic, stress relaxation, and creep. Results of the porosity and of the viscoelastic behavior measurements were analyzed with a reverse-micromechanics model to determine viscoelastic properties of the solid phase, which has not been achieved previously for calcium-silicate-hydrate. These methods can be used in development and refinement of materials to determine how changes in the solid phase (e.g. molecular structure) influence viscoelastic behavior while considering the effect of porosity., , # Nanoindentation Methods for Viscoelastic Characterization of Stiff Porous Materials This data set contains data from three different types of nanoindentation experiments (stress relaxation, creep, and dynamic) on two different specimens (calcium-silicate-hydrate with different levels of porosity). The data are organized into folders for each experiment and specimen type. Stress relaxation: 1. \"Load and Depth\" folder contains the raw data for indents used in analysis 2. .txt file ending in \"SR_analysis.txt\" contains nanoindentation data analyzed by the nanoindenter software package 3. .txt file beginning with \"SR_fittedmean\" contains the mean normalized stress relaxation data with 95% confidence intervals. Creep: 1. \"Load and Depth\" folder contains the raw data for indents used in analysis 2. .txt file ending in \"crp_analysis.txt\" contains nanoindentation data analyzed by the nanoindenter software package 3. .txt file beginning with \"SC_E_s\" contains the mean solid elastic modulus...研究背景 本研究的对象为多孔材料的固相——钙硅水合物（calcium-silicate-hydrate）。通过调整合成条件，通常可调控多孔材料固相的力学性能，但此类条件变化往往同时会改变孔隙率，进而可能对多孔材料的整体力学性能产生影响。开发能够将孔隙率与多孔材料粘弹性特性解耦的实验方法，将有助于优化固相结构以获得预期的力学性能。 研究目标 探索多种纳米压痕（nanoindentation）技术，以期仅通过实验手段，精准测定刚性多孔材料固相（不受孔隙率干扰）的粘弹性性能。 研究方法 本研究制备了不同孔隙率的压实钙硅水合物颗粒球团，并采用三种纳米压痕技术：动态纳米压痕、应力松弛纳米压痕与蠕变纳米压痕，以表征其粘弹性行为及孔隙率的影响。通过反细观力学模型（reverse-micromechanics model）对孔隙率与粘弹性性能的测试结果进行分析，以求解固相的粘弹性参数，这在钙硅水合物体系中此前尚未实现。该方法可用于材料开发与性能优化，在考量孔隙率影响的前提下，明确固相（如分子结构）变化对粘弹性行为的调控规律。 # 刚性多孔材料粘弹性表征用纳米压痕方法 本数据集包含两类不同孔隙率的钙硅水合物试样的三种纳米压痕实验数据，分别为应力松弛、蠕变与动态纳米压痕实验。数据按实验类型与试样类型分别归档至对应文件夹中。 1. 应力松弛实验： 1. "Load and Depth"文件夹存储用于分析的压痕原始数据 2. 后缀为"SR_analysis.txt"的文本文件包含纳米压痕仪软件分析得到的纳米压痕数据 3. 前缀为"SR_fittedmean"的文本文件包含归一化应力松弛平均数据及95%置信区间。 2. 蠕变实验： 1. "Load and Depth"文件夹存储用于分析的压痕原始数据 2. 后缀为"crp_analysis.txt"的文本文件包含纳米压痕仪软件分析得到的纳米压痕数据 3. 前缀为"SC_E_s"的文本文件包含平均固相弹性模量……