【作者】 贾永刚；

【导师】 冯谦；

【作者基本信息】 南京林业大学 ， 机械设计及理论， 2006， 硕士

【摘要】 关于对不同缓凝剂和防水剂对建筑石膏水化和石膏刨花板力学性能的影响国内外研究者以及本课题组其它成员已经做了比较系统的定性分析研究。揭示了不同种类的缓凝剂和防水剂对建筑石膏凝结硬化过程、二水石膏结晶形态以及石膏刨花板力学性能灰产生不同的影响。例如：柠檬酸的加入使二水石膏晶体由针状转化为短柱状，尺寸明显粗化，且柠檬酸掺量越大晶体粗化现象越严重。当柠檬酸添加量介于0.05％～0.1％之间时，石膏刨花板的内结合强度、静曲强度和弹性模量最高，随着添加量的增加其上述力学性能也逐渐变差。加入适当比例的防水剂明显地起到细化晶体，增强石膏刨花板力学性能的作用。 材料科学研究中，人们进一步注意到材料细观结构演化诱致了宏观力学行为改变。已有的细观结构定性分析的结果只反映了材料宏观力学性能的改变，而不能从材料细观结构方面定量地分析改变的一般规律，本论文寻求应用计算机图像处理技术来实现对材料细观组织的定量分析的有效方法，探讨导致材料力学性能改变的细观结构方面的定量解释。 基于数字图像处理理论和MATLAB的图像处理功能，二次开发出了应用于石膏及石膏刨花板细观结构SEM图像的处理分析方法和程序，主要包括系统构成、图像处理与分析的主要步骤、细观特征参数的提取和统计分析，以及在此基础上对晶体层的面积、孤立晶体的尺寸和晶体细长比等材料细观特征参数进行数据处理等。上述方法可适用到金属金相组织分析中，验证了方法和程序的适用性。通过实践，作者摸索并总结了石膏和石膏刨花板SEM试件制备工艺，设计了试验，为图像处理奠定了基础。 图像处理的定量分析结果进一步验证了定性分析结结论，结果证明应用上述方法和程序设计对石膏及石膏刨花板细观结构SEM图像的处理分析是可行的、有效的。探索了一条将计算机图像处理技术应用到石膏基材料和其它材料细观结构的分析中的可行路径。更多还原

【Abstract】 Effect of the kind of buffer and waterproof agent on the process of hydration of building gypsum and the mechanical properties of gypsum particleboard (GPB) were analyzed by other member of the workgroup. The results of qualitative analysis showed the kind of buffer and has the different effect on the setting and hardening of building gypsum, crystalline habit of dihydrate the physical and mechanical properties of GPB. For example, consequently leading to the transformation of dihydrate crystal from needle-like to short prismatic. Furthermore the higher the dosage of citric acid, the larger the dihydrate crystal is. The internal bond strength, the modulus of rupture and modulus of elasticity of GPB were the highest when the citric acid of 0.05%～0.1% was added. The above mechanical properties were reduced obvious as high content citric acid was added. But the dihydrate crystal is slender when the waterproof in an appropriate concentration was added, and the mechanical properties of GPB were increased.In the field of materials research, the people think that the evolvement of the materials meso-structure leads to the transformation of the mechanical properties of materials. Considering the above results of qualitative analysis can not explain why did the transformation of the mechanical properties happen from the point of view of the materials meso-structure, a method of quantitative analysis of materials meso-structure is set up using digital image processing , which will quantificationally explain what is the cause of the transformation of the mechanical properties.Based on powerful image Function of MATLB and digital image processing theory, the program and methods using to process and analyze the SEM images of gypsum board and GPB were developed, the system configure, some main methods of image processing and analysis, measuring characteristic parameters of microstructure and analyzing error are described in detail., and moreover, the feature parameters for the materials meso-structure were measured and analyzed, such as the grain distribution, the grain size and the tangent rectangle size of the gypsum grain. The application of metallographical analysis to the above program and methods, proved which were adaptive. At the same time, on the base of the practice, the general procedures of preparing of specimens of gypsum-based materials for SEM images analysis was also described in this article.Compared the results of qualitative analysis and of quantitative analysis, the result show that the program and methods using to process and analyze the SEM images of gypsum board and GPB is feasible and exact. So the analysis methods of materials meso-structure based on computer image processing is of practicability.更多还原