設(shè)備材料表面粗糙度的分形表征及其對(duì)界面粘附強(qiáng)度的影響
發(fā)布時(shí)間：2018-08-19 17:47
【摘要】：設(shè)備開車前或中間檢修過程都需要對(duì)設(shè)備進(jìn)行清洗,確保設(shè)備安全、高效運(yùn)行。設(shè)備材料的表面特性對(duì)污垢顆粒界面粘附力的影響較大,表面粗糙程度是其中尤為關(guān)鍵的要素。定量、準(zhǔn)確的描述設(shè)備材料的表面粗糙程度,并建立其與污垢顆粒界面粘附性能之間的關(guān)系將有助于深入了解污垢顆粒與設(shè)備材料粗糙表面的相互作用,為設(shè)備表面除污提供基礎(chǔ)理論。由于材料的粗糙表面具有自相似性,故分形理論可以實(shí)現(xiàn)表面形貌的有效表征。而分形參數(shù)的精確求解依賴于無標(biāo)度區(qū)間的準(zhǔn)確識(shí)別,為此,本文基于密度峰聚類算法首先提出一種識(shí)別無標(biāo)度區(qū)的新方法。通過銑削、刨削和研磨工藝對(duì)新方法加以驗(yàn)證,方法適用性強(qiáng)、精確度高,對(duì)大數(shù)據(jù)量高密度的數(shù)據(jù)運(yùn)行時(shí)間短,辨識(shí)效果較好。傳統(tǒng)指標(biāo)在理論上具有尺度相關(guān)性的特征,而分形指標(biāo)理論上具有尺度無關(guān)的特性。然而在實(shí)際粗糙表面表征中,二者的尺度獨(dú)立性是否與理論相一致有待實(shí)驗(yàn)驗(yàn)證。本文以銑削加工、刨削加工和研磨加工的粗糙表面為研究對(duì)象,考察兩種指標(biāo)的尺度獨(dú)立性,結(jié)果發(fā)現(xiàn)傳統(tǒng)指標(biāo)在任何條件下均不具有尺度獨(dú)立性,與理論相符;分形指標(biāo)在多數(shù)條件下也不具有尺度獨(dú)立性,與理論有出入。進(jìn)一步研究分形指標(biāo)尺度獨(dú)立性的過程中發(fā)現(xiàn),分形指標(biāo)隨尺度的變化分為不穩(wěn)定分形區(qū)和穩(wěn)定分形區(qū)。本文在對(duì)二維表面輪廓線的過程中,將臨界點(diǎn)的求取轉(zhuǎn)化為取樣長度和夾角α值的定量關(guān)系求解,通過實(shí)驗(yàn)得出其定量關(guān)系,用于確定穩(wěn)定分形區(qū)。采用原子力顯微鏡測(cè)顆粒在不同粗糙表面的粘附力,結(jié)合固體污垢清除機(jī)理分析,發(fā)現(xiàn)表面的粗糙程度對(duì)界面粘附力的影響較大。研究表明Ra0.4627μm時(shí),隨著表面粗糙度增加,粘附力減小;1.3461μmRa2.9755μm時(shí),粘附力逐漸增大;Ra3μm時(shí),粘附力保持穩(wěn)定。粘附力隨著分形指標(biāo)的變化而變化,其變化趨勢(shì)與傳統(tǒng)指標(biāo)正好相反。隨著分形維數(shù)的增大,粘附力先是保持穩(wěn)定,后逐漸增大,隨著加工工藝的改變,表面粗糙程度有個(gè)劇烈的變化,分維值銳減,后逐漸增大。
[Abstract]:The equipment must be cleaned before or during maintenance to ensure the safe and efficient operation of the equipment. The surface characteristic of the equipment material has a great influence on the adhesion force of the dirt particle interface, and the surface roughness is the most important factor. The quantitative and accurate description of the surface roughness of the equipment material and the establishment of its relationship with the adhesion property of the dirt particle interface will help to understand the interaction between the dirt particle and the rough surface of the equipment material. Provides the basic theory for the equipment surface decontamination. Because the rough surface of the material has self-similarity, fractal theory can effectively characterize the surface morphology. The exact solution of fractal parameters depends on the accurate identification of scale-free interval. Therefore, based on the density peak clustering algorithm, a new method to identify scale-free region is proposed in this paper. The new method is verified by milling, planing and grinding technology. The method has strong applicability, high accuracy, short running time for data with high data density and good identification effect. The traditional index has the characteristic of scale correlation in theory, while the fractal index has the characteristic of scale independent in theory. However, in the actual rough surface characterization, whether the scale independence of the two is consistent with the theory needs to be verified by experiments. Taking the rough surface of milling, planing and grinding as the research object, this paper investigates the scale independence of the two indexes. The results show that the traditional indexes do not have the scale independence under any condition, which is consistent with the theory. The fractal index does not have scale independence under most conditions, which is different from the theory. It is found that the fractal index can be divided into unstable fractal region and stable fractal region with the change of scale. In this paper, in the process of 2-D surface contours, the critical point is transformed into a quantitative relationship between the sampling length and the angle 偽, and the quantitative relationship is obtained through experiments, which is used to determine the stable fractal region. The adhesion force of particles on different rough surfaces was measured by atomic force microscope (AFM). Combined with the analysis of solid dirt removal mechanism, it was found that the roughness of the surface had a great influence on the adhesion force of the interface. The results show that when the surface roughness increases with the increase of Ra0.4627 渭 m, when the adhesion force decreases by 1.3461 渭 mRa2.9755 渭 m, the adhesion force increases gradually with Ra3 渭 m, and the adhesion force remains stable. The adhesion force changes with the change of fractal index, and the change trend is opposite to that of traditional index. With the increase of fractal dimension, the adhesion force keeps stable at first, then increases gradually. With the change of processing technology, the roughness of the surface changes dramatically, the fractal dimension decreases sharply, and then increases gradually.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ050.4
[Abstract]:The equipment must be cleaned before or during maintenance to ensure the safe and efficient operation of the equipment. The surface characteristic of the equipment material has a great influence on the adhesion force of the dirt particle interface, and the surface roughness is the most important factor. The quantitative and accurate description of the surface roughness of the equipment material and the establishment of its relationship with the adhesion property of the dirt particle interface will help to understand the interaction between the dirt particle and the rough surface of the equipment material. Provides the basic theory for the equipment surface decontamination. Because the rough surface of the material has self-similarity, fractal theory can effectively characterize the surface morphology. The exact solution of fractal parameters depends on the accurate identification of scale-free interval. Therefore, based on the density peak clustering algorithm, a new method to identify scale-free region is proposed in this paper. The new method is verified by milling, planing and grinding technology. The method has strong applicability, high accuracy, short running time for data with high data density and good identification effect. The traditional index has the characteristic of scale correlation in theory, while the fractal index has the characteristic of scale independent in theory. However, in the actual rough surface characterization, whether the scale independence of the two is consistent with the theory needs to be verified by experiments. Taking the rough surface of milling, planing and grinding as the research object, this paper investigates the scale independence of the two indexes. The results show that the traditional indexes do not have the scale independence under any condition, which is consistent with the theory. The fractal index does not have scale independence under most conditions, which is different from the theory. It is found that the fractal index can be divided into unstable fractal region and stable fractal region with the change of scale. In this paper, in the process of 2-D surface contours, the critical point is transformed into a quantitative relationship between the sampling length and the angle 偽, and the quantitative relationship is obtained through experiments, which is used to determine the stable fractal region. The adhesion force of particles on different rough surfaces was measured by atomic force microscope (AFM). Combined with the analysis of solid dirt removal mechanism, it was found that the roughness of the surface had a great influence on the adhesion force of the interface. The results show that when the surface roughness increases with the increase of Ra0.4627 渭 m, when the adhesion force decreases by 1.3461 渭 mRa2.9755 渭 m, the adhesion force increases gradually with Ra3 渭 m, and the adhesion force remains stable. The adhesion force changes with the change of fractal index, and the change trend is opposite to that of traditional index. With the increase of fractal dimension, the adhesion force keeps stable at first, then increases gradually. With the change of processing technology, the roughness of the surface changes dramatically, the fractal dimension decreases sharply, and then increases gradually.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ050.4
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 張懷亮;鄒佰文;肖雷;;一種辨識(shí)磨粒群分形無標(biāo)度區(qū)的新算法[J];中國機(jī)械工程;2014年03期
2 王文健;汪洪;郭俊;劉啟躍;朱e，
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