本文選題：柔性鉸鏈　切入點(diǎn)：精密定位機(jī)構(gòu)　出處：《華南理工大學(xué)》2016年博士論文　論文類(lèi)型：學(xué)位論文

【摘要】：柔順精密定位平臺(tái)在精密加工、半導(dǎo)體制造業(yè)和生物醫(yī)學(xué)工程等領(lǐng)域得到廣泛應(yīng)用,構(gòu)成平臺(tái)主體的柔順機(jī)構(gòu)在重復(fù)運(yùn)動(dòng)過(guò)程中承受交變應(yīng)力而易發(fā)生疲勞失效。傳統(tǒng)平臺(tái)往往基于靜力強(qiáng)度和確定性方法設(shè)計(jì),這可能導(dǎo)致機(jī)構(gòu)提前疲勞失效或過(guò)量設(shè)計(jì)。本文主要對(duì)平面柔順精密定位機(jī)構(gòu)的疲勞可靠性進(jìn)行研究,在此基礎(chǔ)上優(yōu)化設(shè)計(jì)了滿(mǎn)足要求疲勞壽命和可靠性的機(jī)構(gòu)。此外,建立了鉸鏈的疲勞損傷剛度退化模型,并以此為基礎(chǔ)研究了平面柔順機(jī)構(gòu)疲勞損傷特性分析方法,全文研究?jī)?nèi)容如下:(1)為了建立平面柔順精密定位機(jī)構(gòu)精確的分析模型,研究了柔順機(jī)構(gòu)建模分析的偽剛體封閉環(huán)方法和有限單元方法。推導(dǎo)了直圓型柔性鉸鏈等典型單元的剛度矩陣,以平面三自由度柔順精密定位機(jī)構(gòu)為研究對(duì)象,采用有限單元方法求解了機(jī)構(gòu)的雅克比矩陣、最大工作范圍、驅(qū)動(dòng)力、固有頻率和各個(gè)鉸鏈的最大靜應(yīng)力。分析結(jié)果與商業(yè)ANSYS軟件的仿真結(jié)果進(jìn)行對(duì)比,驗(yàn)證了本文方法的有效性。(2)綜合考慮材料、尺寸參數(shù)和表面狀況等對(duì)鉸鏈疲勞極限的影響,基于材料靜力強(qiáng)度估測(cè)了鉸鏈的疲勞極限,給出了典型鉸鏈的S-N曲線。以平面三自由度柔順精密定位機(jī)構(gòu)為研究對(duì)象,基于有限單元和序列二次規(guī)劃方法對(duì)各個(gè)鉸鏈的最大疲勞應(yīng)力及其所在位置進(jìn)行了分析。結(jié)合鉸鏈S-N曲線,預(yù)測(cè)了鉸鏈及機(jī)構(gòu)在恒幅載荷下的疲勞壽命。采用雨流計(jì)數(shù)法進(jìn)行循環(huán)計(jì)數(shù),預(yù)測(cè)了機(jī)構(gòu)在變幅載荷下的疲勞壽命。結(jié)果顯示,基于靜力強(qiáng)度理論設(shè)計(jì)的機(jī)構(gòu)有時(shí)會(huì)提前疲勞失效。為此,以機(jī)構(gòu)疲勞強(qiáng)度、最大驅(qū)動(dòng)力及最低固有頻率為約束條件,以機(jī)構(gòu)的工作范圍最大為目標(biāo)函數(shù),給出了一種新的基于疲勞強(qiáng)度理論的平面柔順機(jī)構(gòu)優(yōu)化設(shè)計(jì)方法,有效解決了傳統(tǒng)基于靜力強(qiáng)度理論設(shè)計(jì)的機(jī)構(gòu)會(huì)提前疲勞失效的問(wèn)題。(3)將材料和尺寸參數(shù)等處理為隨機(jī)變量,采用矩法和代數(shù)法分別計(jì)算機(jī)構(gòu)中各個(gè)鉸鏈疲勞應(yīng)力及疲勞強(qiáng)度的方差,基于應(yīng)力強(qiáng)度干涉理論,對(duì)鉸鏈及機(jī)構(gòu)的疲勞可靠性進(jìn)行建模分析,結(jié)果顯示基于靜力強(qiáng)度設(shè)計(jì)的機(jī)構(gòu),疲勞可靠性有時(shí)不能滿(mǎn)足要求。為此,以平面三自由度柔順精密定位機(jī)構(gòu)為研究對(duì)象,給出了一種基于疲勞可靠性理論平面柔順機(jī)構(gòu)優(yōu)化設(shè)計(jì)方法,并分析了機(jī)構(gòu)疲勞可靠性同各尺寸參數(shù)及方差的關(guān)系。最后通過(guò)Monte-Carlo仿真和實(shí)驗(yàn)驗(yàn)證了設(shè)計(jì)方法的有效性。(4)對(duì)直圓型柔性鉸鏈進(jìn)行疲勞試驗(yàn),提出使用三個(gè)特征點(diǎn)和多段曲線對(duì)鉸鏈剛度曲線進(jìn)行建模的方法,并擬合了鉸鏈特征壽命同疲勞應(yīng)力的關(guān)系。通過(guò)改變鉸鏈尺寸參數(shù)進(jìn)行了疲勞試驗(yàn),建立了鉸鏈的疲勞應(yīng)力集中系數(shù)同尺寸參數(shù)和特征壽命的關(guān)系。通過(guò)進(jìn)行非零平均應(yīng)力下鉸鏈的疲勞試驗(yàn),給出了其等效疲勞應(yīng)力公式。在此基礎(chǔ)上,研究了基于有限單元方法的平面柔順機(jī)構(gòu)疲勞損傷特性預(yù)測(cè)方法,以柔順橋式放大機(jī)構(gòu)為例,實(shí)驗(yàn)驗(yàn)證了方法的有效性。
[Abstract]:Compliant precision positioning platform in precision machining, widely used in semiconductor manufacturing and biomedical engineering field, compliant mechanism constituted the main part of the platform under repetitive motion in the process of alternating stress and prone to fatigue failure. The traditional platform often static strength and definite method based design, which may lead to early fatigue failure or excessive design. This paper makes the research on the fatigue reliability of planar compliant precision positioning mechanism, based on the optimization design to meet the requirements of fatigue life and reliability of the mechanism. In addition, the establishment of the fatigue damage of hinge stiffness degradation model, and based on the analysis method of fatigue damage characteristics of planar compliant mechanism, the research contents are as follows: (1) in order to establish the analysis model of planar compliant precision positioning mechanism accurately, study the pseudo rigid body sealing analysis of compliant mechanism modeling The closed loop method and finite element method. The stiffness matrix of right circular flexure hinge and other typical units are derived, with three degree of freedom planar compliant precision positioning mechanism as the research object, using the finite element method for solving the Jacobian matrix of the mechanism, the maximum working range, maximum driving force, natural frequency and static stress of each hinge. The simulation results were compared with the commercial ANSYS software results, verify the validity of this method. (2) considering the effect of material, size and surface condition of the hinge fatigue limit of material, static strength estimation of fatigue limit of hinge based on S-N curve is given. Taking the plane hinge three free precise positioning of compliant mechanism as the research object, the maximum fatigue finite element and the sequence of two quadratic programming method of each hinge based on stress and its position are analyzed. Combined with S-N curved hinge To predict the fatigue life of the hinge line, and in constant amplitude loadings. The rain flow counting method for cycle counting, prediction of fatigue life in institutions under variable amplitude loading. The results show that the static strength theory to design the mechanism based on sometimes early fatigue failure. Therefore, the mechanism of fatigue strength, maximum and minimum driving force the inherent frequency as constraints, the largest in the scope of work of the organization as the objective function, this paper presents a new optimization method based on planar compliant mechanism of fatigue strength theory, an effective solution to the traditional static strength design theory will advance the mechanism based on fatigue failure problems. (3) the material and size parameters are treated as random variables with the moment method and the algebra method. The computer is in the structure of each hinge fatigue variance force and fatigue strength, the stress strength interference theory based on fatigue reliability of hinge and mechanism Modeling and analysis results show that the static strength design of mechanism based on fatigue reliability, sometimes can not meet the requirements. Therefore, the planar three DOF compliant precision positioning mechanism as the research object, an optimization design method for fatigue reliability theory of planar compliant mechanism is proposed based on analysis of the relationship between the organization and the fatigue reliability with the dimension parameter and variance finally, the effectiveness of the design method is verified by Monte-Carlo simulation and experiments. (4) the fatigue test of straight circular flexure hinge, proposed method using three feature points and multi curve modeling of the hinge stiffness curve, and the relationship between the characteristics of life with hinge fitting fatigue stress by changing the hinge. The size parameters of the fatigue test, a hinge fatigue stress concentration factor with the size parameter and characteristic life relationship. Through the non zero mean stress The fatigue test of hinges is given, and the equivalent fatigue stress formula is given. Based on that, the prediction method of fatigue damage characteristics of planar compliant mechanism based on finite element method is studied. Taking the compliant bridge amplification mechanism as an example, the validity of the method is verified by experiments.

【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：TH112

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本文編號(hào)：1650474