【摘要】：作為柔性鉸鏈機(jī)構(gòu)的核心單元,柔性鉸鏈的選型與參數(shù)設(shè)計(jì)直接關(guān)系到機(jī)構(gòu)的整體性能。由于對(duì)各種切口型式的柔性鉸鏈的研究是獨(dú)立完成的,每種鉸鏈都對(duì)應(yīng)一套十分復(fù)雜的設(shè)計(jì)計(jì)算公式,這使得柔性鉸鏈機(jī)構(gòu)的設(shè)計(jì)者在選擇鉸鏈型式時(shí)難度很大。在進(jìn)行柔性鉸鏈參數(shù)設(shè)計(jì)之前,設(shè)計(jì)者主要根據(jù)經(jīng)驗(yàn)來(lái)完成柔性鉸鏈的選型,這樣難以保證所選擇的鉸鏈切口型式最佳。柔性鉸鏈的通用模型方法,通過(guò)通用的解析模型將多種切口形狀的柔性鉸鏈統(tǒng)一起來(lái),從而將柔性鉸鏈切口型式的選擇和參數(shù)設(shè)計(jì)兩個(gè)過(guò)程合二為一。論文基于圓錐曲線類(lèi)柔性鉸鏈的通用模型,以橋式柔性位移放大機(jī)構(gòu)為研究對(duì)象,研究柔性位移放大機(jī)構(gòu)的運(yùn)動(dòng)靜力學(xué)和動(dòng)力學(xué)建模、應(yīng)力分析以及涉及柔性鉸鏈切口選型和機(jī)構(gòu)幾何參數(shù)(包括柔性鉸鏈的幾何參數(shù))的多目標(biāo)優(yōu)化設(shè)計(jì)。論文完成的主要工作有:(1)利用圓錐曲線的統(tǒng)一極坐標(biāo)方程,提出了一種圓錐曲線類(lèi)柔性鉸鏈的通用模型,并基于小變形梁假設(shè),推導(dǎo)了柔性鉸鏈沿各個(gè)方向柔度的解析表達(dá)式;基于圓錐曲線類(lèi)柔性鉸鏈的通用模型,綜合考慮機(jī)構(gòu)中柔性鉸鏈的切口形狀及幾何參數(shù)、機(jī)構(gòu)中剛性桿的幾何參數(shù),建立了柔性位移放大機(jī)構(gòu)的靜力學(xué)分析模型;基于該模型分析了柔性鉸鏈切口形狀及機(jī)構(gòu)幾何參數(shù)對(duì)機(jī)構(gòu)靜力學(xué)性能的影響,以及柔性鉸鏈幾何參數(shù)加工誤差對(duì)機(jī)構(gòu)靜力學(xué)性能的影響。(2)基于力插值的有限元法,采用單位載荷法推導(dǎo)了柔性鉸鏈的通用位移插值函數(shù),并利用位移插值函數(shù)給出了圓錐曲線類(lèi)柔性鉸鏈的一致質(zhì)量矩陣表達(dá)式�；趫A錐曲線類(lèi)柔性鉸鏈的通用模型,建立了單個(gè)柔性鉸鏈的動(dòng)力學(xué)方程,并分析了柔性鉸鏈切口形狀及幾何參數(shù)對(duì)其基頻的影響。(3)分別基于偽剛體模型和多柔體系統(tǒng)動(dòng)力學(xué)理論,建立了柔性位移放大機(jī)構(gòu)的動(dòng)力學(xué)分析模型;基于圓錐曲線類(lèi)柔性鉸鏈的通用模型,分析了機(jī)構(gòu)中柔性鉸鏈的切口形狀及機(jī)構(gòu)幾何參數(shù)對(duì)放大機(jī)構(gòu)最低階固有頻率的影響。(4)基于圓錐曲線類(lèi)柔性鉸鏈的通用模型,研究了平面載荷作用下柔性鉸鏈中的應(yīng)力分布,并根據(jù)畸變能密度屈服準(zhǔn)則,給出了柔性鉸鏈最大名義應(yīng)力的計(jì)算公式及強(qiáng)度校核條件;基于有限元仿真分析數(shù)據(jù),采用數(shù)值擬合法,得到了圓錐曲線類(lèi)柔性鉸鏈的拉伸應(yīng)力集中系數(shù)和彎曲應(yīng)力集中系數(shù)的經(jīng)驗(yàn)計(jì)算公式,并考慮應(yīng)力集中影響給出了平面載荷作用下柔性鉸鏈及位移放大機(jī)構(gòu)最大應(yīng)力的計(jì)算公式。(5)根據(jù)使用性能原則,在保證機(jī)構(gòu)固有頻率的前提下,以柔性鉸鏈的失效抗力指標(biāo)為材料選擇原則,基于Ashby圖法分析了柔性鉸鏈的材料選擇,給出了幾種適合加工柔性鉸鏈機(jī)構(gòu)的材料。(6)在綜合考慮靜力學(xué)、動(dòng)力學(xué)性能及應(yīng)力條件下,給出了位移放大機(jī)構(gòu)的綜合評(píng)價(jià)函數(shù),并進(jìn)行了位移放大機(jī)構(gòu)的參數(shù)優(yōu)化設(shè)計(jì)。根據(jù)優(yōu)化結(jié)果加工樣機(jī),并搭建樣機(jī)實(shí)驗(yàn)平臺(tái),通過(guò)實(shí)驗(yàn)測(cè)試了位移放大機(jī)構(gòu)樣機(jī)的位移放大比,有限元仿真結(jié)果和實(shí)驗(yàn)結(jié)果驗(yàn)證了理論模型的正確性。
[Abstract]:As the core unit of the flexible hinge mechanism, the selection and parameter design of the flexible hinge are directly related to the overall performance of the mechanism. Since the study of flexible hinges for various cut-outs is done independently, each hinge corresponds to a complex set of design formulas, which makes the designer of the flexible hinge mechanism difficult to select in the choice of the hinge type. Prior to the design of the flexible hinge parameters, the designer is primarily based on experience to select the flexible hinge, which makes it difficult to ensure that the selected hinge cut type is optimal. The universal model of the flexible hinge is used to unify the flexible hinges of various cut-out shapes through a universal analytical model, so that the choice of the flexible hinge cut-out type and the parameter design are combined into one. Based on the general model of the flexible hinge of the cone curve, the paper studies the static and dynamic modeling of the flexible displacement amplifying mechanism by using the bridge type flexible displacement amplification mechanism as the research object. The stress analysis and the multi-objective optimization design involving the selection of the flexible hinge cut and the geometric parameters of the mechanism, including the geometric parameters of the flexible hinge. The main work of the thesis is as follows: (1) Using the uniform polar coordinate equation of the conic curve, a general model of the flexible hinge with a conic curve is proposed, and the analytical expression of the flexibility of the flexible hinge in various directions is derived based on the hypothesis of the small deformation beam. Based on the general model of the flexible hinge of the conical curve, the geometrical parameters of the flexible hinge in the mechanism and the geometric parameters of the rigid rod in the mechanism are taken into consideration, and the static analysis model of the flexible displacement amplifying mechanism is established. Based on this model, the influence of the shape of the flexible hinge notch and the geometric parameters of the mechanism on the static performance of the mechanism is analyzed, and the influence of the processing error of the flexible hinge on the static performance of the mechanism is analyzed. (2) Based on the finite element method of force interpolation, the general displacement interpolation function of the flexible hinge is derived by the unit load method, and the uniform quality matrix expression of the flexible hinge of the conic curve is given by using the displacement interpolation function. The dynamic equation of a single flexible hinge is established based on the general model of the flexible hinge of the conic curve, and the influence of the shape and the geometric parameters of the flexible hinge on the fundamental frequency is also analyzed. (3) the dynamic analysis model of the flexible displacement amplification mechanism is established based on the pseudo-rigid body model and the multi-soft body system dynamics theory, The influence of the notch shape of the flexible hinge and the geometric parameters of the mechanism on the lowest order natural frequency of the amplifying mechanism is analyzed. (4) The stress distribution in the flexible hinge under the action of plane load is studied based on the general model of the flexible hinge of the conic curve, and the calculation formula and the strength check condition of the maximum nominal stress of the flexible hinge are given according to the distortion energy density yield criterion. based on the finite element simulation analysis data, the empirical formula of the tensile stress concentration coefficient and the bending stress concentration coefficient of the conical curve type flexible hinge is obtained by adopting the numerical simulation method, The calculation formula of the maximum stress of the flexible hinge and the displacement amplifying mechanism under the action of a plane load is given in consideration of the influence of the stress concentration. (5) According to the principle of service performance, on the premise of ensuring the natural frequency of the mechanism, the material selection principle of the flexible hinge is analyzed based on the failure resistance index of the flexible hinge, and the material selection of the flexible hinge is analyzed based on the Ashby method, and a plurality of materials suitable for processing the flexible hinge mechanism are provided. (6) Under the conditions of static, dynamic and stress, the comprehensive evaluation function of the displacement amplification mechanism is given, and the parameter optimization design of the displacement amplification mechanism is carried out. According to the optimization result, the prototype is processed, and the experimental platform of the prototype is set up. The displacement amplification ratio, the finite element simulation result and the experimental results of the displacement amplification mechanism prototype are tested by the experiment. The correctness of the theoretical model is verified.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TH112

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳蘊(yùn)博;岳麗杰;;機(jī)械工程材料優(yōu)選方法的研究現(xiàn)狀[J];機(jī)械工程學(xué)報(bào);2007年01期

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本文編號(hào)：2423310