本文關(guān)鍵詞： 夾緊力 力的存在性 力的可行性 閾值 離散化 迭代　出處：《南昌航空大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：研究機(jī)械加工過程中夾緊力的合理規(guī)劃是保證加工質(zhì)量的核心環(huán)節(jié),對(duì)于實(shí)現(xiàn)加工過程中夾緊力的可靠性和工件的精密化至關(guān)重要,為此構(gòu)建了全區(qū)域夾緊力變向迭代規(guī)劃算法。根據(jù)工件在裝夾布局中的受力狀態(tài)以及工件與裝夾元件之間接觸力的方向約束條件,分別依據(jù)夾緊力大小與夾緊點(diǎn)位置的未知和已知情況,結(jié)合線性規(guī)劃技術(shù)分別建立了有靜摩擦力和無靜摩擦力的力的存在性和力的可行性分析方法。在夾緊力存在的條件下,通過離散夾緊表面為點(diǎn)集的方法,逐點(diǎn)地以一定步長(zhǎng)正向從最小值開始選取夾緊力的大小,根據(jù)當(dāng)前值與上一次取值之間可行性的差異,確定下一次取值的步長(zhǎng)及其方向,若可行性相同則以相同步長(zhǎng)繼續(xù)正向取值,否則步長(zhǎng)減少、反向取值,直至步長(zhǎng)的絕對(duì)值小于閾值,建立全區(qū)域夾緊力的變向迭代規(guī)劃算法,該算法將連續(xù)型的夾緊力設(shè)計(jì)問題轉(zhuǎn)化為離散型,并將連續(xù)的待裝夾表面轉(zhuǎn)化為點(diǎn)集,不僅適合于形狀復(fù)雜的工件,而且還利于計(jì)算機(jī)實(shí)現(xiàn)夾緊力的自動(dòng)化設(shè)計(jì)。對(duì)于當(dāng)單一夾緊力不能使工件在加工過程中穩(wěn)定,需要多點(diǎn)裝夾的情況。提出了多夾緊力迭代規(guī)劃算法。通過用合力和投影角度表達(dá)每個(gè)夾緊力。并以判斷該合力下是否至少存在一組夾緊力組合使工件穩(wěn)定為迭代標(biāo)準(zhǔn)。若此次迭代標(biāo)準(zhǔn)與上次相同時(shí),則迭代步長(zhǎng)和迭代方向不變。若不同則迭代步長(zhǎng)縮小并反向迭代。直至步長(zhǎng)的絕對(duì)值在給定的閾值范圍內(nèi)。針對(duì)迭代規(guī)劃算法的參數(shù)選取問題,本文以最少的計(jì)算次數(shù)為目標(biāo)函數(shù),運(yùn)用遺傳算法將迭代規(guī)劃算法中的三個(gè)參數(shù)進(jìn)行優(yōu)化。旨在提高算法的效率。基于復(fù)雜零件夾緊表面的夾緊力全區(qū)域規(guī)劃不僅適用于具有復(fù)雜表面的工件,而且能夠避免工件處于非穩(wěn)定狀態(tài)下優(yōu)化模型的求解過程。提高了計(jì)算效率,使夾緊點(diǎn)與夾緊力的選取有了一個(gè)計(jì)算標(biāo)準(zhǔn),為復(fù)雜工件裝夾布局方案的合理設(shè)計(jì)提供了基礎(chǔ)理論。多夾緊力迭代規(guī)劃算法則能搜尋出多個(gè)夾緊力共同作用下每個(gè)夾緊力的取值范圍,為需要多點(diǎn)裝夾的工件的夾緊力選取提供力選取標(biāo)準(zhǔn)。
[Abstract]:To study the reasonable planning of clamping force in machining process is the core link to guarantee the quality of machining, and it is very important to realize the reliability of clamping force and the precision of workpiece in the process of machining. For this purpose, an iterative programming algorithm for the whole area clamping force is constructed. According to the stress state of the workpiece in the clamping layout and the direction constraint condition of the contact force between the workpiece and the clamping element. According to the magnitude of clamping force and clamping point position unknown and known. Combining with linear programming, the existence and feasibility analysis method of static friction force and non-static friction force are established respectively. Under the condition of the existence of clamping force, the discrete clamping surface is used as the point set method. According to the feasibility difference between the current value and the last value, the step size and direction of the next value are determined according to the feasibility of selecting the clamping force from the minimum to a certain step. If the feasibility is the same, the same step size will continue to take forward value, otherwise the step size will be reduced, the reverse value, until the absolute value of step size is less than the threshold, the variable direction iterative programming algorithm of the whole region clamping force will be established. The algorithm transforms the continuous clamping force design problem into the discrete one, and transforms the continuous clamping surface into the point set, which is not only suitable for the complex workpiece. It is also helpful for the computer to realize the automatic design of clamping force. When the single clamping force is not able to make the workpiece stable in the process of processing. An iterative programming algorithm for multiple clamping forces is proposed. Each clamping force is expressed by the resultant force and projection angle, and it is determined whether there is at least one set of clamping forces under the combined force to make the workpiece stable. If this iteration standard is the same as the last time. Then the step size and the direction of iteration are unchanged. If not, the step size of the iteration is reduced and the iteration is reversed. The absolute value of the step size is within a given threshold. The parameter selection problem of the iterative programming algorithm is addressed. This paper takes the least number of calculations as the objective function. Genetic algorithm is used to optimize the three parameters of the iterative programming algorithm. In order to improve the efficiency of the algorithm, the whole area planning of clamping force based on the clamping surface of complex parts is not only suitable for the workpiece with complex surface. Moreover, it can avoid the process of solving the optimization model in unstable state, improve the calculation efficiency, and make the selection of clamping point and clamping force have a calculation standard. The iterative programming algorithm of multiple clamping forces can find out the value range of each clamping force under the combined action of multiple clamping forces. The selection standard of clamping force is provided for multi-point clamping workpiece.
【學(xué)位授予單位】：南昌航空大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TG75

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 秦國(guó)華;王華敏;葉海潮;吳竹溪;;基于力的存在性與可行性的夾緊力變向增量遞減規(guī)劃算法[J];機(jī)械工程學(xué)報(bào);2016年11期

2 秦國(guó)華;王子琨;吳竹溪;魯宇明;;基于表面網(wǎng)格離散化與遺傳算法的復(fù)雜工件裝夾布局規(guī)劃方法[J];機(jī)械工程學(xué)報(bào);2016年13期

3 秦國(guó)華;趙旭亮;吳竹溪;;基于神經(jīng)網(wǎng)絡(luò)與遺傳算法的薄壁件多重裝夾布局優(yōu)化[J];機(jī)械工程學(xué)報(bào);2015年01期

4 秦國(guó)華;葉海潮;崔躍;魯宇明;;面向計(jì)算機(jī)輔助夾具設(shè)計(jì)的修訂式定位方案設(shè)計(jì)算法[J];計(jì)算機(jī)集成制造系統(tǒng);2012年10期

5 秦國(guó)華;郭西園;葉海潮;魯宇明;;復(fù)雜工件夾緊力作用區(qū)域的規(guī)劃算法[J];兵工學(xué)報(bào);2012年07期

6 金秋;劉少崗;;銑削加工中最小夾緊力的計(jì)算[J];工具技術(shù);2010年04期

7 秦國(guó)華;路冬;吳鐵軍;;形狀復(fù)雜零件的裝夾參數(shù)確定算法[J];兵工學(xué)報(bào);2009年12期

8 梅中義;高紅;王運(yùn)巧;;飛機(jī)鋁合金結(jié)構(gòu)件數(shù)控加工變形分析與控制[J];北京航空航天大學(xué)學(xué)報(bào);2009年02期

9 倪麗君;陳蔚芳;;多目標(biāo)的裝夾方案優(yōu)化及變夾緊力優(yōu)化[J];機(jī)械設(shè)計(jì)與制造;2007年07期

10 陳蔚芳;倪麗君;王寧生;;夾具布局和夾緊力的優(yōu)化方法研究[J];中國(guó)機(jī)械工程;2007年12期

相關(guān)博士學(xué)位論文 前1條

1 田韶鵬;基于特征信息傳遞的零件結(jié)構(gòu)設(shè)計(jì)及其工藝幾何分析方法研究[D];華中科技大學(xué);2005年

相關(guān)碩士學(xué)位論文 前3條

1 張傳泰;基于遺傳算法和有限元的工件裝夾優(yōu)化研究[D];大連理工大學(xué);2010年

2 李目;基于變形控制的薄壁件銑削加工參數(shù)優(yōu)化及仿真研究[D];南京航空航天大學(xué);2010年

3 倪麗君;計(jì)算機(jī)輔助夾具設(shè)計(jì)中的裝夾優(yōu)化技術(shù)研究[D];南京航空航天大學(xué);2007年

，

本文編號(hào)：1454058