【正文】
他們傾向于獲得局部最優(yōu)解。一階線性模型,發(fā)展了,從上述的功能關(guān)系用最小二乘法,可派代表作為如下: 在估計(jì)響應(yīng) y1的基礎(chǔ)上,一階方程, Y是衡量表面粗糙度對對數(shù)的規(guī)模 x0=1(虛擬變量)的 x1,x2,x3和 x4分別為對數(shù)變換切削速度,進(jìn)給速度,徑向前角和刀尖半徑 ,∈是實(shí)驗(yàn)誤差和 b值是估計(jì)相應(yīng)的參數(shù)。 (蘇瑞等人 [ 9 ]已開發(fā)出一種表面粗糙度預(yù)測模型,將軟鋼用響應(yīng)面方法,驗(yàn)證生產(chǎn)因素對個別工藝參數(shù)的影響。 瀚斯曼等人 [ 7 ] ,還使用了丹參模式來評估工件材料表面粗糙度對加工表面的影響。不過,研究人員也還有沒有考慮到的影響,如切削條件和刀具幾何同步,而且這些研究都沒有考慮到切削過程的優(yōu)化。分別對鋁合金 L65的 3向銑削過程(面,槽和側(cè)面)進(jìn)行了切削試驗(yàn),并對其中的切削力,表面粗糙度,凹狀加工平面進(jìn)行了測量。因此通過努力,在這篇文章中看到刀具幾何(徑向前角和刀尖半徑)和切削條件(切削速度和進(jìn)給速度) ,表面精整生產(chǎn)過程中端銑中碳鋼的影響。然而,除了切向和徑向力量,徑向前角對電力的消費(fèi)有著重大的影響。 1 導(dǎo)言 端銑是最常用的金屬去除作業(yè)方式,因?yàn)樗軌蚋焖偃コ镔|(zhì)并達(dá)到合理良好的表面質(zhì)量。 besides these studies have not considered the optimization of the cutting process. As end milling is a process which involves a large number f parameters, bined influence of the significant parameters an only be obtained by modelling. Mansour and Abdallaet al. [5] have developed a surface roughness model for the end milling of EN32M (a semifree cutting carbon case hardening steel with improved merchantability). The mathematical model has been developed in terms of cutting speed, feed rate and axial depth of cut. The affect of these parameters on the surface roughness has been carried out using response surface methodology (RSM). A first order equation covering the speed range of 30–35 m/min and a second order equation covering the speed range of 24–38 m/min were developed under dry machining conditions. Alauddin et al. [6] developed a surface roughness model using RSM for the end milling of 190 BHN steel. First and second order models were constructed along with contour graphs for the selection of the proper bination of cutting speed and feed to increase the metal removal rate without sacrificing surface quality. Hasmi et al. [7] also used the RSM model for assessing the influence of the workpiece material on the surface roughness of the machined surfaces. The model was developed for milling operation by conducting experiments on steel specimens. The expression shows, the relationship between the surface roughness and the various parameters。這些參數(shù)對表面粗糙度 的 建立,方差分析 極具意義 。由于這些過程涉及大量的參數(shù),使得難以將關(guān)聯(lián)表面光潔度與其他參數(shù)進(jìn)行實(shí)驗(yàn)。獲得最佳切削參數(shù),是在制造業(yè)是非常關(guān)心的,而經(jīng)濟(jì)的加工操作中及競爭激烈的市場中發(fā)揮了關(guān)鍵作用。表面光潔度一直是一個重要的因素,在機(jī)械加工性能預(yù)測任何加工操作。上下銑方面切削力與右手螺旋角,雖然主要區(qū)別在于表面粗糙度大,但不存在顯著差異。分別制定了一階方程涵蓋的速度范圍為 3035米 /分,一類二階方程涵蓋速度范圍的 2438米 /分的干切削條件。許多方法已經(jīng)被國內(nèi)外文獻(xiàn)報(bào)道,以解決加工 參數(shù)優(yōu)化問題。這個數(shù)學(xué)模型已被作為目標(biāo)函數(shù)和優(yōu)化進(jìn)行了借助遺傳算法 響應(yīng)面分析法(丹參)是一種有益建模和分析問題的組合數(shù)學(xué)和統(tǒng)計(jì)技術(shù)的方法,在這幾個獨(dú)立變量的影響力供養(yǎng)變或反應(yīng)。傳統(tǒng)方法的優(yōu)化和搜索并不收費(fèi),以及點(diǎn)多面廣的問題域。加文來根據(jù)。有效性選定的模型用于優(yōu)化工藝參數(shù),是經(jīng)過檢驗(yàn)的幫助下統(tǒng)計(jì)測試,如 F檢驗(yàn),卡方檢驗(yàn)等 [10] 。 3 方法論 在這項(xiàng)工作中,數(shù)學(xué)模型已經(jīng)開發(fā)使用的實(shí)驗(yàn)結(jié)果與幫助 響應(yīng)面方法論。上述模式并沒有考慮到對刀具幾何形狀對表面粗糙度的影響。數(shù)學(xué)模型已經(jīng)研制成功,可用在計(jì)算切削速度,進(jìn)給速度和軸向切深。對主軸速度,切削深度和進(jìn)給速度對切削力和表面粗糙度的影響進(jìn)行了研究。 12 2回顧 建模過程與優(yōu)化,是兩部很重要的問題,在制造業(yè)。因此,發(fā)展一個很好的模式應(yīng)當(dāng)包含徑向前角和刀尖半徑連同其他相關(guān)因素。因此,測量表面光潔度,可預(yù)測加工性能。第一次和第二次 為建立 數(shù)學(xué)模型,從加工參數(shù) 方面 ,制訂了表面粗糙度預(yù)測響應(yīng)面方法(丹參) ,在此基礎(chǔ)上的實(shí)驗(yàn)結(jié)果。在當(dāng)前的工作中,實(shí)驗(yàn)性研究 的 進(jìn)行 已 看到刀具幾何(徑向前角和刀尖半徑)和切削條件(切削速度和進(jìn)給速度) ,對加工性能, 和 端銑中碳鋼 影響效果 。此外,表面光潔度還影響到機(jī)械性能,如疲勞性能,磨損,腐蝕,潤滑和導(dǎo)電性。此外,研究人員 [ 1 ]也指出,在不影響表面光潔度情況下,刀尖半徑發(fā)揮著重要作用。數(shù)學(xué)模型的進(jìn)一步利用,尋找最佳的工藝參數(shù),并采用遺傳算法可促進(jìn)更大發(fā)展。切削性能的立銑刀則被評定采用方差分析。曼蘇爾和艾布達(dá)萊特基地 [ 5 ]已開發(fā)出一種表面粗糙度模式,為年底銑 EN32M(半自由切削碳硬化鋼并改進(jìn)適銷性)。表明表面粗糙度及各項(xiàng)參數(shù),即切削速度,飼料和切削深度之間的關(guān)系。考慮到上述情況,已試圖在這方面的工作,以發(fā)展一個表面粗糙度的模型與工具幾何形狀 13 和切削條件,在此基礎(chǔ)上的實(shí)驗(yàn)結(jié)果,然后再優(yōu)化,在端銑操作中,它為選拔這些參數(shù)給定了限制。參數(shù),即本 B0中, B1, B2的, B3的, B4的, B12的, b23的, b14等,要估計(jì)由最小二乘法。因此,決定使用遺傳算法作為優(yōu)化技術(shù)。傳統(tǒng)的技術(shù)是沒有效率的時(shí)候,實(shí)際的搜索空間過大。數(shù)學(xué)模型常用的是代表: 而 Y是加工回應(yīng), ?是響應(yīng)函數(shù)和 S, f, α , R的銑削變數(shù)和∈是錯誤,通常是發(fā)給約觀測響應(yīng) y為零的意思。喬恩和賈殷 [ 8 ]用神經(jīng)網(wǎng)絡(luò)建模和優(yōu)化加工條件。 艾爾艾丁等人 [ 6 ]開發(fā)出一種表面粗糙度模型,用丹參,為端銑 190BHN鋼。 拜佑密等人 [ 4 ]研究過工具對旋轉(zhuǎn)角度,進(jìn)給速度和切削速度在機(jī)械工藝參數(shù)(壓力,摩擦參數(shù))的影響,為端銑操作常用三種商用工件材料, 11L17易切削鋼, 62353易切削黃銅和鋁 2024年使用單一槽高速鋼立銑刀。為了開發(fā)和優(yōu)化表面粗糙度模型,有必要了解目前在這方面的工作的狀況。在材料去除過程中,不當(dāng)?shù)倪x擇切削條件造成的表面粗糙 度高和尺寸誤差,它甚至可能發(fā)生動力現(xiàn)象:由于自動興奮的震動,可以設(shè)定在 [ 2 ] 。在這個過程中建模有助于更好的理解。 通過 嘗試也取得了優(yōu)化表面粗糙度預(yù)測模型,采用遺傳算法( GA ) 。 1 附錄 附錄 1: 英文原文 Selection of optimum tool geometry and cutting conditions using a surface roughness prediction model for end milling Abstract Influence of tool geometry on the quality of surface produced is well known and hence any attempt to assess the performance of end milling should include the tool geometry. In the present work, experimental studies have been conducted to see the effect of tool geometry (radial rake angle and nose radius) and cutting conditions (cutting speed and feed rate) on the machining performance during end milling of medium carbon steel. The first and second order mathematical models, in terms of machining parameters, were developed for surface roughness prediction using response surface methodology (RSM) on the basis of experimental results. The model selected for optimization has been validated with the Chi square test. The significance of these parameters on surface roughness has been established with analysis of variance. An attempt has also been made to optimize the surface roughness prediction model using geic algorithms (GA). The GA program gives minimum values of surface roughness and their respective optimal conditions. 1 Introduction End milling is one of the most monly used metal removal operations in industry because of its ability to remove material faster giving reasonably good surface quality. It is used in a variety of manufacturing industries including aerospace and automotive sectors, where quality is an important factor in the production of slots, pockets, precision moulds and dies. Greater attention is given to dimensional accuracy and surface roughness of products by the industry these days. Moreover, surface finish influences mechanical properties such as fatigue behaviour, wear, corrosion, lubrication and electrical conductivity. Thus, measuring and characterizing surface finish can be considered for predicting machining performance. Surface finish resulting from turning operations has traditionally received considerable research attention, where as that of machining processes using multipoint cutters, requires attention by researchers. As these processes involve large number of parameters,