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to 20 C and the Atompercent (weight percent) to .At this time the user will initialize the phase position of the object.17) Click on the Objects Tabs, then click on the Elements Data Icon and clickon the Transformation Tab to see where the position of the objectmaterial is defined. (Figure )Figure Element windows with Transformation dataThis window specifies several values in for the object phase position. Thevalue, VOLFC, is the volume fraction of a specific phase in the object. The sum of the volume fraction values for all the phases at any time must be equal to unity. The user can initialize the object to be pure binate at the beginning of the simulation by clicking on the VOLFC value for the Binate phase and thenclicking on the Initialize Values icon directly to the left. Click on the Binatebox to make it the active box and click on the Initialize button (I) next to thetable. Set the value to 1 and click on the Ok button. Initialize the VOLFSvariable for Binate to be unity as well, following the same procedure. TheVOLFS variable specifies the transformation limit of a given phase. Thus, byspecifying a value for VOLFS of , 100 % of the Binate is allowed totransform into Austenite.18) Press Ok in the Initialize Elements window and then press Ok in theElements window.19) Click on the Properties icon in the Objects window and change the EPInitial Guess to Use previous step solution.20) Click Ok in the Object Properties window.Question: What is meant by EP Initial Guess?In order to solve an FEM problem, a numerical solver is required. DEFORM? uses NewtonRapson or Quasi NewtonRap son to solve for the deformation of elasticplastic , for both of these methods, an initial guess is required. As the initial guess gets better, the speed and likeness of convergence increases. By default, the FEM engine uses a rigidplastic Calculation as the initial guess for an elasticplastic material. Another method that DEFORM?May implement is to perform the calculation for an elastic material. The third method is to use the result from the previous step as the initial guess. This is usually the best method if the deformation in the object is small.Object 2:This object will be used for the sole purpose of constraining object 1.1) In the Objects window, add another object by clicking on the Add Object icon. This object number will default to 2.2) Select this object 2 and change the name of this object to Plane.3) Click on the Geometry icon in the Objects window and click on the Load IGES file icon.4) Load the file Plane. IGS as object 2 and press Ok in the Geometry window. Your screen should look like Figure .The purpose of this object is to serve as a plane of symmetry where no material may cross. The key to making this act as a true plane of symmetry is to set the interface heat transfer to zero, the friction to zero and the placing a no separation criteria between the two objects. These parameters will be prescribed later.5) Click Ok in the Objects window.中文翻譯 創(chuàng)造一個(gè)新的問題 創(chuàng)建一個(gè)目錄稱為變換,改變到那個(gè)目錄。雷聲老師的悉心輔導(dǎo)使我在畢業(yè)論文中少走了許多彎路,順利完成設(shè)計(jì)任務(wù)。論文的完成也就意味著大學(xué)生涯的結(jié)束。因此模具在很大程度上決定企業(yè)在市場競爭中的應(yīng)變能力,模具成型己成為現(xiàn)代工業(yè)生產(chǎn)的重要手段和工藝發(fā)展方向。 課題展望 模具是現(xiàn)代工業(yè)生產(chǎn)中使用極為廣泛的工藝裝備。適用于中小型薄料沖裁。故沖件精度較高,刃口強(qiáng)度也較好。由以上分析可知對于該復(fù)合模具的沖壓凸模采用臺(tái)直通凸模結(jié)構(gòu)。2)臺(tái)階式凸模臺(tái)階式凸模,其工作部分與固定部分的形狀與尺寸不同。 凸模、凹模、凸凹模、彎曲模設(shè)計(jì) 凸模凸模的形式一般有兩種:直通式凸模和臺(tái)階式凸模。擋料銷的選擇 擋料銷主要用于定位,保證條料有準(zhǔn)確的送料步距。頂件塊與凸凹模的配合(1)沖裁件的內(nèi)形尺寸較小、外形尺寸較簡單時(shí),頂件塊外形與凹模之間采用間隙配合H8/f8,頂件塊內(nèi)孔與凸模采用非配合工序(外導(dǎo)向)。裝在上模內(nèi)的出件裝置稱為推件裝置,裝在下模內(nèi)的稱為頂件裝置。(2) 彈性推件裝置利用安裝在上模內(nèi)的彈性元件的彈力來給推件塊一個(gè)力,彈性元件多采用彈簧和橡膠。(2)螺釘規(guī)格按下表選用表51螺釘規(guī)格的選用凹模厚度mm螺釘規(guī)格凹模厚度mm螺釘規(guī)格 凹模厚度mm螺釘規(guī)格≤13MM51925MM832MM121319MM62532MM10(3) 各被聯(lián)接件的銷孔應(yīng)配合加工,以保證精度出件裝置的作用是從凹模內(nèi)卸下沖件或廢料。螺釘和銷釘和銷釘都是標(biāo)準(zhǔn)件。壓入式模柄,主要用于上模座較厚而又沒有開設(shè)推板孔或上模具比較重合的場合。故采用彈性卸料裝置。根據(jù)上面的設(shè)計(jì)和計(jì)算,并考慮經(jīng)濟(jì)性,選用后側(cè)導(dǎo)柱模架。選模架尺寸時(shí)要根據(jù)凹模的輪廓尺寸考慮,一般在長度上及寬度上都應(yīng)比凹模大30~40㎜。間隙過大,回彈增大,工件的誤差增大;間隙過小,則會(huì)使零件邊部壁厚減薄,同時(shí)會(huì)降低凹模壽命。生產(chǎn)中,按材料的厚度決定凹模圓角半徑: 51,取。查表45: 直徑為16mm = =(3)孔中心距第5章 彎曲模工作部分的設(shè)計(jì)計(jì)算 凸、凹模的圓角半徑取凸模圓角半徑等于彎曲件的彎曲半徑r=3mm??砂碔T16IT17精度選取,或者?。?/41/6)Δ。其計(jì)算公式為: 414 415 式中:、沖孔凸凹模直徑(mm);沖孔時(shí)內(nèi)徑的最小極限尺寸(mm);Δ沖裁件制造公差(mm);凸凹模最小初始雙面間隙(mm);χ在模具設(shè)計(jì)中考慮磨損所取的系數(shù),為的是使沖裁件的實(shí)際尺寸盡量接近沖裁件公差帶的中間尺寸。一般比沖裁件的精度高2~3級(jí),如果對刃口精度要求過高,勢必增加模具制造成本和難度,生產(chǎn)周期長;如果對刃口精度要求過低,沖制的零件不合格。因落料件的尺寸等于凹模尺寸,而沖孔件尺寸等于凸模尺寸,因此,計(jì)算模具刃口尺寸時(shí),應(yīng)按落料和沖孔兩種情況分別處理。4176。5176。在沖壓實(shí)際生產(chǎn)中,主要根據(jù)沖裁件斷面質(zhì)量、尺寸精度和模具壽命這三個(gè)因素綜合考慮,給間隙規(guī)定一個(gè)范圍值。模具壽命分為刃磨壽命和模具總壽命。 411式中:凸模尺寸 凹模尺寸圖42沖裁模間隙 間隙的重要性間隙是影響沖裁件質(zhì)量的主要因素。V型接觸彎曲的計(jì)算公式如下: 48式中:b彎曲件寬度; t板料厚度; σ板料的抗拉強(qiáng)度; r凸模圓角半徑; K安全系數(shù),取K=由零件圖可知彎曲件寬度b=16mm,板料厚度t=2mm,取凸模圓角半徑r=3mm,查資料可得板料抗拉強(qiáng)度σ=280MP,可得出彎曲力:P=16mm2mm280MP/(3mm+2mm)= 沖裁模具壓力中心沖裁模的壓力中心就是沖裁過程中沖裁力系合力作用點(diǎn)。JA2135開式固定臺(tái)壓力機(jī)公稱壓力350kN,滑塊行程130mm,最大閉合高度280mm。n=h/t,h為凹模洞口的直壁高度;t為板料厚度。從凸模上卸下箍著的料所需的力稱卸料力;將梗塞在凹模上的料順沖裁方向推出所需要的力稱推件力;逆沖裁方向?qū)⒘蠌陌寄?nèi)頂出所需要的力稱頂件力,影響這些力的因素很多主要有材料的力學(xué)性能、材料的厚度、模具的間隙、凹模洞口的結(jié)構(gòu)、搭邊大小、潤換情況、制件的形狀和尺寸等。用普通平刃口模具沖裁時(shí),其沖裁力F一般按下式計(jì)算: 42式中:F沖裁力(N)。 排樣3的材料利用率η3=≈63%,利用率高,故采用第三種排樣方式 計(jì)算沖壓力沖裁力是選擇壓力機(jī)公稱噸位和進(jìn)行模具設(shè)計(jì)的依據(jù)。應(yīng)盡量選條料寬、進(jìn)距小的排樣方法;,模具壽命較高;。它決定于沖壓方式和排樣方式。h—進(jìn)距(mm)。因此,排樣是沖裁工藝與模具設(shè)計(jì)中的一項(xiàng)很重要的工作。先進(jìn)行落料,再?zèng)_孔,最后完成壓彎工序。 2)先落料, 后沖孔, 最后壓彎, 用3 副簡單模完成, 其優(yōu)點(diǎn)是模具簡單, 易制造, 沖件質(zhì)量好,