超聲磨削裝置結(jié)構(gòu)設計【全套含有CAD圖紙三維建?！?/h1>
超聲磨削裝置結(jié)構(gòu)設計【全套含有CAD圖紙三維建?！?全套含有CAD圖紙三維建模,超聲,磨削,裝置,結(jié)構(gòu)設計,全套,含有,CAD,圖紙,三維,建模
附錄A
Dynamic Simulation of an Injection Molding
Author1, Author2, Author3.
Applied Thermal Engineering, 2016, 8(6):556-568.
Abstract: An integrated design method is discussed which thoroughly considers related parameters of the various subsystems in order to optimize the overall system that mainly consists of opto--mechanical structure CAD, CAE and the integrated information platform PDM. Based on the parameter drive of the virtual main model, the method focuses on the model transformation and data share among different design and analysis steps, and so the concurrent simulation and design optimization are carried out. As an example of application, the integrated design for a large-scale opto-mechanical structure is introduced, including optical design, structure design and analysis, which further validates the advantages of the method. Due to comprehensive consideration of the design and analysis process by CAD and CAE based on PDM, the integrated design well attains the structure optimization with high efficiency.
Keywords: integrated design; CAD/CAE; large-scale structure; optical instrument.
1. Introduction
The analysis of products integrating different technologies, e.g. mechanical, hydraulic and controls systems, becomes more and more feasible with the constant development of simulation software and more performing computer hardware. The combination of specialized software packages is possible and allows the simulation of so-called mechatronic systems. If in the past such tools were mainly used in the aeronautic and automobile industries, they now find their way into more common engineering applications. In this case,the dynamic characteristics of the clamp unit of an injection molding machine from HUSKY is investigated. For this purpose, the finite-element (FE) program ANSYS, the multi-body simulation (MBS) software ADAMS, the fluid power simulation software DSHplus and the controls design tool MATLAB/Simulink are used. Combining these different simulation tools and applying them to the damp unit, we can analyze and understand the dynamic behavior of the machine and the interaction between the different sub-systems. This is necessary to improve the performances, like reducing wear, cycle time or noise, or avoiding premature failure of parts.
The damp unit Is the mechanism that doses and opens the mold and keeps it effectively closed during the injection and the holding-pressure stages. The HUSKY OUADLOC' damp is a two-platen hydraulic damping system. The main components are the moving platen, the clamp base and the stationary platen with the four tie bars. The platen locking and the damping force are realized with the damp pistons, which are integrated in the moving platen. The damp pistons can be rotated by 45' to engage the tie bar teeth in order to lock the moving platen in its position. The main functions of the damp unit are actuated hydraulically;hydraulic pressure is applied to the damp pistons to generate the necessary damping force and two hydraulic cylinders are used for the displacement of the moving platen. [1]
Figure1: HUSKY QUADLOC clamp unit
The analysis focuses on two aspects: first, the quantification of the forces acting on the pads between the damp base and the foundation in order to foresee and prevent any creep of the machine during operation, and second, the optimization of the stroke command signal in order to reduce the overall cycle time. Therefore the simulation model Is limited to the moving platen stroke.
2． Simulation Models
The mechanical, hydraulic and controls systems are modeled in ADAMS, DSHplus and MATLAB/Simulink, respectively. ADAMS gives the possibility to Include non-standard phenomena by linking user-written FORTRAN or C subroutines In the model. DSHplus uses this feature to make a co-simulation between both programs possible. Besides, ADAMS disposes of a plug-In that allows the user to conned the MBS model with Simulink. Thus it is possible to link the three simulation tools and simulate the complete machine. There are two
possibilities for the computation: first, each program Integrates its own set of differential equations and exchanges the necessary parameters with the other ones, second, the three models are completely integrated and only the Slmulink solver Integrates the differential equations set.
Figure2:co-simulation of moving platen stroke
Additionally, the flexibility of mechanical parts can be included in ADAMS. We use ANSYS to generate the necessary FE models and to reduce these large models to a few degrees of freedom before being integrated Into ADAMS. The reduction method Is based on the component mode synthesis technique Introduced by Craig and Bampton.
Mechanical Model
The rgid-body model of the damp unit Is very simple and consists only of two parts: the moving platen and the stationary platen with damp base and tie bars (refer to figure 4). The damp base is fixed with linear spring-damper elements to the ground and the sliding of the moving platen is modeled with contact statements. Basically, the contact statement is a nonlinear spring-damper element where the force is proportional to the penetration depth x and the penetration velocity it :x
k and d are the contact stiffness and damping coefficients, respectively and a is an exponent that for numerical reasons should be chosen greater then 1. If there is no penetration, then no force is applied, otherwise the location of contact, the normals at the points of contact and the force acting between both parts are computed. The statement also includes a Coulomb friction model. The transition from the static to the dynamic friction coefficient Is based on the relative velocity of the two colliding geometries. Finally, the two stroke cylinder forces and a contact statement are defined between both platens. In order to have a more accurate mechanical model, also In view of a more realistic distribution of the forces on the damp-base pads, the different parts are included as flexible bodies. These flexible bodies are derived from FE models that are reduced before being imported. The reduction method Implemented In ADAMS is based on the component mode synthesis (CMS) technique, i.e. the deformation is written as a linear combination of mode shapes. In ADAMS, constraint modes and fixed-boundary normal modes are used to generate the component-made matrix 0. This approach is known as the Craig-Bampton method. In the following, the basic principles and steps of Integrating flexible bodies In ADAMS are shown; a more detailed theoretical presentation can be found in
First of all, a FE model Is created that is detailed enough to comedy represent the mode shapes of interest. The user has then to choose the nodes that serve as interface to the MBS model. The kinematic constraints or forces are applied to these boundary nodes; the remaining nodes are referred to as interior nodes.
By fixing the degrees of freedom (DOF) u, of the boundary nodes and solving an elgenproblem, we get the fixed-bounder, normal modes d>r. This normal mode set is usually truncated. The constraint modes dc are defined as the static deformation of the structure when a unit displacement Is applied to one DOF of a boundary node while the remaining DOF of the boundary nodes are restrained (Guyan reduction). Finally the component mode reduction matrix m Is defined by the normal modes set φand the constraint modes set d>r.
The relationship between the physical displacement coordinates u and the component generalized coordinates q is
With equation (2) the generally large number of physical DOF u is drastically reduced to few mixed physical and modal DOF q.
However, the Craig-Bampton modal basis q has certain disadvantages that make it sometimes difficult to directly use it in a multi-body simulation. The set of constraint modes contains the 6 rigid-body DOF that must be replaced by the large displacement DOF of the local body reference frame in ADAMS. They have to be removed and therefore the component-mode matrix Is transformed by solving the eigenproblem
where K and M are the reduced stiffness and mass matrix, respectively. The manipulation results In a modal basis where q - N4; N containing the elgenvectors from equation (3).
The last step Is a purely mathematical approach and does not further reduce the number of DOF. The new modal basis q has no direct physical meaning anymore but addresses the problems mentioned above
Table 1: First 13 eigenfequencies of the moving platen
The motion of a flexible body is derived from the same equation as for a rigid-body, I.e. Lagrange's equations. In order to calculate the kinetic and potential energy, the position and velocity of an arbitrary point on the flexible body Is expressed with the generalized coordinates.
M the generalized mass matrix depending on,
K the generalized stiffness matrix only depending on q
V the gravitational energy,
D the damping matrix defined using modal damping ratios Is
Q the kinematic constraint equations applied to the flexible body.
Adding flexible bodies to an ADAMS model is quite straightforward. Nevertheless, there are some limitations regarding forces and joints that can be defined to them. Especially the problem of a moving force on a flexible body.
I.e. moving platen sliding on clamp base, is an open Issue in multi-body dynamics. However, there are "standard" workarounds which work well and which have proven their usefulness.
The technique Implemented in our flexible-body model is based on the contact statement mentioned above. Basically it works as follows: for each of the selected nodes along the sliding path, a force is computed according to equation
That depends on the relative vertical position y and velocity y of the node to the moving platen.
However, the force is only activated when the node and the moving platen effectively overlap. In fad, It is weighted by a function that depends on the horizontal distance x between the node and the moving platen.
The force is ramped up from zero or ramped down to zero In order to guarantee a smooth application and to minimize any discontinuities.
No contact points and contact normals are computed. The distance and velocity of a node relative to the moving platen are taken In the global coordinate system and the contact and friction forces are always collinear with the coordinate system unit vectors.
Nevertheless, this approach gives acceptable results, as the deformation of the damp base is very small. A Coulomb friction force is applied in the same way.
Figure 3: moving platen sliding model
The main disadvantage is that a huge number of Interface nodes are needed to have any sound representation of the moving contact forces. Unfortunately, this gives a huge number of flexible-body DOF and therefore unacceptable computation times. Now, instead of defining these nodes as interface nodes, they remain interior nodes. From a purely theoretical point of view, the accuracy of the results is not guaranteed anymore when using interior nodes as interface nodes. However, choosing more normal modes can reduce the error. The comparison of a model using interior nodes for the moving platen sliding with one using interface nodes shows a very 9000 Compliance Of the results While having a much taster computation time. Therefore we used this model for the following simulations. Other methods were not tested but some of them are presented in (3) and (4).
The flexible bodies are created in ANSYS. Simplified CAD geometries of both platens were imported In the FE program and meshed automatically with tetrahedral SOLID187 elements. The damp base was generated 'manually" with SHELL63 elements and the tie bars are modeled with BEAM4 elements. Stationary platen, clamp base and tie bars were put together b one assembly and the different components connected via spring-damper elements (COMBIN14). A macro for the computation of the modified Craig-Brampton basis is available In ANSYS. It allows the user to specify the Interface nodes and the number of normal modes. The resulting modal basis Is written to a file that has to be imported Into ADAMS.
The ANSYS macro automatically selects the six DOF of each interface node as u}. However, it is not imperative to select all the six DOF. This allows us to furthermore reduce the number of static modes and thus the number of flexible-body DOF. The macro has been changed accordingly to select only the effectively required DOF ua Finally, the moving platen has 29 flexible-body DOF and the stationary platen, clamp base and tie bars assembly has 95 flexible-body DOF.
Figure4:ADAMS flexible-body model
附錄B
注塑機的動態(tài)模擬
Author1, Author2, Author3.
Applied Thermal Engineering, 2016, 8(6):556-568
摘要：討論了充分考慮相關的參數(shù)是一個集成的設計方法為各子系統(tǒng)優(yōu)化的整體系統(tǒng)，主要由光電—機械結(jié)構(gòu)CAD，CAE與PDM集成信息平臺。基于的虛擬模型的參數(shù)驅(qū)動的方法，側(cè)重于模式的轉(zhuǎn)型的設計和分析的步驟之間的數(shù)據(jù)共享，所以并行仿的設計進行優(yōu)化。作為應用實例，綜合設計介紹了一種大型光學機械結(jié)構(gòu)，包括光學設計，結(jié)構(gòu)設計與分析，進一步驗證了該方法的優(yōu)點。由于分析了基于PDM和CAD和CAE過程的設計，集成設計達到結(jié)構(gòu)優(yōu)化效率高。
關鍵詞：集成設計：CAD / CAE：大規(guī)模的結(jié)構(gòu)：光學儀器
1. 介紹
產(chǎn)品整體不同技術(shù)的分析，例如，機械、液壓、控制系統(tǒng)，模擬軟件可持續(xù)發(fā)展和更多計算機硬件操作變得越來越可行。結(jié)合特殊的軟件程序包是可以和允許對所謂的機電一體化系統(tǒng)模擬的。如果在過去這些工具被應用與航空和汽車工業(yè)中，那么他們現(xiàn)在會找到更多應用工程技術(shù)的相同點。因此，被研究的是HUSKY注塑機夾緊裝置的動態(tài)特性。ANSYS有限元（FE）程序，ADAMS多維模擬軟件，DSHplus流體動力模擬軟件和MATLAB仿真設計控制工具都被用于這個目。結(jié)合這些不同的模擬工具并應用它們于合模機構(gòu)，我們就能分析和理解機器的動態(tài)行為和不同子系統(tǒng)之間的聯(lián)系。這就需要去提高性能，像減少磨損、循環(huán)時間或噪音，或者避免部件早期的錯誤。
合模機構(gòu)是一個開啟與合上模具并能夠在注塑和保壓階段有效的緊閉的機構(gòu)。HUSKY QUADLOCTM合模機構(gòu)是一個二板式液壓合模系統(tǒng)。主要由動模板，合模工作臺，定模板和四個拉桿構(gòu)成。模板鎖定和合模壓力是通過動模板整合的合模栓塞實現(xiàn)的。合模栓塞可以旋轉(zhuǎn)45度去嚙合拉桿螺紋為了保證動模板在注塑位置上。合模機構(gòu)的主要功能是驅(qū)動液壓油：液體壓力被施加在合模栓塞上去產(chǎn)生需要的合模壓力并且兩個油缸被用于動模板的移動[1]。
分析的焦點集中在兩個方面：第一，壓力作用在工作臺之間的襯墊上和為了預見的基礎并阻止機器在運轉(zhuǎn)中爬行。第二，為了減少總體循環(huán)時間的最優(yōu)化的噴射控制信號。因此，模擬模型被限制移動模版的注射。
2. 模擬模型
機械，液壓，控制系統(tǒng)被分別的在ADAMS, DSHplus和MATLAB仿真中模擬。ADAMS可能包括由鏈接FORTRAN書面使用和C程序在模型中引起的不標準的現(xiàn)象。DSHplus利用這個特點在兩個可能的程序上建立了一個co模擬。另外，ADAMS處理插件允許使用者用模擬鏈接MBS模型。因此，鏈接三個模擬工具和模擬整個機器是可能的。這里有兩個可能估計：第一。各個整合它自己不平衡的部分并和其他的部分交換參數(shù)。第二，三個模型被完全的整合并只有模擬求解整合不同的因素部分。
圖1 HUSKY QUADLOCTM合模機構(gòu)
此外，柔性的機械部件可以包括在ADAMS中。我們用ANSYS產(chǎn)生必要的FE模式，并在被納入ADAMS之前降低這些大型模型自由度。
減少自由度方法是基于引用Craig和bampton的組件式合成技術(shù)這是必要的。
圖2 模型的聯(lián)合仿真
2.力學模型
合模機構(gòu)的剛性模型很簡單,只分為兩個部分: 移動模板和固定模板和合模工作臺還有拉桿（參見圖4）。合模工作臺是固定在地面上裝有線性彈簧-阻尼單元和滑動的動模板構(gòu)成報表式的模型?；旧希瑘蟊硎绞且粋€穿透深度X和滲透速率X與壓力成正比的非線性彈簧-阻尼單元K和d分別的是接觸剛度和阻尼系數(shù)， e是一個指數(shù)，由于數(shù)值原因應選擇大于1。如果沒有滲透，那么就沒有壓力作用，否則就會有接觸，正常應在接觸點和作用力兩部分之間計算。該報表還包括了一個庫侖摩擦模型。從靜態(tài)到動態(tài)的摩擦系數(shù)的變化，是基于相對速度的兩個幾何碰撞。最終，在兩個模板之間定義了兩個液壓缸的壓力和接觸報表。為了有一個更準確的力學模型，同時，鑒于更為實際的分配作用在合模工作臺上的力，他的不同部分被列為柔性機構(gòu)。這些柔性機構(gòu)是來自在被輸入之前減少了的FE模式。這種在ADAMS里減少方法的實施是基于組件式頻率合成器( CMS )中的技術(shù)，即變形是被看作是線性組合模式形狀。在ADAMS里，約束模式和固定邊界的正常模式是用來生成組件矩陣模式Ф。這種方法被稱為Craig-Bampton方法。接下來，在ADAMS中基本的原則和柔性體積分的步驟被展示：更詳細的理論介紹可以在[2]式中看到。一個FE模型的建立可以足夠詳細的正確表達出模型的重要性。操作者這時可以選擇充當MBS模型的邊界作為節(jié)點。被約束的運動和力被施加在這些邊界節(jié)點上；其余的節(jié)點稱為內(nèi)部節(jié)點。由固定在邊界節(jié)點上的自由度（DOF）和求解特征，我們得到固定邊界常態(tài)模量，這個正常的設定模式通常是截斷。約束模量被定義為當其余邊界節(jié)點自由度都受約束時，一個元件施加在一個邊界節(jié)點的一個自由度的靜態(tài)結(jié)構(gòu)的變形。最后組成還原矩陣的模式被解釋為常態(tài)設定模式和約束設定模式。實際位移坐標u和組成廣義坐標q之間的關系是
在方程（2）中，普遍的大量的自由度u被徹底的減少到只有少數(shù)混合現(xiàn)實和虛擬的自由度q。然而，Craig-Bampton的基礎形態(tài)q也有一些毫無疑問的缺點,使有時在多維仿真中難以直接利用它。這套約束模式包含6個剛體自由度，必須取而代之在ADAMS中主體局部的大位移自由度。它們必須被移除，因此在求解方程中，結(jié)構(gòu)模型的矩陣被轉(zhuǎn)化。
其中k和m在矩陣中分別代表降低的剛度和質(zhì)量。在基礎模量上處理的結(jié)果是；N包含的特征在方程（3）中被表現(xiàn)。
最后一步,是一個純粹的數(shù)學方法,并沒有進一步減少自由度的數(shù)量。新的基礎模量就沒有了直接的物理意義了,而是針對上述的問題。
柔性體的運動模型是與剛性體來自同一方程，即拉格朗日方程。為了計算動能和勢能，柔性體上任意點的位置和速度是由廣義坐標表示的。
x，y，z，Ψ，θ，Φ，為局部參照系附加彈性體和描述六個剛體模式的坐標。最終形式的運動方程是
其中ξ 為廣義坐標，
M 依賴于ξ的廣義質(zhì)量矩陣，
K 只取決于的廣義剛度矩陣，
D 阻尼矩陣定義模態(tài)阻尼§，因此D是對角線，
Ψ 適用于柔性體運動學約束方程，
λ 拉格朗日乘數(shù)，
Q 廣義應用的力。
另外，一個柔性體在ADAMS模式下相當?shù)闹苯亓水?。不過，也有一些力量和關節(jié)限制，我們可以界定給它們。特別是在一個柔性體上摩擦力的問題，即動模板在工作臺上滑動，是一個多維動力學的開放性問題。然而，它們制定的標準使得運行好并且被證明有用。
在我們的柔性模型中，技術(shù)的執(zhí)行是基于上述的表訴。基本上它的模式如下:對于每一個沿滑動路徑選定的節(jié)點，一個力根據(jù)作用在動模板上垂直位置和速度的關系的方程（1）進行計算。然而，力只是在當節(jié)點和動模板的重疊部分起作用時才作用。事實上，重量的函數(shù)是基于節(jié)點和動模板之間的水平距離。力從零斜線上升或斜線降低到零是為了保證應用能順利和盡量減少任何間斷。沒有接觸點和接觸平均值計算。節(jié)點的距離和速度相對于動模板應采用總的坐標系統(tǒng)和適用于矢量單元坐標的接觸和摩擦力。不過，這種做法是能夠接受的結(jié)果，正如變形的合?；鶖?shù)很小。庫侖摩擦力適用于同樣的方法。
主要缺點是大量的分界節(jié)點都需要有充分代表性的移動接觸力。不幸的是，這有太多的柔性體自由度和并且無法計算次數(shù)?，F(xiàn)在，并不是把這些節(jié)點作為邊界節(jié)點，他們?nèi)允莾?nèi)部節(jié)點。從純理論的角度看，當使用內(nèi)部節(jié)點作為邊界節(jié)點時結(jié)果的準確性無法保證。然而，更多的選擇標準模式，可以減少誤差。比較采用內(nèi)節(jié)點的模型對對應采用表面節(jié)點的滑動模板會有一個非常一致的結(jié)果，同時還會加快計算速度。因此，我們使用這一模型進行模擬后，其他方法都沒有測試過，但它們中的一些曾在上述中
圖3 動模板彈性模型
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