VFRIC界面的幫助文檔內容

1、精選優(yōu)質文檔-傾情為你奉上1.2.4 VFRIC Abaqus User Subroutines Reference ManualUser subroutine to define frictional behavior for contact surfacesOverviewUser subroutine :Ø can be used to define the frictional behavior between contact pair surfaces;能夠用來定義接觸對表面間的摩擦行為；Ø can be used when the classical

2、Coulomb friction model is too restrictive and a more complex definition of shear transmission between contacting surfaces is required;能夠在經典的庫倫摩擦模型太具限制性，并且接觸表面之間需要一個更為復雜的剪切傳輸的定義時使用；Ø must provide the entire definition of shear interaction between the contacting surfaces;必須在接觸表面之間提供完整的“交互剪切”的定義；&

3、#216; can use and update solution-dependent state variables;可以使用并更新基于解的狀態(tài)變量；Ø cannot be used in conjunction with softened tangential surface behavior; and不能夠與軟化的切向表面行為一起使用；Ø cannot be used with the general contact algorithm.不能與通用接觸算法一塊使用。通用接觸算法只可以被用于三維表面；Two-dimensional surfaces cannot be

4、used with the general contact algorithm.二維表面不能與通用接觸算法一起使用TerminologyThe use of user subroutine requires familiarity with the following terminology.使用子程序要求熟悉下列術語。Surface node numbers 表面節(jié)點編號The “surface node number” refers to the position of a particular node in the list of nodes on the surface. For e

5、xample, there are nSlvNod nodes on the slave surface. Number n, n=1, 2 . nSlvNod, is the surface node number of the nth node in this list; jSlvUid(n) is the user-defined global number of this node. An Abaqus/Explicit model can be defined in terms of an assembly of part instances (see ). In such mode

6、ls a node number in jSlvUid is an internally generated node number. If the original node number and part instance name are required, call the utility routine VGETPARTINFO (see ). “表面節(jié)點編號”指的是表面上節(jié)點列表里一個特殊點的位置。例如，在從接觸面上有nSlvNod個節(jié)點。編號n，n=1,2, . nSlvNod，是該節(jié)點列表里第n個節(jié)點的節(jié)點編號；jSlvUid(n)是該節(jié)點用戶自定義的全局編號。Abaqus/E

7、xplicit模型可以按照零件實體的安裝來定義（see ）。在這樣的模型里，jSlvUid里的節(jié)點編號是一個內部生成的節(jié)點編號。如果要求原始節(jié)點編號和零件實體的名字，則調用實用程序VGETPARTINFO。Contact points 接觸點The nodes on the slave surface that are in contact in the current time increment are defined as “contact points.” The number of contact points is passed into this subroutine as nC

8、ontact. The array jConSlvid(nContact) gives the surface node numbers for the contact points. 從接觸面上的那些在當前時間增量接觸的節(jié)點被定義為“接觸點”。接觸點的數量作為nContact被傳到子程序中。數組jConSlvid(nContact) 給出了接觸點的表面節(jié)點編號。Local coordinate system 局部坐標系A local coordinate system is defined for each contact point to facilitate specification

9、of frictional forces and incremental slips. The local 1-direction for both two-dimensional and three-dimensional contact is tangential to the master surface, and it is defined by, where is the incremental slip vector. The incremental slip vector used to define corresponds to the incremental slip in

10、the current time increment for penalty contact and the predicted incremental slip for kinematic contact. The master surface normal direction, n, is the local 2-direction for two-dimensional contact and the local 3-direction for three-dimensional contact. The local 2-direction for three-dimensional c

11、ontact is given by, which is also tangent to the master surface. The vectors are shown in and . The direction cosines for and n with respect to the global coordinate system are available in dirCosT1 and dirCosN, respectively. In the case of zero incremental slip () we choose an arbitrary direction f

12、or that is orthogonal to the normal direction, n. 為每個接觸點都定義一個局部坐標系以促進摩擦力和增量滑移的規(guī)范。對二維和三維接觸來說，局部1-direction是切向于主接觸面的，并且被定為，其中是增量滑移矢量。增量滑移矢量用來定義相當于在當前時間增量下對罰接觸的增量滑移和對運動學接觸的預測到的增量滑移。主接觸面的法線方向，n，對二維接觸來說是局部2-direction，對三維接觸是局部3-direction。給出了三維接觸的局部2-direction的定義，它也相切于主接觸面。和 給出了矢量圖。的方向余弦和與全局坐標系相關的n分別在dirCo

13、sT1和dirCosN里可行。在0增量滑移的情況下（），我們?yōu)檫x擇一個任意方向，那就是正交于法線方向，n。Figure 1.2.41 Local coordinate system for two-dimensional contact with .Figure 1.2.42 Local coordinate system for three-dimensional contact with .Frictional forcesYou specify the frictional force, fTangential, at each contact point in local coordi

14、nates in this subroutine. The array fTangential is dimensioned such that only the tangential components can be specified. Any components of the frictional force that are not specified will remain equal to zero. For three-dimensional contact with isotropic friction, only the first component of the fr

15、ictional force need be specified since the second component should be zero. A “stick force” at each contact point is provided in the array fStickForce to the assist you in setting appropriate frictional force values. The stick force is the force required to prevent additional “plastic” slipping. The

16、 stick force at each contact point is provided as a scalar value（標量） as it would act in the direction opposite to . The stick force is computed prior to calling user subroutine by either the kinematic or the penalty contact algorithm. See , for descriptions of the kinematic and penalty contact algor

17、ithms and the user interface for choosing between them. The first component of the frictional force should be in the range between zero and minus the stick force value. Typically, the stick force will be positive and the first component of the applied frictional force will be negative, opposing the

18、incremental slip. Penalty contact includes an elastic slip regime due to finite penalty stiffness, so occasionally, during recovery of elastic slip, the stick force will be negative, indicating that it is appropriate for the first component of the frictional force to be positive (i.e., acting in the

19、 same direction as the incremental slip). A noisy or unstable solution is likely to result if the first component of fTangential is set outside of the range between zero and negative the value of the stick force.在子程序的局部坐標系中的每一個接觸點上，你要指定摩擦力，fTangential。ftangential數組被標出，這樣只有切線分量能夠被標明。任何沒有標明的摩擦力分量將仍為0。

20、對三維各向同性的摩擦接觸，只有摩擦力的第一個分量需要被表明出來，既然第二個分量為0。在數組fStickForce每個接觸點上提供了一個“粘附力”來幫助你設定恰當的摩擦力值。該粘附力是避免額外的“塑性”滑移所需要的力。每一個接觸點上的粘附力都是標量，它能夠沿著與相反的方向。該粘附力在調用用戶子程序之前就被或者動態(tài)接觸算法或者罰接觸算法計算出來。See ，After user subroutine is called, frictional forces that oppose the forces specified at the contact points are distributed t

21、o the master nodes. For balanced master-slave contact we then compute weighted averages of the frictional forces for both master-slave orientations. These forces are directly applied if the penalty contact algorithm is being used. If the kinematic contact algorithm is being used, the frictional forc

22、es are converted to acceleration corrections by dividing by the nodal masses.User subroutine interface(用戶子程序界面)subroutine vfric(C Write only - 1 fTangential, C Read/Write - 2 statev,C Read only - 3 kStep, kInc, nContact, nFacNod, nSlvNod, nMstNod, 4 nFricDir, nDir, nStateVar, nProps, nTemp, nPred, n

23、umDefTfv, 5 jSlvUid,jMstUid, jConSlvid, jConMstid, timStep, timGlb, 6 dTimCur, surfInt, surfSlv, surfMst, lContType, 7 dSlipFric, fStickForce, fTangPrev, fNormal, frictionWork, 8 shape, coordSlv, coordMst, dirCosSl, dircosN, props, 9 areaSlv, tempSlv, preDefSlv, tempMst, preDefMst) C include vaba_pa

24、ram.inc'C character*80 surfInt, surfSlv, surfMstC dimension props(nProps), statev(nStateVar,nSlvNod), 1 dSlipFric(nDir,nContact), 2 fTangential(nFricDir,nContact), 3 fTangPrev(nDir,nContact), 4 fStickForce(nContact), areaSlv(nSlvNod), 5 fNormal(nContact), shape(nFacNod,nContact), 6 coordSlv(nDir

25、,nSlvNod), coordMst(nDir,nMstNod), 7 dirCosSl(nDir,nContact), dircosN(nDir,nContact), 8 jSlvUid(nSlvNod), jMstUid(nMstNod), 9 jConSlvid(nContact), jConMstid(nFacNod,nContact) 1 tempSlv(nContact), preDefSlv(nContact,nPred), 2 tempMst(numDefTfv), preDefMst(numDefTfv,nPred) user coding to define fTange

26、ntial and, optionally, statev return endVariable to be definedfTangential(nFricDir, nContact)為摩擦力分量矩陣，不存在摩擦力時，它為零矩陣，一直到人為地更新重設為止；This array must be updated to the current values of the frictional force components for all contact points in the local tangent directions. See and for definition of the l

27、ocal coordinate system. This array will be zero (no friction force) until you reset it.Variable that can be updatedstatev(nstateVar, nSlvNod)：該矩陣包含了從接觸面所有節(jié)點上用戶定義的solution-dependent狀態(tài)變量；This array contains the user-defined solution-dependent state variables for all the nodes on the slave surface. You

28、 define the size of this array (see , for more information). This array will be passed in containing the values of these variables prior to the call to user subroutine . If any of the solution-dependent state variables is being used in conjunction with the friction behavior, it must be updated in th

29、is subroutine. The state variables are available even for slave nodes that are not in contact. This may be useful when, for example, the state variables need to be reset for slave nodes that are not in contact.Variables passed in for informationkStep: 為載荷步； Step number.kInc ：為增量步； Increment number.n

30、Contact：為發(fā)生接觸的從接觸面節(jié)點數； Number of contacting slave nodes.nFacNod：值等于2時主接觸面為二維，等于3時為三維接觸，如果把主接觸面作為剛性面，則其值為零； Number of nodes on each master surface facet (nFacNod is 2 for two-dimensional surfaces, nFacNod is 4 for three-dimensional surfaces). If the master surface is an analytical rigid surface, this

31、 variable is passed in as 0.nSlvNod：為從接觸面節(jié)點數 Number of slave nodes.nMstNod：為主接觸面節(jié)點數； Number of master surface nodes, if the master surface is made up of facets. If the master surface is an analytical rigid surface, this variable is passed in as 0.nFricDir：為接觸點處的切向數； Number of tangent directions at t

32、he contact points (nFricDir = nDir - 1).nDir：為接觸點的參考坐標維數； Number of coordinate directions at the contact points. (In a three-dimensional model nDir will be two if the surfaces in the contact pair are two-dimensional analytical rigid surfaces or are formed by two-dimensional elements.)nStateVar：用戶定義的

33、狀態(tài)變量的數目; Number of user-defined state variables.nProps：摩擦模型需要調用的用戶定義屬性值數目； User-specified number of property values associated with this friction model.nTemp：等于1考慮溫度影響，等于0不考慮溫度的影響； 1 if the temperature is defined and 0 if the temperature is not defined.nPred：為預定義的場變量數； Number of predefined field var

34、iables.numDefTfv： Equal to nContact if the master surface is made up of facets. If the master surface is an analytical rigid surface, this variable is passed in as 1.jSlvUid(nSlvNod)：為用戶定義的從接觸面節(jié)點全局坐標矩陣；This array lists the user-defined global node numbers (or internal node numbers for models defined

35、 in terms of an assembly of part instances) of the nodes on the slave surface.jMstUid(nMstNod)：為用戶定義的主接觸面節(jié)點全局坐標矩陣； This array lists the user-defined global node numbers (or internal node numbers for models defined in terms of an assembly of part instances) of the nodes on the master surface. If the

36、master surface is an analytical rigid surface, this array is passed in as a dummy array.jConSlvid(nContact)：為從接觸面發(fā)生接觸的節(jié)點號矩陣； This array lists the surface node numbers of the slave surface nodes that are in contact.jConMstid(nFacNod, nContact)：為主接觸面發(fā)生接觸的節(jié)點號矩； This array lists the surface node numbers

37、 of the master surface nodes that make up the facet with which each contact point is in contact. If the master surface is an analytical rigid surface, this array is passed in as a dummy array.timStep：為時間步的大?。?Value of step time.timGlb：為所需的總時間； Value of total time.dtimCur：為當前時間增量； Current increment i

38、n time from to .surfInt：為用戶指定的相互作用表面的名稱，向左對齊； User-specified surface interaction name, left justified.surfSlv：為從接觸面的名稱； Slave surface name.surfMst：為主接觸面的名稱； Master surface name.lContType：為接觸類型標志符； Contact type flag. This flag is set based on the type of constraint enforcement method (see ) being use

39、d: 1 for kinematic contact and 2 for penalty contact. Stick conditions are satisfied exactly with the kinematic contact algorithm; they are satisfied only approximately (subject to an automatically chosen penalty stiffness value) with the penalty contact algorithm.dSlipFric(nDir, nContact)：為當前時間增量步下

40、的局部坐標系中每個接觸點的增量摩擦滑動力； This array contains the incremental frictional slip during the current time increment for each contact point in the current local coordinate system. These incremental slips correspond to tangential motion in the time increment from to . For penalty contact this incremental slip

41、 is used to define the local coordinate system at each contact point (see and ) so that only the first component of dSlipFric can be nonzero in the local system. The contact points for kinematic contact are determined based on penetrations detected in the predicted configuration (at ), and the predi

42、cted incremental slip direction is used to define the local coordinate system at each contact point. If the slip direction changes between increments, dSlipFric may have a nonzero component in the local 2-direction and, if the surface is faceted and the contact point moves from one facet to another,

43、 in the local 3-direction.fStickForce(nContact)：為在每個接觸點上執(zhí)行粘著接觸時索要求的摩擦力的大小矩陣； This array contains the magnitude of frictional force required to enforce stick conditions at each contact point. For kinematic contact this force corresponds to no slip; for penalty contact this force depends on the previo

44、us frictional force, the value of the penalty stiffness, and the previous incremental slip. The penalty stiffness is assigned automatically. Occasionally, during recovery of elastic slip associated with the penalty method, the stick force will be assigned a negative value.fTangPrev(nDir, nContact)：為

45、之前載荷步計算出的摩擦力組件值矩陣； This array contains the values of the frictional force components calculated in the previous increment but provided in the current local coordinate system (zero for nodes that were not in contact).fNormal(nContact)：當前時間步的最后接觸點上的正應力的大小矩陣； This array contains the magnitude of the no

46、rmal force for the contact points applied at the end of current time increment; i.e., at time .frictionWork：為分析過程中整個模型的所有摩擦損耗大小； This variable contains the value of the total frictional dissipation in the entire model from the beginning of the analysis. The units are energy per unit area.shape(nFacNod, nContact)：為主接觸面上點的形狀函數矩陣； For each contact point this array contains the shape functions of the nodes of its master surface facet, evaluated at the location of the contact point.