DYNAFORM studies in the application in strike out form
- source:YESCOM CNC Machining
Ind and Material.
Two files comprise Lib. Material.
Ind included all protecting to be put in the material name in the library and list. After user first time exports material information, two afore-mentioned files are automatic generate below the root catalog of user computer. In the analysis later, should read in relevant data only can. Imitate of numerical value of 1 drawing figuration to drawing, the obstruction of going from place to place to the makings in drawing figuration has the preform appearance, power that approach a limit very big impact, similar work, because preform geometry figure is different, measurement of the force that approach a limit is different, the stress condition that produces when figuration has very big distinction. So, how to optimize the appearance of preform, tone conformity presses Bian Lixian just to must be attached most importance to especially should. My workshop produces some model the drawing figuration of regulation of dispute of engine rear wall, if pursue,1 is shown. Rear wall uses ply to be the 1Cr18Ni9Ti material of 1mm, in laminose figuration craft, the drawing that it belongs to blame regulation. From the graph 1 can see, this spare parts appears easily in figuration decrease thin (the graph is shown 2 times) and rupture (CRACK) phenomenon (the graph is shown 1 times) . Measure so that what data performance data shows as follows through the experiment: (1) model of raise family name measures E=184MPa; (2) Poisson compares μ =0.
3; (3) succumb stress σ =540MPa; (4) =0 of sclerotic index η .
186; (5) board thick 1mm; (6) anisotropy coefficient R=0.
7; (7) the F=0 of coefficient of friction between punch-die and plank.
15, press the F=0 of coefficient of friction between frontier group and plank.
1. Mould component and the geometrical model of board makings are founded in UG, read in by the IGES interface of DYNAFORM, undertake pre-treatment. Rear wall spare parts imitate of its numerical value is finite yuan of unit of the model number is 2341, node number is 2183, the unit of material of its medium plate number is 1578, node number is 1676. Graph 1, graph the 2 figuration limit cloud atlas before be being optimized for board makings respectively and ply change cloud atlas (FLD) ; Graph 3, graph 4 it is figuration limit cloud atlas and the ply change after board makings is optimized respectively cloud atlas. Nextpage can know from imitate result, before board makings appearance is optimized, as a result of data of conic drawing share flow is out of shape obstruction is lesser, and body part ministry receives makings instruction bigger, press figuration principle of the least resistance, body part ministry board makings flow is out of shape less, bring about bottom circle horn to be in craze, the place ply attenuates amount to 80% , look from FLD curve, this area has faced boundary line more than, although press edge force to fall to 16T, imitate result change is not big. After board makings appearance is optimized, the board makings dimension of conic drawing part is increased appropriately, receive makings instruction in order to balance body part ministry, the force that approach a limit is given for 26T, look from imitate result, ply of part of round part of box form floor attenuates for 25% , look from FLD curve, this area is in critical line inside. Imitate of numerical value of figuration of 2 multitask foreword is in plank punch figuration, multitask pace take shape is a kind of more commonly used technology. And in numeric imitate, if where manages,the key is last time the plank stress that figuration earning goes to and information of meet an emergency, in making plank stress and information of meet an emergency include the model in the 2nd figuration. In the numeric imitate of take shape of situation of the first labor, when output parses a document, open multitask foreword to machine (DANAIN) switch, such, after finishing imitate of numerical value of take shape of situation of the first labor to calculate, included DANAIN file in computational result file. Plank included to get the information such as the stress that arrive and meet an emergency in the place in first time figuration in DANAIN file; Doing next next when figuration is analysed, input interface to read in DANAIN file through multitask pace take shape. Graph 5 it is me after company core paragraph the imitate result of numerical value of two drawing figuration. Imitate of numerical value of figuration of Nextpage3 canal material is inside domain of strike out form the research that curves figuration to providing material is less, have pair of round pipe fitting only bend it is certain to have discuss, in the canal consequently material curves figuration respect to do not have relatively mature theory and experience algorithm. Trend of figuration spring back is reached to cannot be made to the form of going from place to place of makings when be in charge of material to curve figuration foreknow well and truly. The maturity of numeric imitate technology and the research that use the material that it is a canal to curve figuration offerred credible solution. My workshop gained successful experience in respect of imitate of numerical value of figuration tubal material, if the graph is shown 6 times,be result of imitate of figuration of some engine fuel feed pump, preform is external diameter φ the hollow circle of 20 is in charge of, the wall is large for 0.
8mm, material is 0Cr18Ni9 steel. 4 curve imitate of figuration numerical value to be in aviation manufacturing industry, the circular arc of laminose makings curves figuration under 2mm of board makings ply relatively common. Because radius of bend is big (opposite at board makings ply) , in the inevitably meeting when bending occurrence flexibility is out of shape, the angle of bend that causes work is spent and circular arc radius has accurate control very hard. DYNAFORM has the function that analyses spring back, spring back is opened to analyse switch when wanting to analysing a file to output only (Spring Back) can undertake an analysis. Those who want a specification is, the element that curves spring back as a result of the influence is daedal, numeric imitate result remains in the accuracy of mensurable respect at farther test and verify, but the indication in the graph makes clear, numeric imitate result is in the dependability of directional respect is beyond question. When making simulation of spring back numerical value with DYNAFORM, can use correction data performance data and the way that change attrib border condition to plan to close with actual result. DYNAFORM applies common problem and processing method to be when the application of DYNAFORM, the problem that its often encounter and processing method are shown as follows: (1) when doing spring back to analyse, seek solution not convergent. The following method can use at rising astringent: A: Use more load ministry. Give by the Nstepsb parameter of Control_implicit_general key word. B: Adjust the parameter SCALE of Control_implicit_STABILIEATION, if pace of the first load is not convergent, choose greater numerical value namely; When if be close to,ending not convergent, choose lesser numerical value; If return not convergent, can increase load pace. C: Adjust the Lstol parameter of 4Control_implicit_nonlinear key word, lesser number selects below most circumstance. (2) there are a lot of contact types to offer user alternative in LSDYNA, in board which sort does figuration analysis middling use model? Emulate in punch in, commonly used contact is special at board the FORMING of figuration kind contact. In this kind of contact, take no account of the ply of the mould, reduced the successional demand to mould reseau at the same time. Use two kinds of following types normally: One kind is CONTACT_FORMING_ONE_WAY_SURFACE_TO_SURFACE, this kind of type is the most commonly used. One kind is CONTACT_FORMING_ SURFACE_TO_SURFACE, this kind should use more time. When using the first kind of means, if the reseau of the mould is even closer than the reseau of board makings, often appear bigger contact is penetrable, can use type of this kind of contact right now. (3) when should doing drawing to analyse, appear apparent contact is penetrable, how to undertake controlling? Can try the following kinds of way: A: Increase the SLSFAC parameter in CONTROL_CONTACT key word, this parameter limits is in normally 0.
1 with 0.
01 between, as a result of stability reason, do not exceed 0 commonly.
1. B: Choose other osculatory types. If the reseau of the mould is closer than board makings reseau, the proposal uses CONTACT_FORMING_SURFACE_TO_SURFACE. C: Use Constrarint contacts a type, namely CONTACT_FORMING_ONE_WAY_SURFACE_TO_SURFACE, increase Optionial CardA, its parameter SOFT=4 can. (4) the algorithm that there are a lot of housing units in LS_DYNA, figuration of what comfortable plywood is analysed? If just undertake drawing is analysed, choice BT carapace is unit (Element#2) , rate is very rapid, the result can be accepted; If want to undertake spring back is analysed after drawing, choose unit of completely integral housing (Element#16) , advantage is to be able to achieve better spring back outcome and convergent result, defect is to expend time to grow. The last word analyses a technology to study in the application in punch technology domain through numeric imitate, the experience that changed my company tradition is added solid the punch that does an experiment to give priority to machines mode. Technology of numeric imitate analysis reachs what the mould designs to forecast to punch craft reach direct action to make punch craft had foresight and scientific sex, also raised the accuracy that the mould designs and dependability. Of technical measure rise, shortened substantially mould design and make debugged cycle, also promoted the suiting that the company competes to the market capability. Technology of imitate of applied numerical value can forecast a figuration course that gives a part successfully, but the figuration process that with imitate the analysis replaces a tradition still has a lot of jobs to want to do. The research of technology of imitate of numerical value of plank figuration sex should consider the idea of systematic project, the control that because want,involves process of design of material, mould, figuration, sanction that adjusts drawing muscle and generation of the circle that approach a limit, lubricant wait for many sided element. Want to raise the level of technology of imitate of numerical value of figuration of our country plank, introducing, below the premise that absorbs foreign new and high technology, still need the communication of much discipline and cooperation, include technology of science of craft of mould design, punch, numeric method, mechanical, material, computer to wait among them, so that make this one new and high technology can solve more real industry to produce a problem, bring bigger economic benefits at the same time. CNC Milling CNC Machining