Finite yuan of technology application in treatment of aviation whole structural member

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The wide application of integral structural member improved the integral performance such as plane, spacecraft significantly. However aviation whole structural member mostly the structure is complex, size is larger, appearance precision demand is high, material purify amount is large, treatment cycle is long, treatment quality and precision are controlled hard, once appear quality problem, not only can cause significant pecuniary loss, and can serious effect produces cycle, the development of the batch production that affects military plan and new model [1] . Traditional research and the problem that solve treatment of high speed of aviation whole structural member, efficient, high accuracy basically depend on experience or experiment, efficiency is low and of experimental data but sex of put sb in a very important position is poor. Mix as computer technology finite yuan of technical development, finite to machining the crucial link of the process to undertake yuan emulation computation becomes a possibility. Since Wienkiewicz and Kakino were built above all 1971 cut bits to form finite yuan since the model [2] , through development of nearly 40 years, finite yuan of technology already was forecasted with flow at cutting bits to form by wide application, cutting tool structure optimizes parameter of design, craft and of aviation whole structural member be out of shape forecast, control and corrective the research that waits for relevant domain, concerned research is used successfully already at directive production as a result. The structural member of helicopter titanium alloy that Sikorsky company produces yoke S-92 is initiative the treatment method that uses a convention, need a lot of equipment and very long handling time. Produce efficiency and economic benefits to rise, this company and Third Wave company cooperate, use finite yuan of software AdvantEdge imitate the treatment process of this spare parts, optimize cutting to machine parameter, improved workpiece quality thereby, prolonged cutting tool life, reduced work loss [3] . Finite main show is in yuan of outstanding advantage that emulation technology machines medium applying in aviation whole structural member as follows a few respects: (1) announce the physics with a lot of unavailable experiments is mechanical phenomenon, the treatment process parameter that obtains an experiment to check hard (rate of the temperature that is like cutting area, meet an emergency, stress, meet an emergency) , temperature of force of the flow cutting bits that falls to different cutting condition, cutting, cutting tool and stress undertake forecasting, for aviation material high speed mechanism of efficient treatment cutting considers to provide support; (2) reduce an experiment to study workload greatly, reduce research investment, shorten research and development is periodic; (3) can undertake emulation an analysis to the main treatment process of whole workpiece, be out of shape to treatment undertake forecasting, parameter of plan of implementation outfit mix, craft optimize. The article will join task group in recent years research works, around finite yuan emulate domain of the crucial technology that in aviation whole structural member the application in making involves, application and development trend to undertake an analysis. The in building 1 cutting of 　 to machine emulation analysis material model material of this compose relation model is in the material below cutting condition the accurate description of mechanical behavior below requirement of ratio of high temperature, great strain, tall meet an emergency, namely material of this compose relation model building is the foundation that comes true to machine a process to be forecasted effectively to workpiece cutting and premise [4] . Current, the material model that depicts material conduct character can divide it is 2 kinds: Microstructure model (Microstructural Models) and stream change learn a model (Rheological Models) [5] . (The act that 1) microstructure model uses microstructure parameter description to be out of shape the process counteracts the material after be out of shape is characteristic (include sclerotic, dynamic reply, dynamic recrystallization to wait) , already had model of ten kinds of dynamic structures, if cutting treatment is medium,wait with the Zerrilli-Armstrong model that arrive. They all are a foundation with the experiment, to material function calculate a function stronger, but extrapolate precision is inferior, the experimental workload that needs to undertake to win model parameter place is big, time and fund expenses are taller. These elements bring about microstructure model to process the application in emulation analysis in cutting not quite extensive [5] . (2) stream change the model is divided again analyse model and model of experience assuming analyse for physical model, experience. The model mirrorred physics to be out of shape phenomenon of the physics in the process (include arrive from atomic span the measure limits of successive body) , model parameter needs to expend many time and charge certainly, this kinds of model is in finite yuan of emulation analysis is medium be applied very hard. Model of experience assuming analyse basically is based on nerve network model, do not need this transcendental compose law and the description to phenomenon of complex and microcosmic organization. Experience analysis model is macroscopical scale model (or call successive body the model) , plan to add up to experience formula to obtain through experimental parameter, do not mirror be out of shape the physical phenomenon in the process, can well the curve of stress meet an emergency that be identical experiment obtains. Experience analysis model was experienced by arrive simply to evolve complexly, the material that already can depict material to lead a condition to fall in high temperature, great strain, tall meet an emergency well now is mechanical behavior, it is current cutting treatment is finite the model of a kind of material with yuan of the widest application in emulation analysis, like Johnson-Cook(JC) material this compose concerns model. JC model was put forward 1983 by Johnson and Cook, it is descriptive material the phenomenological model of mechanical below condition of rate of great strain, tall meet an emergency, high temperature behavior, the aggrandizement of meet an emergency that reflected data adequately, meet an emergency leads aggrandizement and temperature bate effect. As a result of JC model the model parameter of all sorts of simple, material is obtained easily, make this model is emulated in cutting in win wide application. Be aimed at different material and specific application characteristic, a lot of investigator undertook improvement to JC model. The acquisition of parameter of model of 2 tests data takes no account of material micromechanism, of the material model parameter that mirrors material integratedly to leave mechanical action in condition of rate of different meet an emergency, meet an emergency, temperature get a method to basically include: Method of simple stuff experiment; Cutting (Orthogonal Cutting, OC) experimental law; Material experiment and cutting experiment synthetic method. (1) method of simple stuff experiment. Detached type suddenly Pu Jinsen approachs lever experiment is the material below research cutting condition the simple test method with mechanical the most significant action, this experiment unit founded 1914 by Hopkinson father and son, obtained tall meet an emergency to lead next load first - time-speed-distance curve [6] . 1949, kolsky undertook improvement to this device, become the branch that control lever 2 cut, development controls lever into detached type Hopkinson (Split Hopkinson Pressure Bar, SHPB) , the curve of stress meet an emergency that makes this one device can be used at measuring material to fall in concussion load thereby [the dynamic and mechanical behavior of the material below rate of tall meet an emergency of 7] , research. This technology reachs his corresponding equipment gets ceaseless development, at present SHPB can realize great strain (0.

5) , tall meet an emergency is led (104s-1) with high temperature (1100 ℃ ) the stress of going from place to place below is measured. Nevertheless, SHPB experiment and true cutting condition still are put in certain difference, should give when SHPB experiment data processing consideration. Compare with photograph of actual cutting condition, the main problem that SHPB experiment exists includes [8] : · SHPB experiment heats mediumly the anneal that the process can cause material, and this won't appear commonly in cutting process; The experimental temperature test of · SHPB has certain difficulty, heat in cutty inside time make the temperature of departmental cent achieves sample to agree equably very hard also; · flow stress, exist to fluctuate certainly when low meet an emergency is worth especially; · cannot be used commonly in the numerical value inside stretch limits, need undertakes the experiment decides additionally; Concussion of · high speed is put in inertial effect; · meet an emergency, meet an emergency leads the numeric on the low side that plays than true cutting condition. Nextpage 　 　 (2) cutting experiment law. Cutting experiment law is the cutting theory with Oxley is a foundation, use orthogonal cutting test, through measuring stress of flow of cutting force estimation and meet an emergency, at the same time combinative cutting speedometer calculates rate of meet an emergency and temperature. The stress of going from place to place that rate of attainable different meet an emergency, meet an emergency, temperature lays test of many groups of orthogonal cutting, plan to combine this compose model of a material thereby. Material of rate of the great strain that cutting experiment law can obtain SHPB to cannot be achieved, tall meet an emergency, high temperature is characteristic. American Ohio city establishs university clean figuration to make the T of engineering center.

Professor Altan did outstanding work in this domain, the engineering center that he is in put forward to be based on theory of Oxley parallel skid wire, through begging stress of going from place to place instead invariable methodological compose establishs the method of equation of data flow stress, weave corresponding subprogram OXCUT. The main problem that parameter of model of data of orthogonal cutting test fixes to the method exists and the main factor that produce an error include: This compose equation that · obtains through this method suits great strain, high temperature, tall meet an emergency to lead a condition only; · the first regular form that is out of shape area appearance is not Oxley place to assume; Rate of · meet an emergency is in the first be out of shape wave motion exists inside the area. (3) the affirmatory method of comprehensive data experiment and parameter of model of cutting test data. To produce the advantage of SHPB and orthogonal cutting experiment adequately, overcome the inadequacy of respective existence, guo[9] put forward to use SHPB test data and orthogonal cutting experiment integratedly to define material the method of this compose relation model, choose Johnson-Cook material this compose relation model undertakes parameter plans to close. Its are main the practice is: The computation that will be based on cutting experiment to obtain cuts meet an emergency, cut rate of meet an emergency and shearing stress of going from place to place to reach Mises to succumb suppose according to isotropy criterion changeover is equivalent meet an emergency, equivalent meet an emergency rate and equivalent flow stress, pass relevant computation next, the C parameter in making be based on the JC model of SHPB test data and data of orthogonal cutting test is relevant couplet, obtain the material model parameter of character of the material below condition of cutting of can very good report finally. Be based on finite yuan cutting tool wears away emulation analysis cutting tool wears away character and rule will produce main effect to workpiece surface quality, finished cost, quantity of excision of metal of aviation whole structural member machines stuff place greatly, hard to hold proportion tall, because this raised very tall requirement to cutting tool. Domestic and international scholar wears away to the cutting tool in process of different material treatment the rule began much research work, however majority studies the job is to be based on experience or experiment [10] . In recent years, finite yuan the technology wears away in cutting tool application is won in research. Use finite tatty of implementation cutting tool forecasts yuan of emulation technology reliably is the new challenge that academia studies to the domain is faced with in cutting tool, the research technique that the high cost that the cutting tool life that this studies to will change a tradition thoroughly studies to rely on experience and experiment completely, high time uses up. Of cutting tool wear away (crescent moon is formed depression with hind knife face wears away) with stress of the cutting temperature in machining a process, contact, knife - bits and knife - labour closely related sliding velocity. Use finite yuan the technology undertakes cutting tool wears away analysis, should build the cutting tool that makes by afore-mentioned ginseng numerical control to wear away above all model, undertake emulation to these craft parameter [11] . Cutting tool wears away emulation flow. Cutting tool wears away forecast an analysis to be able to divide for 4 measure: (1) the consideration is hot - process of cutting of force coupling action emulates an analysis. Realize cutting of successive stable state, accurate forecast the flow that cut bits and the appearance that cut bits. (2) cutting tool conducts heat analysis. Want to achieve the thermal stability of cutting tool, need longer cutting to emulate time, satisfy a requirement very hard with current computer level, yung-Chang[12] put forward pure cutting tool of a kind of computation to heat up conductive approximate method, satisfied emulation requirement. (3) cutting tool wears away rate computation. Choose appropriate cutting tool to wear away the model has corresponding consideration, the cutting tool that Takeyama and Murata[13] put forward wears away the model can consider integratedly to attrition wears away and diffuse tatty influence, wear away in cutting tool finite yuan of application in emulating is wider. (4) appearance of geometry of the cutting tool after wearing away is updated. Basis cutting tool wears away rate is relevant data, wear away by cutting tool face of the knife before the new cutting tool that cause, hind appearance of knife face geometry needs recount, input a file as calculative of next loop pace with this. One is finished to wear away namely after completing these 4 step emulation loop, obtain wear extent of a cutting tool to emulate data. Cutting tool wears away emulation research just still starts, still much work remains to consider, basically include: (1) cutting tool wears away the further development that the model studies; (2) of appearance of the cutting tool after cutting tool wears away reframe speed and the development that precision studies; (3) knife - bits, knife - the development that is versed in osculatory attrition model studies. CNC Machining of structural member of whole of Nextpage 　 aviation is out of shape forecast pass treatment of pair of aviation structural member to be out of shape with control the analysis that produces an account is knowable, semifinished product is initiative and leftover stress is to cause a spare parts to machine metabolic main factor, besides the element such as order of cutting force, heat in metal cutting, cutting, method taking a knife and outfit clip is out of shape to the treatment of the spare parts also have main effect. Use finite yuan of emulation technology is OK undertake integration analysis to afore-mentioned elements, those who realize aviation whole structural member be out of shape forecast with control. Treatment of structural member of 1 aviation whole is out of shape finite yuan of emulation analysis 　 (1) milling is finite of yuan of emulation geometry model build. The treatment of aviation whole structural member is milling treatment mostly. In milling treatment, because do whirligig and feed exercise at the same time, make the athletic contrail of cutting tool is cycloid, form the cut that is similar to sector. Among them Ae is cut for radial deep, ap is cut for axial deep, vf is cutting speed, fz is every tine feed. As a result of the existence of dip of blade of milling cutting tool, cutting blade hands in a line to become proper point of view with what workpiece machines the surface, these elements brought huge difficulty to the imitate that machines a process. Machine the imitate of the process to realize milling successfully, the cut in be being machined to milling undertook simplifying appropriately. Be opposite in cutting tool the cutting load of workpiece will as the whirl of cutting tool with curve form ordinal action is on face Bcfe and cut underside Cdf, after cut appearance simplifies to wait for ply cut, bcfe of face of to load of circular arc form is replaced by rectangular face Bcgh and Efgh, circular arc form cuts bits underside Cdf to be replaced by rectangular face Cdfg, criterion action will turn into in load of arc on-line cutting action is on broken line. Uninstall outfit clip and spare parts freedom to be out of shape for imitate process, in the computer according to 4 phase -- treatment of tie, milling, uninstall and restrain changeover to undertake emulation an analysis [14] . (2) analyse of emulation reseau of process of treatment of integral structural member distributes technical research. Size of integral structural member is large, cut and work measure photograph are compared very small, what should come true to machine a process to structural member of real measure whole is finite yuan of emulation analysis, reseau amount is very huge, computation cannot on the rails. What the university developed Zhejiang to machine a process to emulate an analysis in the light of aviation whole structural member is finite yuan of relay computation system, its core idea is with large and finite yuan of software package ABAQUS seek solution for core implement, to the integral structural member that comprises by feature of look of many small circle, the unit will is with every casing when imitate. The treatment knife according to the spare parts orbit source file, lie between casing to undertake reseau analyse is divided to the first, be far from reseau of this casing area to coarsen gradually, build the reseau model that accords with a requirement; Use border bound condition and cutting load next, make the model file that includes node and unit definition (INP file) , start finite yuan seek solution implement to cutting treatment process undertakes emulation computation. After computation of the first casing is finished, undertake to the 2nd casing reseau analyse is divided again, generate the reseau that accords with a requirement, and be far from reseau of this casing area to become rare gradually, apply border bound condition and cutting load to arrive on corresponding node, make the computational file that includes node and unit definition again, start finite yuan seek solution implement, finite yuan seek solution implement the emulation computation that calculative of the first casing map of interpolation of field volume data regards add of initiative condition succeed as to undertake cutting machines a process to the 2nd casing, such loop machines imitate till what complete whole part. Relay gets used to hexahedral reseau oneself in computational system [15] . 2 finite yuan of application clamping force in installing mix plan to optimize research it is metabolic of structural member of influence aviation whole one of main factors, through adjusting clamping apparatus the position of component or add essential clamping apparatus element, can achieve reduce metabolic goal [16] . Rise as what machine precision requirement to aviation whole structural member, to fitting mix plan actor choosing considers to be taken seriously gradually. Finite yuan of technology main effect had in installing mix plan to optimize. In recent years, use finite computational method began yuan of numerical value to install clip order, clamp to nod the relevant research such as layout, place of hand-in-hand luggage clip is optimized [17-19] , aviation whole structural member because its structure characteristic, decided its hold clip the part is very much, often have a few, get on 100 even. Machine the as material purify in the process, workpiece becomes weak rigid part gradually by rigid spare parts, the strategy that hold clip must satisfy aviation whole structural member to machine characteristic of this one change in the process. Task group was begun in order to machine casing of the aviation in the process kind of integral structural member the biggest be out of shape the smallest for target function, use heredity algorithm and finite the method of yuan of law photograph union, built aviation frame kind position of spot of clamp of integral structural member and recurrence of eye of clamp check the number optimize a model. Optimize a model to undertake to aviation whole structural member layout is optimized holding clip according to this, undertook an analysis to the contact of clamping unit and attrition problem at the same time, to hold clip plan is optimized finite yuan those who analyse condition of the border that build a model is affirmatory provide a basis. Undertake through using genetic algorithm to lying between casing spare parts place is optimized holding clip, treatment is out of shape ratio before optimizing, decreased 14.

2% , outside position of position of stage of side clamp protruding optimizes convergent process. The CNC Machining of integral structural member is out of shape corrective technology studies to a lot of aviation whole structural member, although adopt advanced manufacturing technology and optimized craft parameter, the influence of all sorts of complex elements in the treatment of aviation whole structural member that mentions as a result of preamble place, CNC Machining is out of shape also unavoidable, short-term inside the treatment of structural member of very difficult still will all whole is controlled completely it is in design precision limits, can say to be out of shape school the important step that makes sure production precision of aviation whole structural member is indispensable just about [20] . Finite yuan numeric computation is out of shape main effect is produced in the middle of school in aviation whole structural member, corrective to be out of shape instead, pass finite yuan of numeric computation, can accurate computation is corrective parameter, will be out of shape corrective build go up in scientific computation foundation, the change is traditional the extensive by experience be out of shape corrective production means. To Bao Bi structural member put forward to be based on boil press stress redistribution to be out of shape corrective theory and method. Material of the semifinished product in research employs 7050-T7451 aluminium alloy beforehand drawing plank, its in-house leftover stress distributings have certain regularity, be in namely board thick inside same plane, its stress distributings can consider as plane of the 2 dimension inside the face stress condition, there is shearing stress between layer and layer. Use finite the purify process of material of yuan of imitate of technology of unit of life and death, workpiece over all dimension is 40mm of × of 408mm × 120mm, each sidewall is thick for 4mm, workpiece underside is thick for 2mm. Use likewise nonlinear the business with the stronger function that seek solution is finite yuan of analytic software ABAQUS press a process to undertake emulation an analysis to boiling, the displacement of edge X direction, whirl that winds Y way is divided in emulation process, the others freedom is spent all restrain. Roll what 400N uses when pressing to tighten force beforehand, of corrective gyro wheel boil press positional H for 4.

3mm. Use this to boil press parameter to undertake boiling pressing corrective, chan Duan boils press and two end boil press around workpiece to be out of shape comparative. Can see, boil press the corrective effect with was obtained better. Roll deflection of remains of the underside after pressing for 6.

86 × 10-3mm, relatively initiative be out of shape, eliminated the deflection of 90% . Still undertook the experiment is designed additionally, test and verify the validity that offers corrective theory and means. Estimation of domestic and international logarithm calculates conclusion to give height to take seriously in the application in engineering science, the United States built model and the influence that emulate pair of United States projects and scientific progress to form special subject report with respect to the computer 2006. Finite yuan numeric computation makes medium application just start in aviation whole structural member, much science and engineering issue remain to study the application in producing actually with making its further: (1) of database of material property basis and library of material model parameter build remain to strengthen. Left parameter of accurate data model, treatment process is emulated will not undertake. Our country is in of research of data base data and library of material model parameter build still cannot satisfy finite the need of yuan of emulation analysis, especially the aviation data of new emerge in large numbers is more such, this respect and foreign difference are bigger. (2) the knife that need studies to reflect cutting condition further - bits, knife - labour contacts attrition model, in order to raise cutting treatment is finite yuan of emulation analysis precision. (3) cutting tool wears away of the model build still need to begin many theory to study the work, with real report cutting tool wear away characteristic, forecast for cutting tool life provide support, this also is sure to consider to provide new efficient research measure for cutting tool life. (4) aviation whole structural member is out of shape forecast the form that involves semifinished product to digitlize leftover stress field to build, the plan that hold clip is optimized, the respect such as method taking a knife and craft order, every link needs to undertake thorough theory and numeric model build research. (5) should develop be out of shape in the light of aviation whole structural member forecast what optimize with technology strategy to specialization finite system of yuan of emulation analysis software, the working abroad of this respect just just starts, our country also answer integrated each field force, the aviation whole structural member that uses up early development to have own intellectual property is out of shape forecast optimize software system with craft parameter. CNC Milling