鐵釘整理機(jī)設(shè)計(jì)【三維SW建?！俊?張CAD高清圖紙、文檔所見所得】

【溫馨提示】=【1】設(shè)計(jì)包含CAD圖紙 和 DOC文檔，均可以在線預(yù)覽，所見即所得，dwg后綴的文件為CAD圖，超高清，可編輯，無任何水印，充值下載得到【資源目錄】里展示的所有文件=【2】若題目上備注三維，則表示文件里包含三維源文件，由于三維組成零件數(shù)量較多，為保證預(yù)覽的簡潔性，店家將三維文件夾進(jìn)行了打包。三維預(yù)覽圖，均為店主電腦打開軟件進(jìn)行截圖的，保證能夠打開，下載后解壓即可。=【3】特價(jià)促銷，拼團(tuán)購買，均有不同程度的打折優(yōu)惠，詳情可咨詢QQ：1304139763 或者 414951605= Optimal Design of Compliant Trailing Edge for Shape ChangingAbstract: Adaptive wings have long used smooth morphing technique of compliant leading an d trailing edge to improve their aerodynamic characteristicsThis paper introduces a systematic approach to design compliant structures to carry out required shape changes under distributed pressure loadsIn order to minimize the deviation of the deformed shape from the target shape，this method uses M ATLAB and ANSYS to optimize the distributed compliant mechanisms by way of the ground approach and genetic algorithm (GA)to remove the elements possessive of very low stressesIn the optimization process，man y factors should be considered such as air loads，input displacements，and geometric nonlinearities。Direct search method is used to locally optimize the dimension an d input displacement after the GA optimization。The resultant structure could make its shape change from 0 to 93degreesTheexperimental data of the model confirm s the feasibility of this approachKeywords： adaptive wing；compliant mechanism；genetic algorithm ；topology optimization；distributed pressure load；geometric nonlinearity1 Introduction：As conventional airfoil contours are usually designed with specific lift coefficients and M ach numbers，they could not change in accordance with the environment changingSiclari and Austin indicated that the variable camber trailing edge would produce the drag about sixty percent less than the conventional fixed camber airfoilThere are three methods used to design able camber wingsOf themone is conventional hinged mechanism，which，however, will create discontinuities over the wings surface leading to earlier airflow separation an d drag increase The others are smart material and the compliant mechanism，of which both could realize smooth shape changingNevertheless，compared to the compliant mechanism，the smartmaterialmade actuators have many disadvantages，such as deficient in energy ,slow in response，strong in hysteresis，limited by temperature，and difficult to control too many actuatorsMusolff from Industry University of Berlin used NiTi shapememoryalloy wire to make an adaptive variable camber wing，which could quickly change its shape，but could not perform highly frequent alteration because of its resilience depend en ton the heat exchange with the outside environment。 Compliant mechanism is a kind of one-piece flexible structure，which can transfer motion and power through its own elastic deformationIt is not only flexible enough to deform，but also has enough stiffness to withstand external loadsThanks to its jointfree nature，it does not have the trouble some problems confronted by conventional mechanism such as friction，lubrication，noise and recoiling，thereby achieving smooth shape changing. In 1 994，Kota，a professor from University of Michigan，firstly pointed out that compliant mechanism could be used to control static shape changing under the sponsorship of the Air Force Of ice of Scientific Research in USASaggere and Kotasuggested a new method to design compliant adaptive structures，which made the least square errors between the shapechanged curve and the target curve as the objective function for optimizationBased on their work，Lu put forward a load pathrepresentation methodHowever, her work was limited to only linear analysis under consideration of nodal loadsGood from Virginia Polytechnic Institute of State University used the compliant mechanism and the Moving Asymptotes method to design the fuselage tail within the allowable range of its tip maximal deflectionKota and He trick in2004 designed a compliant trailing edge on the baseof the F16s data，which can change from 0。to 15。and obtained a patentCampanile from German Aerospace Center presented a modal procedure to design synthetic flexible mechanisms for airfoil shape control，and pointed out that the future research should take into account the air load and the geometric nonlinearityBuhl from Riso National Laboratory of the Wind Energy Department in Denmark used the SIM P method and geometrically nonlinear finite element method to design compliant trailing edge flapsFlxSys Inc in 2006 produced an adaptive compliant wing，which stood the test on the White Knight airplaneThe results indicated that the compliant trailing edge could change+10 In China，the research of adaptive wing has been concentrated on smart material and conventional mechanismFew people，it seems，have worked on designing adaptive wings with the compliant mechanismYang is an exceptionHe analyzed the active aeroelastic wings based on the aeroservoelasticity technologyChen and Huang separately investigated the morphing of the compliant leading edge from the viewpoints of discreteness and continuity. This paper presents a method to design the shape changeable structure by MATLAB and ANSYS associated with distributed compliant mechanism on the base of the ground structure approach and genetic algorithm (GA)taking into account the external distributed loads and geometric nonlinearity.2 Optimization Process:21 Defining the trailing edge model and objective function As shown in Fig1，both curves represent two ideal shapes of the trailing edge in the different flying statesOne side point)of the structure is supposed to be fixed，and the other side point) to be sliding horizontally. Firstly, the design domain should be defined by the initial curve shapethe input location and the boundary conditionsThenit is divided with abeam element network simulating the birds feather as shown in Fig2This is termed the partial ground structure method. Fig1 Initial shape and target shape Fig2 Discretization of the design domain The simplest and most effective way to manufacture the planar compliant mechanism is to use wirecutting technologyIn the optimization program，all the elements are of rectangular beams with the same width equal to the thickness of the material，every beams height being a design variableIn order to make the structures deformation come close to the target shape curve，the least square error(LSE)between the deformed curve and the target curve is defined as the objective functionLSE is the sum of squares of position differences of various points along the curves Its expression is where I (=1，2，P)is the number of the points along the curves，P is the total number of pointsandare the coordinates of it h node on the target and deformed boundary curve respectivelyThe constraints are Where J (=1，2， )is the number of elements，miss the tota1 number of elements，hi the dimension variable，hmin and hmax are the lower and upper bounds of the element beam height for all elements with the value dependent on manufacturing，hb the height of the boundary elements， the maximumnoda1 deformation of the nodes on the curve boundary when the input point is inactive，and should be smaller thandto ensure structure stiffness，d the allowable maximum displacement when the input point is inactive，Omax the maximum stress of al1 the elements which must be smaller than Tj to prevent yielding，Tj the topology variable equal to 1，or else0 when the element is eliminated22 GA optimization GA is an optimization method which simulates the heuristic selection rule in nature，where the fittest living things have the most chance to survive，but the inferior ones also have the opportunity to exist Different from the continuous optimization method，it does not require the gradient-based information of the objective function. Every element could be expressed as a topology variable and a dimension variable Therefore，each individua1 could be coded as follows where ，2 is the number of elements except the boundary onesWith the same heights，the boundary elements throughout the optimizing process arerepresented by only one variable，hb.The fitness is the criterion of the GA optimizationIt could be transformed from the objective function into where is a coefficient deciding the compulsive selection of the betterindividua1The smaller the value，the more different would be between the two individualsfitness thus increasing the compulsiveness of choosing the individual of higher fitness The selection of control parameters plays an important role in the convergence of the GAGenerally speakingthe cross probability ranges 040099；the mutation probability is 0000 01-001and the number of individuals 1 0200 The variable would be updated through the crossover and mutation，so the possible design could generate in the GA process23 Finite element analysis(FEA) Because of the limited design variables and the target function，the optimization module of FEA software could not be used to design the compliant morphing mechanismTherefore，this paper programmed the GA in MATLAB and the FEA in ANSYSIn the FEA，taking only account of geometric nonlinearities and the material being of linear elasticity, ANSYS could solve the node displacements and the element stressesThen by deleting the elements with low stress，the fitness could be calculatedFig3 shows the detailed process Fig3 Flowchart of the structural optimization program24 Second optimizationAlthough the GA could optimize the topology and dimension simultaneously in a large solution space，the dimension usually could not directly converge to the optimizationIn order to solve this problem，after the GA，the Direct Search methodshould be used to find the best values of the input displacement and the dimensions of the elements which remain in the results after the GAFor morphing of compliant mechanism，F(xiàn)ig3describes the whole optimization processIt mainly contains initialization of the design domain，F(xiàn)EA，GA optimization and second optimization.3 Presentation of Results:Adopted from Ref，the sizes of the initial and the target trailing edge are reduced by sixty percent，I1ab1e 1 lists the design parameters.Because the displacement is used as the input，the nonlinear analysis could hardly converge and the stress of the initia1 solutions is very largeWhich should be considered after thirtieth generation.Table 1 Design parameters Fig4 and Fig5 illustrate the results from the GA optimization and the second optimization respectivelyFig4 Results after the GA optimization Fig5 Results after the second optimizationForm Table 2，it could be found that through the second optimization of the input displacement and the dimension，the LSE is reduced by 1352 8mmand improved by 313 The altered angle is increased by 1049 3Table 2 Results after the two optimization Fig6 Stability of final optimal structureFig6 shows the influences of the parameters when the outside distributed pressure load changes from 0 to 1 0 Nmm and the input displacement remains 1 1389 7 mm on the optimal structureIt could be seen that the optimal structure has a good stability if the load is kept in the range Of 05 NmmAs the external load exceeds 5 Nmm，the max stress is likely to exceed the yield stressBecause this optimization program is based on the M ATLAB and ANSYSin order to verify the resultsan attempt is made to introduce the analytical results of the optimized structure into ANSYS and PATRAN respectively, and then a comparison is made between themAs shown in Fig7 and Fig8，the two altered shapes are in good agreement：for in ANSYS the tip displacement is 5497mm and in PATRRAN 5450mmThe minor difference between them is from the software Fig7 Results of FEA in ANSYS Fig8 Results of FEA in PATRANOn the other hand，a model is made by wirecutting technology to verify the analytical resultsThe material of the mode1identical with that of the design，is 5 mm thickIn the experiment，the distributed pressure load is assumed to be zeroThe input displacement 11389 7mm with the required input load 146 NFig9 shows the model and the experimental resultThe altered angle is measured93。and the tip displacement 53mmThe altered shape well accords to the optimized resultIf a displacement of 113897mm is imposed on the model，the theoretical tip displacement is 54796 mm Because of the friction there is between the model and the experiment table a tiny difference will take place between the measured data and the calculated resultsFig9 The model and experimental result 4 Conclusions：Proved by the simulation and experiments，the proposed method to design morphing compliant mechanism is effectual in turning out a trailing edge with required morphing effects and ability of withstanding external loadsThe combination of MATLAB and ANSYS in the optimization renders the program simple and universa1There is no need for frequent changes of the rigid matrixIt also avoids the complexity of programming the nonlinear FEA and the transforming distributed loads into nodal loadsUsing the mixed code，the topology and the dimension could simultaneously be optimized by the GARemoving the free elements after the FEA could speed up the optimizationThe second optimization could improve the GA results 20