【摘要】：由于環(huán)境污染和資源枯竭的問(wèn)題日益加重,在汽車領(lǐng)域進(jìn)行輕量化研究成為了汽車開發(fā)的重要課題。本文通過(guò)對(duì)某款皮卡車型的車門結(jié)構(gòu)進(jìn)行布置和設(shè)計(jì),以此車門為研究對(duì)象建立車門扭轉(zhuǎn)剛度、下垂剛度、側(cè)向彎曲剛度、模態(tài)頻率和抗凹性的有限元模型,并對(duì)車門的各項(xiàng)性能進(jìn)行分析與評(píng)價(jià)。根據(jù)車門結(jié)構(gòu)的輕量化需求,對(duì)車門進(jìn)行多目標(biāo)優(yōu)化設(shè)計(jì)研究,且考慮到不確定因素的干擾,在多目標(biāo)優(yōu)化的基礎(chǔ)上進(jìn)行穩(wěn)健性的檢驗(yàn)與分析,使車門不僅達(dá)到輕量化目標(biāo),還具備良好的穩(wěn)健性,具體研究工作與成果如下:(1)在車門的布置階段,通過(guò)車門中各個(gè)主斷面圖來(lái)完成車門鉸鏈、玻璃升降器、限位器、鎖體、內(nèi)外手柄和防撞梁的布置。在車門的設(shè)計(jì)階段,根據(jù)車門的布置內(nèi)容,對(duì)車門內(nèi)各個(gè)零件進(jìn)行設(shè)計(jì),其中包括對(duì)叉臂式玻璃升降器的平順性、玻璃升降器電機(jī)的快速選型、限位器主臂形狀和密封條進(jìn)行深入研究。在車門完成布置和設(shè)計(jì)后,利用CATIA的DMU模塊,并根據(jù)車門實(shí)際運(yùn)動(dòng)狀況和約束自由度的分析建立車門運(yùn)動(dòng)仿真機(jī)構(gòu),檢測(cè)關(guān)鍵零件之間的最小運(yùn)動(dòng)間隙,以保證車門布置和設(shè)計(jì)的合理性。(2)將車門模型導(dǎo)入HyperMesh中進(jìn)行幾何清理和網(wǎng)格劃分,在檢查和控制車門網(wǎng)格質(zhì)量以后,按照焊接、螺栓和涂膠的連接方式,將各個(gè)零件的有限元模型進(jìn)行連接,并定義結(jié)構(gòu)件的材料屬性,建立車門扭轉(zhuǎn)剛度、下垂剛度、側(cè)向彎曲剛度、模態(tài)頻率和抗凹性有限元模型。在車門有限元模型的基礎(chǔ)上,運(yùn)用Optistruct計(jì)算車門各項(xiàng)性能的仿真數(shù)值,并將其與企業(yè)標(biāo)準(zhǔn)相對(duì)比,各項(xiàng)性能都符合設(shè)計(jì)要求,但仍然存在較大的輕量化空間。(3)首先,根據(jù)車門有限元分析結(jié)果和參數(shù)試驗(yàn)設(shè)計(jì),篩選出貢獻(xiàn)量較大的8個(gè)設(shè)計(jì)變量進(jìn)行設(shè)計(jì)樣本的采樣。其次,以采樣數(shù)據(jù)和響應(yīng)面近似模型原理為依據(jù),構(gòu)建車門質(zhì)量、剛度、抗凹性和模態(tài)響應(yīng)面近似模型,并檢驗(yàn)近似模型的精度。最后,以篩選的車門零件為設(shè)計(jì)變量,以車門扭轉(zhuǎn)剛度、下垂剛度、側(cè)向彎曲剛度和抗凹性滿足要求為約束條件,以車門質(zhì)量最小和車門前三階模態(tài)頻率最大為目標(biāo)函數(shù),構(gòu)建車門多目標(biāo)優(yōu)化的近似模型,并利用NSGA-Ⅱ遺傳算法進(jìn)行求解,獲得車門質(zhì)量與第一階模態(tài)頻率的Pareto非劣解的解集,從中挑選出滿足優(yōu)化條件的最優(yōu)解。優(yōu)化后的車門性能不僅滿足企業(yè)標(biāo)準(zhǔn),還實(shí)現(xiàn)了第一階模態(tài)頻率提高和車門輕量化的目標(biāo),其中車門的質(zhì)量為17.19kg,減輕了0.97kg,減輕的幅度達(dá)到5.34%,而車門第一階模態(tài)頻率為34.59Hz,提高了0.27Hz。通過(guò)蒙特卡洛模擬中的描述性抽樣技術(shù)對(duì)多目標(biāo)優(yōu)化后的車門質(zhì)量水平和可靠度進(jìn)行分析,獲得各個(gè)輸出響應(yīng)的Sigma質(zhì)量水平和可靠度分別為8Sigma和1,則此多目標(biāo)優(yōu)化后的車門已經(jīng)具備良好的穩(wěn)健性,無(wú)需進(jìn)行6Sigma穩(wěn)健性優(yōu)化。
[Abstract]:Due to the increasingly serious problems of environmental pollution and resource depletion, lightweight research in the automotive field has become an important subject of automobile development. In this paper, the structure of a pickup car door is arranged and designed, and the finite element models of the torsional stiffness, drooping stiffness, lateral bending stiffness, modal frequency and concave resistance of the door are established. The performance of the door is analyzed and evaluated. According to the lightweight demand of the door structure, the multi-objective optimization design of the door is studied. Considering the disturbance of the uncertain factors, the robustness of the door is tested and analyzed on the basis of the multi-objective optimization, so that the door can not only achieve the goal of lightweight. Also has good robustness, the specific research work and achievements are as follows: (1) in the door layout stage, through each main section diagram of the door to complete the door hinge, glass elevator, position limiter, lock body. Layout of inner and outer handles and anti-collision beams. In the design phase of the door, according to the layout of the door, the various parts of the door are designed, including the smoothness of the fork-arm glass elevator and the quick selection of the glass elevator motor. The shape of the main arm of the limiter and the sealing strip are studied in depth. After the car door is arranged and designed, the DMU module of CATIA is used, and the simulation mechanism of the door motion is established according to the analysis of the actual motion condition and the constraint degree of freedom of the door, and the minimum motion gap between the key parts is detected. To ensure the rationality of the car door layout and design. (2) introduce the door model into the HyperMesh for geometric cleaning and mesh division. After checking and controlling the quality of the door mesh, according to the welding, bolt and glue-coated connection mode, The finite element model of each part is connected, and the material properties of the structural member are defined. The torsional stiffness, sag stiffness, lateral bending stiffness, modal frequency and concave resistance of the door are established. On the basis of the finite element model of the door, the simulation value of the performance of the door is calculated by Optistruct, and compared with the enterprise standard, all the performances accord with the design requirements, but there is still a large lightweight space. (3) first of all, there is a lot of light space for the performance of the car door. According to the results of the finite element analysis of the door and the experimental design of the parameters, eight design variables with large contribution were selected to sample the design samples. Secondly, based on the sampling data and the principle of response surface approximation model, an approximate model of door mass, stiffness, concave resistance and modal response surface is constructed, and the accuracy of the approximate model is tested. Finally, taking the selected door parts as the design variables, taking the door torsional stiffness, droop stiffness, lateral bending stiffness and concave resistance as the constraint conditions, the objective function is the minimum quality of the door and the maximum of the first third-order modal frequency of the door. The approximate model of door multi-objective optimization is constructed and solved by NSGA- 鈪，

本文編號(hào)：2445317