INTEGRATION SHAPE AND SIZING OPTIMIZATION OF COMPOSITE WING STRUCTURE BASED ON RESPONSE SURFACE METHOD

An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitable for these integrated shape/sizing optimization is obtained. The uniform design method is used to provide sample points, and approximation models for shape design variables. And the results of sizing optimization are construct- ed with the quadratic response surface method （QRSM）. The complex method based on QRSM is used to opti- mize the shape design variables and the criteria method is adopted to optimize the sizing design variables. Compared with the conventional method, the proposed algorithm is more effective and feasible for solving complex composite optimization problems and has good efficiency in weight cutting.

Aeroelastic Analysis and Optimization of High-aspect-ratio Composite Forward-swept Wings

In order to analyze the effects of forward-swept angle and skin ply-orientation on the static and dynamic aeroelastic characteristics, the aeroelastic modeling and calculation for high-aspect-ratio composite wings with different forward-swept angles and skin ply-orientation are performed. This paper presents the results of a design study aiming to optimize wings with typical forward-swept angles and skin ply-orientation in an aeroelastic way by using the genetic/sensitivity-based hybrid algorithm. Under the conditions of satiated multiple constraints including strength, displacements, divergence speeds and flutter speeds, the studies are carried out in a bid to minimize the structural weight of a wing with the lay-up thicknesses of wing components as design variabies. In addition, the effects of the power of spanwise variation function of lay-up thicknesses of skins and iugs on the optimized weights are also analyzed.

Structural Modeling and Aeroelastic Analysis of High-Aspect-Ratio Composite Wings

A unified structural model for high-aspect-ratio composite wing with arbitrary cross-section is developed. Two types of lay-ups of the composite wing, namely, circumferentially uniform stiffness （CUS） configuration and circumferentially asymmetric stiffness （CAS） configuration, are investigated. The present structural modeling method is validated through ANSYS FEM software for the case of a composite box beam. Then, the case of a single-cell composite wing with NACA0012 airfoil shape is considered. To investigate the aeroelastic problem of high-aspect-ratio composite wings, the linear ONERA aerodynamic model is used to model the unsteady aerodynamic loads under the case of small angle of attack. Finally, flutter speeds of the high-aspect-ratio wing with various composite ply angles are determined by using U-g method.

Stall Flutter Analysis of High-Aspect-Ratio Composite Wing

The stall flutter characters of high-aspect-ratio composite wing are investigated, and the effects of structure geometric nonlinearity and stiffness couple created by composite anisotropy on them also are discussed. Firstly, the high-aspect-ratio wing is modeled as a composite thin-walled closed section Euler beam whose displacement and rotation both could be of finite value, and the nonlinear dynamic equations is build up on it with all the effects of geometric nonlinearity, aerodynamic nonlinearity and anisotropy of material being considered. Then vibration equations are deduced through perturbing the dynamic equations at wing＇s equilibrium position, and coupled with unsteady stall aerodynamic model and ONERA model, to obtain the nonlinear stall flutter analysis equations of wing. Finally, the flutter stabilities with various wind speeds are determined by the harmonic balance method. With several exampies, the validity of the stall flutter model is proved, and the significant effects of geometric nonlinearity on the stall flutter various characters as wall as the effects of ply angle on the stall flutter speed and frequency also are discussed.

Tensile Deformation Properties of Corrugated Style Fiber Reinforced Composite Skin for a Morphing Wing

A type of skin structure which is made by a Circular Arc Corrugated Style Fiber Reinforced Composite （CACSFRC） is proposed to meet the requirements of the large and continuous deformation and high load capacity of a morphing wing skin. A mechanical model is developed to predict the tensile deformation properties and equiva- lent elastic modulus of the composite skin. Corrugated and plane skin samples are manufactured and tested. The theoretical analysis and tension tests show that CCSFRC skin has markedly much more tensile deforming capability than plane skin in the range of elasticity. The quantity of tensile deformation is in direct proportion to the number of ripples, and in inverse proportion to the cubic of ratio thickness, while the equivalent elastic modulus is in direct proportion to the cubic of ratio thickness approximately. Experiments prove that the predicted theoretical models are reliable and effective.

AEROELASTIC TAILORING OF AERONAUTICAL COMPOSITE WING STRUCTURES

This paper deals with the aeroelastic tailoring of aeronautical composite wing surfaces. The objective function is structural weight. Multi constraints, such as displacements, flutter speed and gauge requirements, are taken into consideration. Finite element method is used to the static analysis. Natural vibration modes are obtained by the spectral transformation Lanczos method. Subsonic doublet lattice method is used to obtain the unsteady aerodynamics.The critical flutter speed is generated by V-g method.The optimal problem is solved by the feasible direction method.The thickness of the composite wing skin is simulated by bicubic polynomials, whose coefficients combined with the cross-sectional areas or thicknesses of other finite elements are the design variables. The scale of the problem is reduced by variable linkage. Derivative analysis is performed analytically.Two composite wing boxes and a swept-back composite wing are optimized at the end of the paper.

复合材料机翼多工况下的自适应优化设计

为获得具有优良气动性能且兼具结构强度及轻量化的复合材料飞机机翼,提出考虑气动分析和结构分析多目标多工况优化方法。分别对机翼进行气动分析及结构强度分析,以机翼展弦比、锥度比、后掠角为几何优化变量,以机翼上下机翼蒙皮的-45°、90°、45°、0°层厚度和夹芯厚度为结构优化变量,建立以应力、位移为约束,以升阻比最大化和质量最小化为目标的协同优化模型。针对复合材料机翼多目标优化设计存在的计算量大难以取舍的问题,提出基于多准则和物理规划的自适应约束Kriging模型多目标优化算法(adaptive constraint kriging model multi-objective optimization algorithm based on multi-criteria and physical programming,AKBCP)。该算法引入了物理规划法和多准则加点,通过测试算例对比分析表明该算法具有较好的优化效果。将该算法应用到机翼多目标优化中,与初始机翼相比,优化后机翼升阻比提高3.12%,质量减轻31%,研究结果可为复合材料机翼优化设计提供参考。

纤维增强复合材料柔性封堵结构分析与验证

变弯度机翼展向翼端面封堵结构对于提升可变体机翼的变形精度、防止气流分离重要作用。本文针对刚柔耦合变弯度前缘结构,提出了以纤维增强复合材料为壳体,填充弹性基柔性材料的柔性封堵结构设计方案,建立了有限元模型在结构载荷作用下对其力学性能、封堵性能进行分析,制备所设计的柔性封堵结构并对其进行了试验验证。结果表明:(1)柔性封堵结构仿真模拟结果符合实际变形情况,最大应力为412.96 MPa,最大应变为4.15%;沿机翼弦向方向的位移从固定端向前缘逐渐变大,最大位移为6.28 mm;(2)所制备的柔性封堵结构在进行初次压缩试验后,其载荷值随位移的变化近似线性变化,满足变弯度机翼前缘的变形需求。

全碳纤维复合材料太阳能无人机机翼结构优化设计

针对大展弦比太阳能无人机的性能要求,开展碳纤维复合材料太阳能无人机机翼的优化设计。选用NACA4412为基准翼型,利用xfoil软件作为气动计算软件,基于NSGA-Ⅱ优化算法进行翼型优化。在此基础上对机翼进行三维建模,采用CFD软件进行气动特性分析,并利用ANSYS Workbench静力学模块对机翼进行流固耦合分析。结果表明:翼型优化后,升力系数提高4.20%,阻力系数降低8.74%,升阻比提高14.18%;在气动载荷作用下,从翼根向翼尖方向压力逐渐增大,翼尖处最大压力相对外界大气压力为242 Pa;在外载荷作用下,最大应力显示在翼根附近,为61.397 MPa,翼变形的最大值为40.262 mm,整体满足太阳能无人机的允许变形量在5%以内即翼尖变形不得大于半翼展长度值的5%的刚度要求。研究结果可为碳纤维复合材料太阳能无人机设计和研制提供理论参考。

复合材料机翼结构损伤建模与维修效果评估

当今,使用复合材料补片修复复合材料蒙皮损伤已成为常见做法。然而,目前对损伤位置影响的研究较少,而进行实验研究所需的成本也相对较高。该文利用ABAQUS有限元仿真软件对某型低速飞机的复合材料机翼进行静力学分析,并比较不同位置损伤条件下修复前后的力学性能。结果显示,损伤部位的最大位移与最大应力会随着翼展方向发生变化。此外,贴片修复能有效减少损伤部位承受的应力大小,为复合材料机翼结构损伤修复提供有效手段。

复合翼无人机高效发电系统的设计

为提升复合翼无人机的机动作战能力和扩大侦察范围,提出针对50 kg级复合翼无人机6 kW发电系统的设计方案,选型电气系统拓扑结构,实现电机起发一体;利用电机电磁理论计算确定永磁同步发电机的电枢设计参数,研究发动机的性能特性,结合电磁场计算模型和有限元仿真确定绕组形式,使发电机输出额定电功与发动机峰值工况转速匹配。发电机样机经地面台架测试,可实现起动发电一体,并可持续输出6 k W以上的额定电功率。发电系统为复合翼无人机建立了高效的能量流动关系,其能量密度高于锂聚合物电池15.4%,具有较好的机电匹配效果。

民机中央翼桁架肋结构布置优化设计

在民用飞机中央翼的轻量化设计过程中,可以采用桁架肋代替传统的腹板肋,但目前中央翼桁架肋结构的研究缺乏定量分析,如何合理地布置桁架肋内部的连杆结构已经成为重要的工程问题。为获得最优结构效率的桁架肋构型,本文提出了十种相同直径的桁架肋连杆结构布置构型,运用HyperSizer建立优化模型,以结构质量最小为优化目标,以桁架肋连杆数量与连杆连接方式为设计变量,通过不同构型方案的内力分布和结构效率对比研究获得桁架肋的影响规律。结果表明:当桁架肋连杆数量低于九根时,桁架肋重量与壁板重量趋近于收敛,减重可达16.1%;当桁架肋与前梁腹板采用连接方案时,桁架肋可分担前梁腹板所承受的载荷,降低了前梁重量,并提高了中央翼的整体结构效率。

面向某太阳能无人机机翼的梁结构设计制造与验证

太阳能无人机机翼具有典型的低翼载荷、大柔度、大展弦比特征,翼梁作为机翼的主承力结构,其承载能力与重量要求十分严格。如何提高翼梁结构承载效率,达到承载能力与重量的综合平衡,并实现大尺寸复合材料翼梁的整体化设计与制造,是太阳能无人机翼梁结构研究中的关键技术问题。本文首先针对太阳能无人机复合材料翼梁设计提出了一种快速选型及优化设计方法,该方法通过计算梁不同截面的承载能力来确定设计参数,同时考虑了铺层对称性、应变约束及稳定性约束,能够避免在方案阶段建立全机有限元模型并进行反复迭代计算,从而提高了翼梁结构的设计效率。其次,针对大尺寸复合材料圆管梁结构,提出了一种新型的专用成型方法,基于阴模成型实现了翼梁整体化制造并保证了制件成型质量,为类似的大型复合材料结构的制造工艺提供了参考。最后,开展了2 m量级圆管梁静力试验,典型截面的应变结果与设计结果误差不超过10%,验证了此快速优化设计方法的适用性。

基于改进型自抗扰控制的复合翼无人机旋翼控制系统设计与试验

针对多旋翼无人机在飞行过程中容易受到各种外部扰动的影响,以复合翼无人机的旋翼控制系统为研究对象,设计了一种自抗扰控制系统。首先,建立了多旋翼无人机系统运动学模型和动力学模型;其次,对自抗扰控制算法的特点展开研究,结合无人机模型分别设计了位置和姿态控制器。并改进了扩张状态观测器,引入了更精确的动力学模型,提升了扰动观测速度和估计精度,同时,降低了扩张状态观测器的阶数,提升了控制器调参简易性;再次,依据六自由度力和力矩的平衡方程,对本文研究对象搭建了控制分配模型。最终,采用Matlab/Simulink完成仿真模型设计和参数调节,对控制目标分别加入了内部重力扰动和外部风力扰动,仿真结果表明本文设计的控制器不仅可以很好地估计出系统内外扰动并进行补偿,而且具有极强的抗干扰性,可以保证无人机从初始点快速且平稳到达目标位置,并保持稳定悬停,姿态控制稳态误差在0.05°以内。

复合材料整体成型大后掠机翼设计与验证研究

根据机翼设计及材料工程力学性能要求,基于给定的机翼外形设计并制造了一种满足工程应用要求的全复合材料整体模压成型机翼结构。通过有限元仿真分析和工程静力学试验方法对该机翼结构进行了全面验证,有限元仿真分析结果与工程静力学试验结果吻合良好,满足复合材料工程力学许用值要求及机翼最大变形不大于半翼展长8%的刚度设计需求,该机翼的力学承载性能得到了充分验证。

某型无人机全复材机翼的胶接合拢工艺研究

随着全复材机翼在无人机上的广泛应用,对机翼制造工艺的系统研究也成为当务之急。本文以高亚音速无人机全复材机翼为基础,通过生产测试,并从施工环境、工装夹具、界面状态、材料选型、固化工艺、胶层厚度等多个工艺维度对测试结果进行分析研究。研究结果表明,随着胶接合拢工艺的优化,机翼性能得到了极大提升,不仅顺利通过了3 g载荷静力试验,还完成了6 g载荷飞行验证,该研究分别从理论和实践层面为复材机翼等制件的胶接合拢提供了工艺指南。

鼻翼退缩矫正方法的选择策略与临床效果分析

目的 分析鼻翼缘轮廓线移植物、外侧脚支撑移植物、耳软骨复合组织移植物矫正鼻翼退缩的临床效果。方法 自2020年10月至2022年10月,我院收治的108例鼻翼退缩患者作为研究对象。在肋软骨隆鼻的同时进行鼻翼退缩矫正。对76例轻到中度鼻翼退缩,并没有前庭黏膜皮肤组织缺乏的患者应用鼻翼缘轮廓线移植物,22例鼻翼退缩并外鼻阀塌陷或鼻翼退缩是由于外侧脚头侧异位造成,并没有皮肤及软组织缺乏的患者应用外侧脚支撑移植物,10例重度鼻翼退缩或退缩的鼻翼是由于皮肤及软组织疤痕挛缩,缺乏弹性造成的患者应用耳软骨复合组织移植物,来改善鼻翼退缩,并进行疗效评价。结果108例鼻翼退缩患者术后随访12-24个月,术后1年鼻翼缘向尾侧推进距离:应用鼻翼缘轮廓线移植物76例患者为(2.1±0.5)mm;应用外侧脚支撑移植物22例患者为(2.7±0.9)mm;应用耳软骨复合组织移植物10例患者为(3.2±0.8) mm。未出现感染、鼻通气功能障碍、鼻尖夹捏畸形、鼻孔不对称等并发症;鼻翼未出现塌陷,鼻翼缘位置相对稳定。患者满意度为97.22%。术后鼻部测量指标与术前比较,差异有统计学意义(P<0.05)。结论 根据鼻翼退缩情况合理选用鼻翼缘轮廓线移植物、外侧脚支撑移植物、耳软骨复合组织移植物可以有效矫正鼻翼退缩。

FSAE赛车尾翼曲率端板的设计及制备

基于FSAE赛事,通过CFD分析方法设计并优化尾翼端板形状,并总结出一套碳纤维复合材料端板加工流程以提升尾翼的气动效率和刚度表现。首先,根据后处理云图、流线图的变化规律和匹配原则,结合数字化设计过程,确定了大曲率端板外形最佳方案,以减小前部空气动力学装置及驾驶舱湍流尾迹对流经尾翼气流的干扰,并在端板下部分设置尾翼整体部件的额外支撑点,拟达到优化流场和尾翼结构刚度、提升装置机械稳固性的目的。随后,制作成品并总结出一套完善的碳纤维复合材料尾翼端板制备方案,证明相关设计的可行性。

Aeroelastic Optimization of the High Aspect Ratio Wing with Aileron

In aircraft wings,aileron mass parameter presents a tremendous effect on the velocity and frequency of the flutter problem.For that purpose,we present the optimization of a composite design wing with an aileron,using machine-learning approach.Mass properties and its distribution have a great influence on the multi-variate optimization procedure,based on speed and frequency of flutter.First,flutter speed was obtained to estimate aileron impact.Additionally mass-equilibrated and other features were investigated.It can deduced that changing the position and mass properties of the aileron are tangible following the speed and frequency of the wing flutter.Based on the proposed optimization method,the best position of the aileron is determined for the composite wing to postpone flutter instability and decrease the existed stress.The represented coupled aero-structural model is emerged from subsonic aerodynamics model,which has been developed using the panel method in multidimensional space.The structural modeling has been conducted by finite element method,using the p-k method.The fluid-structure equations are solved and the results are extracted.

尾座式电动飞机复合材料机翼结构优化设计

以复杂地形地区物资快速投送平台设计为背景,开展尾座式电动飞机复合材料机翼设计研究。对机翼结构载荷进行分析,对机翼结构构件布置和铺层进行设计,形成复合材料机翼结构设计方案。建立复合材料机翼结构有限元模型,开展典型工况条件下的静力分析,得到机翼结构变形、应力和Tsai-Wu失效因子分布。采用分步优化策略,以机翼结构铺层厚度和铺层角度为设计变量,开展机翼结构质量优化计算,优化结果表明,优化后的机翼结构在满足强度和刚度要求下质量减轻约47.77%,可为尾座式电动飞机结构设计提供重要参考。