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1.
基于改进模拟退火算法的复合材料层合板频率优化   总被引:1,自引:0,他引:1       下载免费PDF全文
针对复合材料层合板频率优化问题,结合可行规则法和直接搜索模拟退化算法,提出了一种自适应模拟退火(SA)改进算法。层合板优化目标是基频、频率带隙以及给定基频和带隙约束的层合板厚度。设计变量包括铺层角度和铺层数两种离散变量。改进算法的自适应新点产生模块采用依赖温度的动态调整搜索半径,改善了直接搜索模拟退化(DSA)算法易陷入局部极值的缺陷,而可行规则法的引入提高了SA算法求解约束问题的效率和简易性。采用Ritz法进行频率响应分析以考虑弯扭耦合影响。不同铺层数、角度增量和长宽比时的层合板3类算例结果显示:改进算法能有效求解层合板频率优化,可获得更多或更好的铺层顺序全局优化解。  相似文献   

2.
针对层合板铺层优化问题,提出一种改进鲸鱼算法(improved whale optimization algorithm,IWOA)。通过引入对立学习策略保持进化过程的多样性,同时结合非线性收敛因子和自适应阈值提高IWOA的全局搜索能力;以层合板的铺设角度为设计变量、基频及带隙为优化目标进行板的频率优化,并使用Ritz法求解。基于IWOA算法对长宽比分别为1和2的复合材料矩形层合板进行优化研究,并与鲸鱼优化算法(whale optimization algorithm,WOA)、分层优化算法(layered optimization algorithm,LOA)和差分进化算法(differential evolution algorithm,DEA)进行比较分析。结果表明,相较于LOA、DE和WOA算法,IWOA具有更好的全局收敛性,且在处理多模态问题时更具可靠性。  相似文献   

3.
针对复合材料层合板结构出现的噪声问题,将响应面法RSM(Response Surface Method)与遗传优化算法相结合,提出一种降低复合材料层合板声压级的优化方法。该方法基于四边形复合材料层合板结构建立有限元分析模型,通过三因子试验设计点设计试验计划表,结合最小二乘法构建复合材料层合板声压级的2阶响应面近似模型。以影响层合板噪声的显著因子为设计变量,层合板的声压级为设计目标,采用遗传算法对响应面近似模型进行优化,结果表明,使用该方法对复合材料层合板的噪声特性进行分析,可明显提高优化效率并为工程实际提供参考。  相似文献   

4.
孙士平  曾庆龙  胡政 《复合材料学报》2016,33(12):2860-2868
采用广义微分求积(GDQ)法开展了不同边界条件下承受面内线性变化载荷作用复合材料层合板振动与屈曲的分析与优化。针对GDQ法求解面内线性变化载荷工况复合材料层合板屈曲问题存在计算振荡、不收敛现象,提出载荷扰动策略实现了GDQ法对复合材料层合板屈曲问题的稳定高效求解。基于基础圆频率和临界屈曲载荷系数的归一化指标,分析了铺层角度对复合材料层合板综合性能的影响,并结合直接搜索模拟退火算法开展了复合材料层合板的铺层顺序优化。结果表明:铺层角度变化对屈曲性能的影响明显强于频率特性;面内线性变化载荷中,以弯曲载荷作用下复合材料层合板的优化综合性能受边界条件变化的影响最小,而优化铺层角度受边界条件变化的影响最大。研究结果为复杂载荷作用下复合材料层合板的设计提供了参考。  相似文献   

5.
谢桂兰  赵锦枭  曹尉南 《材料导报》2014,(6):153-157,149
运用均匀化理论与有限元相结合的方法,预测了风机叶片复合材料层合板的性能。将复合材料层合板内部结构分为宏观、细观和纳观3个层次,建立了复合材料层合板的多尺度模型。通过3次均匀化方法,并编写APDL程序输入商业软件ANSYS,预测材料各参数(碳纳米管体积分数、长径比、弹性模量,纳米薄层体积分数、弹性模量)对复合材料层合板性能的影响。结果表明,当分别增大碳纳米管体积分数、长径比、弹性模量以及纳米薄层体积分数、弹性模量时,风机叶片复合材料层合板的性能均能得到提高。同时表明加入一定量的碳纳米管可以适当提高复合材料层合板的性能。实验结果对风机叶片复合材料的制备有一定的指导作用。  相似文献   

6.
李根  吴锦武 《声学技术》2017,36(4):371-377
以层合板结构的临界屈曲载荷系数最大化为优化目标,基于改进型模拟退火算法对层合板结构铺设角度和铺层顺序进行优化。由于层合板结构的铺层角度是离散变量,模拟退火算法适合求解离散变量的优化问题。利用模拟退火算法优化层合板铺层,在算法内采用并行计算、引入记忆功能同时设置双阈值终止准则,有效地提高了优化过程的收敛速度,同时避免优化过程中出现局部最优解。以临界屈曲载荷系数作为目标函数,选取复合材料层合板的铺设角度顺序为设计变量,采用改进的模拟退火算法得出复合材料层合板的最优铺设角度以及铺层顺序。  相似文献   

7.
吴锦武  赵飞  王县委  李根 《声学技术》2016,35(2):155-161
利用遗传算法对复合材料层合板结构的固有频率间隔和辐射声功率进行双目标优化设计。利用分层理论结合有限元模型求解层合板的固有频率和振速分布。通过声辐射模态理论,计算层合板结构辐射声功率。以铺设角度作为设计变量,第一阶与第二阶固有频率间隔和辐射声功率作为双目标优化目标函数,以某4层的层合板结构为例,采用目标加权法优化目标函数。研究了不同权重系数、不同频率时固有频率间隔最大化和声功率最小化对应的优化铺设角度。由数值分析结果可知:不同的权重系数比下获得的Pareto最优解不同;在同一权重系数下,两个优化目标所起的作用不尽相同;随着频率的增加,选择相对较大的权重系数可使Pareto最优解较好地兼顾两个优化目标。  相似文献   

8.
基于遗传算法对碳纤维增强树脂复合材料(CFRP)层合板单搭胶接结构进行了多目标优化,以提高其结构性能。首先,通过三维Hashin准则和三角形内聚力模型建立三维有限元模型来预测CFRP层内损伤过程、层间失效和胶层损伤过程,并通过试验验证其有效性。其次,利用拉丁超立方抽样(LHS)方法和二次多项式响应面法(RSM),基于搭接长度、胶层厚度和被胶接件宽度等胶接参数建立以拉伸强度和剪切强度为目标函数的多目标优化代理模型。最后,基于遗传算法(GA)对拉伸强度和剪切强度代理模型进行优化,得出一组Pareto解集,并基于理想解排序方法(TOPSIS)对Pareto非劣解集进行折中处理,得到最好的胶接参数设计方案。结果表明:CFRP层合板单搭胶接结构的数值模拟结果与试验结果相比具有很高的吻合度,验证了有限元方法的可靠性;CFRP层合板单搭胶接结构的拉伸强度和剪切强度与搭接长度、胶层厚度和被胶接件宽度具有显著的关联性;二次响应面代理模型结果与数值模拟结果相比误差均小于2.3%;与常规的单搭胶接结构方案进行对比,搭接拉伸强度和剪切强度分别提高了2.65%和17.24%。   相似文献   

9.
复合材料结构损伤机理复杂,其损伤破坏一般呈现缓慢扩展趋势。为了有效地对复合材料结构健康状态进行预测,将距离形态相似度(DMS)和最小二乘支持向量机(LS-SVM)模型引入复合材料结构健康状态预测中,提出了基于DMS和LS-SVM的复合材料结构健康状态预测方法。首先,以复合材料层合板(T300/QY8911)为具体研究对象,对其进行损伤试验,采集其振动加速度作为表征其健康状态的原始信息,并进行小波包分解,利用分解得到的各个频带信号的样本熵作为特征向量;然后,采用距离形态相似度(DMS)方法确定结构健康指数;最后,将结构健康指数作为建模数据用以构建LS-SVM预测模型,预测复合材料结构健康指数。结果表明,该方法可以有效实现复合材料结构裂纹损伤的预测,具有很好的应用前景。  相似文献   

10.
根据复合材料工字型加筋壁板的工艺铺设特点,建立了一种特殊的有限元模型,将工字型筋条按照凸缘顶板、[形腹板、凸缘底板、以及蒙皮四个层合板进行建模。针对工字型加筋壁板的铺层特征,本研究采用二级优化策略对工字型加筋壁板进行以静强度、刚度和稳定性为约束条件的轻量化设计,与一级优化(铺层厚度和弯曲刚度系数的调整)相比,二级优化采用改进的自适应遗传算法优化层合板的铺层顺序,优化设计结果可以直接用于工程应用,有限元模型和优化方法对复合材料工字型加筋壁板的设计具有指导意义。  相似文献   

11.
The optimal design of laminated sandwich panels with viscoelastic core is addressed in this paper, with the objective of simultaneously minimizing weight and material cost and maximizing modal damping. The design variables are the number of layers in the laminated sandwich panel, the layer constituent materials and orientation angles and the viscoelastic layer thickness. The problem is solved using the Direct MultiSearch (DMS) solver for multiobjective optimization problems which does not use any derivatives of the objective functions. A finite element model for sandwich plates with transversely compressible viscoelastic core and anisotropic laminated face layers is used. Trade-off Pareto optimal fronts are obtained and the results are analyzed and discussed.  相似文献   

12.
A. Houmat 《工程优选》2018,50(2):205-217
The optimal lay-up design for the maximum fundamental frequency of variable stiffness laminated composite plates is investigated using a layer-wise optimization technique. The design variables are two fibre orientation angles per ply. Thin plate theory is used in conjunction with a p-element to calculate the fundamental frequencies of symmetrically and antisymmetrically laminated composite plates. Comparisons with existing optimal solutions for constant stiffness symmetrically laminated composite plates show excellent agreement. It is observed that the maximum fundamental frequency can be increased considerably using variable stiffness design as compared to constant stiffness design. In addition, optimal lay-ups for the maximum fundamental frequency of variable stiffness symmetrically and antisymmetrically laminated composite plates with different aspect ratios and various combinations of free, simply supported and clamped edge conditions are presented. These should prove a useful benchmark for optimal lay-ups of variable stiffness laminated composite plates.  相似文献   

13.
This paper presents a multiobjective optimization methodology for composite stiffened panels. The purpose is to improve the performances of an existing design of stiffened composite panels in terms of both its first buckling load and ultimate collapse or failure loads. The design variables are the stacking sequences of the skin and of the stiffeners of the panel. The optimization is performed using a multiobjective evolutionary algorithm specifically developed for the design of laminated parts. The algorithm takes into account the industrial design guidelines for stacking sequence design. An original method is proposed for the initialization of the optimization that significantly accelerates the search for the Pareto front. In order to reduce the calculation time, Radial Basis Functions under Tension are used to approximate the objective functions. Special attention is paid to generalization errors around the optimum. The multiobjective optimization results in a wide set of trade-offs, offering important improvements for both considered objectives, among which the designer can make a choice.  相似文献   

14.
A multi-start global optimization technique is used to investigate the lamination arrangements of laminated composite plates designed for maximum stiffness. The multi-start global optimization technique which originated from the concept of minimizing the potential energy of a moving particle in a conservative force field is extended to the optimal design of laminated composite plates in which the strain energies of the plates are minimized. The optimization algorithm has been proved to be efficient and effective in producing the global optima. Numerical examples of the selection of optimal lamination arrangements of symmetrically laminated composite plates with different aspect ratios subject to different loading conditions are given. The results show that aspect ratio, loading condition and material property can affect the optimal lamination arrangement.  相似文献   

15.
In this study the layer optimization was carried out for maximizing the lowest (first) fundamental frequency of symmetrical laminated composite plates subjected to any combination of the three classical boundary conditions, and the applicability of the Artificial Bee Colony (ABC) algorithm to the layer optimization was investigated. The finite element method was used for calculating the first natural frequencies of the laminated composite plates with various stacking sequences. The ABC algorithm maximizes the first natural frequency of the laminated composite plate defined as an objective function. The optimal stacking sequences were determined for two layer numbers, twenty boundary conditions and two plate length/width ratios. The outer layers of the composite plate had a stiffness increasing effect, and as the number of clamped plate edges was increased both he stiffness and natural frequency of the plate increased. The optimal stacking sequences were in good agreement with those determined by the Ritz-based layerwise optimization method (Narita 2003: J. Sound Vibration 263 (5), 1005–1016) as well as by the genetic algorithm method combined with the finite element method.  相似文献   

16.
The optimal lamination arrangements of laminated composite plates with maximum stiffness subject to side constraints are investigated via a constrained multi-start global optimization approach. In the optimal design process, the deformation analysis of laminated composite plates is accomplished by utilizing a shear deformable laminated composite finite element and the optimal design problem, which has been converted into an unconstrained minimization problem via the general augmented Lagrangian method, is solved by utilizing the proposed unconstrained multi-start global optimization technique to determine the optimal fiber angles and layer group thicknesses of the laminated composite plates for attaining maximum stiffness and simultaneously satisfying the imposed side constraints. The feasibility of the proposed constrained multi-start global optimization algorithm is validated by means of a simple but representative example and its applications are demonstrated by means of a number of examples on the maximum stiffness design of symmetrically laminated composite plates. The effects of length-to-thickness ratio, aspect ratio, and number of layer groups upon the optimum fiber angles and layer group thicknesses of the plates are investigated.  相似文献   

17.
A. Guenanou 《工程优选》2018,50(5):766-780
The optimum stacking sequence design for the maximum fundamental frequency of symmetrically laminated composite circular plates with curvilinear fibres is investigated for the first time using a layer-wise optimization method. The design variables are two fibre orientation angles per layer. The fibre paths are constructed using the method of shifted paths. The first-order shear deformation plate theory and a curved square p-element are used to calculate the objective function. The blending function method is used to model accurately the geometry of the circular plate. The equations of motion are derived using Lagrange’s method. The numerical results are validated by means of a convergence test and comparison with published values for symmetrically laminated composite circular plates with rectilinear fibres. The material parameters, boundary conditions, number of layers and thickness are shown to influence the optimum solutions to different extents. The results should serve as a benchmark for optimum stacking sequences of symmetrically laminated composite circular plates with curvilinear fibres.  相似文献   

18.
Material characterization of laminated composite plates via static testing   总被引:3,自引:0,他引:3  
A minimization method for material characterization of laminated composite plates using static test results is presented. Mechanical responses such as strains and displacements are measured from the static tests of the laminated composite plates. The finite element method is used to analyse the deformation of the laminated composite plates. An error function is established to measure the differences between the experimental and theoretical mechanical responses of the laminated composite plates. The identification of the material elastic constants of the laminated composite plates is formulated as a constrained minimization problem in which the elastic constants are determined by making the error function a global minimum. A number of examples are given to illustrate the feasibility and applications of the proposed method.  相似文献   

19.
Reliability predictions of laminated composite plates with random system parameters subjected to transverse loads are performed using different methods. System parameters such as material properties, layer thicknesses, and lamina strengths of a laminated composite plate are treated as base-line random variables and an appropriate failure criterion is used to construct the limit state equation of the plate in the reliability analysis. Based on the statistics of the base-line random variables obtained from experiments, different methods, namely, Monte Carlo method, β method, and first-order second moment method, are used to calculate the reliability of the laminated composite plates. In the first-order second moment method, the stochastic finite element method is used to derive for the statistics of the first-ply failure load of the laminated composite plates from those of the base-line random variables. The reliability of the laminated plate is then computed using the theoretically determined statistics together with an assumed probability distribution function of the first-ply failure load. The feasibility and accuracy of the different methods are studied by means of the experimental data of centrally loaded laminated composite plates with different lay-ups. The suitability of several commonly used failure criteria for reliability analysis of laminated composite plates is also investigated by means of several examples.  相似文献   

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