不等开口纤维增强树脂复合材料缠绕壳体非测地线线型设计

线型设计是纤维增强树脂（FRP）复合材料缠绕壳体设计的一项重要研究内容,它对壳体FRP复合材料缠绕制品的质量起关键作用。本文针对不等开口极孔或不同形状封头的FRP复合材料压力容器壳体,基于非测地线缠绕方程,提出了一套非测地线缠绕线型设计方法,建立了根据已知缠绕线型和芯模转角来确定相应的切点数和纱片宽度的计算模型,开发出了一套FRP复合材料缠绕壳体仿真软件系统,对非测地线缠绕线型进行了计算机图像仿真与检验。结果表明:各个设计区间的仿真结果满足设计要求,没有出现缠绕角突变、纤维分布不规律和纤维在局部严重重叠等异常现象。该仿真软件系统可以为工程人员在实际壳体缠绕之前提供参考,缩短缠绕线型迭代试错周期,同时也为后续缠绕角及缠绕顺序等缠绕参数的优化奠定了基础。      

基于机器人的复合材料缠绕策略优化

基于机器人的复合材料缠绕不同缠绕策略会对缠绕工艺及机器人运动稳定性产生影响, 为获得使机器人运动稳定性更优的缠绕策略, 研究了6自由度工业机器人的复合材料缠绕工作站, 单独分析了包络形式、悬纱长度以及测地线/非测地线缠绕等参数对缠绕工艺及机器人运动稳定性的变化参数的影响, 采用MATLAB进行不同缠绕策略的机器人缠绕轨迹计算, 确定规划后的缠绕轨迹, 基于ADAMS和MATLAB进行机器人缠绕动力学联合仿真, 获取机器人各关节力矩曲线, 分析规划后的缠绕轨迹对机器人运动稳定性的影响。进行了复合材料制品干纤维缠绕实验, 缠绕实验表明:采用优化后的缠绕策略进行复合材料制品缠绕时缠绕线型稳定, 缠绕过程无滑纱、交叠、架空等现象, 缠绕精度完全满足设计要求。      

纤维缠绕复合材料环形容器设计优化(英文)

纤维缠绕环形容器可充分利用空间,节省结构质量和消除系统质心漂移,目前在很多工业领域中发挥着日益重要的作用。本文基于复合材料层合理论和测地线缠绕原理,提出了纤维缠绕环形压力容器的线型优化设计方法。应用微分几何,导出了圆环面上测地缠绕轨迹和纤维不架空判据。以初始缠绕角和缠绕层厚度为变量,对结构重量进行最小化设计,得到了对应于不同管径比的优化缠绕线型。对优化线型进行了计算机缠绕仿真,并给出了缠绕铺层的各向正轴应力分布。结果表明,优化设计的缠绕线型模式精确可靠,满足纤维缠绕的基本要求。纤维缠绕角度大小更趋于合理,从而能充分发挥缠绕结构的力学性能,减经系统重量,使优化得到的环形容器结构性能比传统测地线缠绕环形容器有很大提高。本文的设计计算方法可直接用于复合材料环形气瓶的初步设计。     

基于非测地线纤维缠绕压力容器线型设计与优化

为较好地满足纤维轨迹路径的稳定与均布,与传统测地线缠绕模式不同,提出了非测地线纤维缠绕压力容器的纤维线型方程,给出了非测地线型模式和缠绕参数的最优化设计方法,分析了环形缠绕机芯模和丝嘴的相对缠绕速比,结合均匀布满条件对优化线型进行了调整。将计算机仿真技术应用到环形容器的缠绕线型设计与验证中,研究了CAD系统各组成模块的功能及实现方法,对非测地线缠绕成型进行了计算机图形仿真与检验。结果表明:设计得到的非测地线满足缠绕工艺的基本要求;采用最优化的非测地线模式进行缠绕,可使非测地线缠绕角集中在筒形压力容器的最佳缠绕角55°附近,有效提高了压力容器的结构承载性能。      

纤维缠绕复合材料壳体刚度衰减模型数值模拟

应用微分几何理论,推导出纤维缠绕复合材料壳体的非测地线缠绕轨迹、包角方程及绕丝头运动方程,得到缠绕过程的动态仿真模拟数据。将封头处变化的缠绕角、厚度等实际工艺参数直接用于壳体结构的理论分析。采用叠层的增量本构关系,模拟层合板壳结构的损伤过程,建立了损伤后刚度衰减模型及刚度退化准则,并通过实验确定了刚度衰减系数。应用此模型对纤维缠绕复合材料压力容器进行了数值分析。结果表明:纤维缠绕复合材料压力容器封头处损伤会导致其弯曲刚度降低,这是影响轴向变形的重要因素。      

纤维缠绕环形压力容器线型设计与仿真

纤维缠绕环形容器要求满足线型稳定和结构优化两个条件.基于微分几何理论,提出了用于复合材料环形压力容器成型的纤维缠绕线型,分析了芯模和吐丝嘴的缠绕速比,给出了缠绕参数优化设计方法.在对优化线型进行分析的基础上,模拟环形容器的纤维缠绕过程,实现了环形容器成型的计算机优化与图形仿真.通过应用缠绕仿真系统,可以检验线型模式的正确性和可行性.结果表明,优化设计的线型模式精确可靠,满足纤维缠绕的基本要求,为微机控制环形容器缠绕奠定了理论基础.     

T700碳纤维增强树脂复合材料气瓶封头非测地线缠绕强度

利用微分几何理论和四阶龙格库塔法求解气瓶封头上T700碳纤维增强树脂复合材料（CFRP）非测地线缠绕角微分方程,得到稳定的非测地线缠绕轨迹;利用有限元仿真软件建立T700 CFRP缠绕气瓶有限元模型,分析不同非测地线轨迹对工作压力（30 MPa）下T700 CFRP缠绕气瓶强度的影响,并采用渐进损伤模型分析爆破压力的变化规律。对于封头高h=50 mm的T700 CFRP缠绕气瓶,滑线系数为0.2时承载能力最强,比T700 CFRP测地线缠绕气瓶提高了7 MPa,约为6.4%;对于封头高h=160 mm的T700 CFRP气瓶,滑线系数为0.2时承载能力最强,比T700 CFRP测地线缠绕气瓶提高了6 MPa,约为11.5%。结果表明,优化设计得到的缠绕线型既能满足缠绕工艺的基本要求,又提高了T700 CFRP缠绕气瓶的结构力学性能,可为实际缠绕工艺提供参考。      

钛内衬复合材料环形气瓶结构设计与优化EI北大核心CSCD

根据微分几何,推导环形气瓶测地线缠绕轨迹以及缠绕角应满足的稳定缠绕条件,并针对不同切点数进行线型轨迹仿真。基于有限元分析,针对钛合金内衬环形气瓶的初始缠绕角及缠绕层数进行优化设计,并评估对比有、无环向补强层的环形气瓶承载能力。结果表明:本文设计的测地线轨迹精确可靠,很好地满足环形气瓶的缠绕工艺性。优化设计的缠绕参数既满足工艺可缠性,又能提高环形气瓶的结构性能。此外,有环向补强层的气瓶爆破强度提高了14%,钛合金内衬屈服强度提高了24.8%。因此,采用环向补强层有利于进一步提高环形气瓶的承载性能。水压实验结果表明本文设计方法预测的变形和爆破压力与实验值吻合良好。     

纤维缠绕玻璃钢三通管的研究

本文分析了中间为偏心球体的玻璃钢三通管缠绕规律,给出了纤维在臂-球-臂缠绕时架空高度计算式。文中分别讨论了三通管的测地线和非测地线缠绕,指出用单一线型进行测地线缠绕时,在柄-球交接处存在一微小三角空白区,需要进行补强,本文还推导了丝嘴平面运动时的运动方程,讨论了避免芯模与丝嘴碰撞的条件,为在价廉的计算机控制的简单缠绕机上实现中间为偏心球体的玻璃钢三通的缠绕提供了依据。      

缠绕纤维与芯模表面间滑线系数的测量表征

提出了一种新的滑线系数测量方法, 并基于一般曲面稳定缠绕条件, 设计了一种能够简便快捷测量滑线系数的新型芯模。该芯模在固定缠绕角情况下, 沿母线方向任意点处的纬度圆半径与该点的滑线系数之间满足线性关系。利用该方法及其装置对碳纤维和玻璃纤维在不同缠绕速度、缠绕张力和胶液黏度等条件下与铝质芯模间的滑线系数进行了测量表征。研究结果表明, 该方法可为缠绕纤维与芯模表面间滑线系数的测量及非测地线缠绕轨迹规划设计提供依据。     

考虑纤维体积含量变化的纤维缠绕厚壁柱形结构的等强度设计

纤维缠绕厚壁柱形管道或容器在缠绕张力作用下会使缠绕纤维层的应力状态不断变化,形成沿壁厚力学性能非均匀的结构。依据缠绕过程中的纤维束应力状态分析和纤维束本构关系,获得了纤维体积含量与所受应力状态的关系。基于正交各向异性本构关系和双层筒模型的离散叠加法,建立了给定缠绕张力确定纤维缠绕厚壁柱形结构剩余张力的计算方法,并计算了等张力缠绕纤维层的纤维体积含量沿壁厚的分布。利用Tsai-Wu失效准则研究了纤维体积含量非均匀的厚壁柱形结构的纤维层强度。研究表明:缠绕工艺使内层纤维体积含量和强度均略高于外层,纤维缠绕厚壁柱形结构的强度分析和设计时应考虑这种影响;利用变化的缠绕张力设计可以实现强度比沿壁厚的均匀分布。     

缠绕线型对缠绕复合材料圆管轴向拉伸失效的影响

采用细观刚度模型的有限元分析（FEA）与改进的逐渐累积损伤方法相结合,建立了缠绕复合材料圆管轴向拉伸失效的分析方法与流程,以揭示缠绕线型对缠绕复合材料损伤失效的影响。对沿圆周方向分布有1个、3个和5个单胞的3种不同线型的缠绕复合材料圆管试件进行轴向拉伸破坏实验,获得其失效形式、平均拉伸强度及其随缠绕线型的变化规律。研究表明：缠绕复合材料圆管轴向拉伸失效主要以丧失承载能力的功能失效为主,缠绕线型对其拉伸强度有一定的影响;数值分析结果表明,轴向拉伸过程中,主要损伤为基体开裂与基纤剪切,纤维交叉容易引起损伤起始与扩展。     

Halbzeugoptimierung und Anwendungen von Thermoplastwickelverbunden

Optimation of semi-finished products and application of thermoplastic filament winding With an experimental, PC-controlled filament winding device (for thermoplastic materials) unidirectional semi-finished products (commingled yarns) are manufactured into long-fiber reinforced composites. The aim is to optimize this technology through the parameters of the hybrid yarns used. As reinforcing materials glass and carbon fibers and as matrix materials PA6 and PP are used. The influence of (glass fiber) size, glass fiber content, yarn type, structure and thickness of the hybrid yarn, as well as the type of reinforcing fibers are determined in the ring tensile test and the interlaminar shear test. The structure of the composite was investigated by REM, GPC, DSC and WAXS. Examples of a successful combination of long-fiber reinforced filament wound structures and the injection moulding technology are available.     

Development of a new generation of filament wound composite pressure cylinders

A new generation of composite pressure vessels for large scale market applications has been studied in this work. The vessels consist on a thermoplastic liner wrapped with a filament winding glass fibre reinforced polymer matrix structure. A high density polyethylene (HDPE) was selected as liner and a thermosetting resin used as matrix in the glass reinforced filament wound laminate.     

Finite element modeling of the filament winding process

A finite element model of the wet filament winding process was developed. In particular, a general purpose software for finite element analysis was used to calculate the fiber volume fraction under different process conditions. Several unique user defined subroutines were developed to modify the commercial code for this specific application, and the numerical result was compared with experimental data for validation. In order to predict the radial distribution of the fiber volume fraction within a wet wound cylinder, three unique user defined subroutines were incorporated into the commercial finite element code: a fiber consolidation/compaction model, a thermochemical model of the resin and a resin mixing model. The fiber consolidation model describes the influence of the external radial compaction pressure of a new layer as it is wound onto the surface of existing layers. The thermochemical model includes both the cure kinetics and viscosity of the resin. This model analyzes the composite properties and tracks the viscosity of the resin, which is a function of the degree of cure of the resin. The resin mixing model describes the mixing of “old” and “new” resin as plies are compacted. Validations were made by comparing image analysis data of fiber volume fraction in each ply for filament wound cylinders with the FEM results. The good agreement of these comparisons demonstrated that the FEM approach has can predict fiber volume fraction over a range of winding conditions. This approach, then, is an invaluable tool for predicting the effects of winding parameters on cylinder structural quality.     

Stability of fiber trajectories for winding toroidal pressure vessels

In this paper the fiber trajectory stability of filament wound toroidal pressure vessels is evaluated for two most frequently used patterns: single helical winding, helical and hoop winding. The basic equations of equilibrium for fibers on a torus are given based on netting analysis. The governing equations that determine helical winding angles along the meridional direction are derived for the two winding patterns. The slippage coefficients of the obtained fiber trajectories are calculated using the non-geodesic law and differential geometry. The condition between the hoop-to-helical thickness ratio and the relative bend radius of the toroid is also formulated to prevent fiber bridging on the concave surface. The fiber slippage and bridging tendencies are outlined and compared, corresponding to various relative bend radii and hoop-to-helical thickness ratios. The results show that the single helical winding process provides better stability of fiber trajectories, in terms of both fiber slippage and bridging, than the helical and hoop winding. The toroidal vessel with larger relative bend radius requires lower coefficient of friction between the fiber bundle and the supporting surface. The present analysis for fiber trajectory stability affords a useful reference tool for designing filament-wound toroidal pressure vessels.     

环面上非测地线缠绕方程

本文分析了非测地线稳定缠绕的条件,用微分几何中法曲率和短程曲率概念给出了环面上非测地线缠绕方程,为缠绕弧形管提供了依据。