板锥网壳结构复合材料层合板的强度分析

板锥网壳结构是一种受力性能合理、技术经济效益良好的新型空间结构形式.本文结合复合材料力学理论和复合材料结构力学(板壳理论),采用组合结构有限元对复合材料层合板自身的强度和主要影响因素进行全面和深入的研究,研究复合材料板锥网壳结构的受力性能,为复合材料板锥网壳结构设计和层合板铺层设计提供理论上的依据,得出了可应用于工程实践的重要结论.     

复合材料帽型加筋层合板典型板元的等效刚度计算

基于经典层合板理论和刚度等效原理,推导了复合材料帽型加筋层合板典型板元的等效面内刚度和等效弯曲刚度的理论解,通过具体算例,将多种工况下典型板元的受力响应和Abaqus有限元计算结果进行比较,结果显示理论解和有限元计算结果吻合较好,说明理论计算方法是准确可靠的。本文的研究成果可应用于复合材料加筋层合板和单板骨架式复合材料船体结构的刚度计算。     

板壳式换热器的应用和进展

评述了近年来有关板壳式换热器的研究进展,着重介绍了板壳式换热器的结构、性能特点和制造技术.还介绍了板壳式换热器的工业应用情况.     

纤维层合板梯度化后对弯曲刚度与层间应力的影响

本文介绍了纤维层合板力学梯度设计的新概念,以平纹正交织物复合材料为例,用板壳弯曲的有限元法,探讨了层合板的最佳弯曲刚度.     

大开口复合材料网格加筋锥壳的稳定性分析

本文用有限元法计算了受轴压，外压，以及轴压和外压联合作用下的大开口复合材料网格加筋锥壳的稳定性分析，从而得出不同铺层角度，不同受力工况下的大开口圆锥壳的临界载荷，并将受轴压的锥壳的计算值与实验值进行了比较。     

轴压作用下缠绕复合材料夹芯圆柱壳力学性能研究

为研究缠绕复合材料夹芯圆柱壳的力学特性,首先开展了缠绕复合材料夹芯圆柱壳模型的轴向压缩试验,得到载荷-位移曲线与应变分布规律;进而,依据复合材料经典层合板理论,将缠绕圆柱壳模型的内外蒙皮均匀化,等效为单向纤维增强复合材料,采用ABAQUS有限元软件对结构模型进行分析,得到不同载荷下的应变规律;最后,将有限元计算结果与试验结果进行对比,轴向刚度误差为10.69%,测点应变值最大误差为12.88%,表明该方法可用于缠绕复合材料夹芯圆柱壳计算,为复合材料夹芯圆柱壳的设计应用提供指导。     

大型储罐穹顶网壳结构研究综述

随着储罐的大型化,其穹顶网壳结构也在朝着大跨度、轻质量、薄厚度方向发展.穹顶网壳结构作为储罐的重要组成部分,其结构稳定性对于储罐安全性具有重要意义,国内外学者对大型网壳结构进行了大量研究工作.结合目前网壳结构的研究热点,总结了穹顶网壳结构选型、初始几何缺陷模拟、单层网壳结构稳定性、储罐穹顶施工受力分析等方面的研究现状,并对后续网壳结构研究工作提出了建议.     

含孔复合材料层合板的结构参数对其屈曲性能的影响

利用ABAQUS软件,建立了含孔复合材料层合板的有限元模型,在层合板四边简支,承受轴向压力载荷作用下,分析讨论了孔径/板宽比、铺层比例、铺层角度、材料性能等结构参数对层合板的线性屈曲的影响。结果表明,孔径/板宽比d/w越大,屈曲载荷越小,当d/w≤0.1时,可认为是小孔洞情况,可近似按无限大层合板处理;90°铺层(与载荷受力方向一致)比例越大,或0°铺层(与载荷受力方向垂直)比例越小,屈曲载荷越大,增加±45°铺层比例,有利于降低层合板各向异性程度;对于斜交对称铺层的层合板,铺层角度对其屈曲载荷影响很大,最大值与最小值相差13.05N;材料主方向结构性能参数差别较大时,屈曲载荷也相差较大,材料的结构性能参数对屈曲承载力具有明显的影响。     

某型无人机机翼复合材料大梁迭代设计方法与有限元强度验证

根据工字梁腹板及缘条受力特点,计算了某型无人机机翼大梁在均布升力作用下腹板和缘条的内力。基于经典层合板理论和最大应力强度准则,采用Matlab软件编程,运用迭代法设计了机翼工字形层合结构大梁的铺层结构。建立了复合材料层合结构大梁的有限元模型,基于最大应力强度准则对大梁结构进行有限元强度校核,给出了各层的安全裕度。分析结果表明,基于经典层合板理论的迭代设计方法能够在有限次迭代后设计出符合要求的复合材料层合结构翼梁,层合结构翼梁各铺层安全裕度均大于0.5,该工字梁结构强度符合设计要求。     

复合材料层合板强度界限

本文提出了复合材料层合板强度上下限的概念，给出了层合板强度上下限的计算方法，并以复合材料单向板的强度准则的为基础，对一些特殊铺层的层合板在几种受力状态下的强度限进行了讨论。     

某胶囊型网壳大棚设计建造与比较优势分析*

胶囊型网壳储料大棚结构体系新颖，属于拱形与球壳的组合体，建成后外形美观。本文研究了胶囊型钢结构网壳的结构力学特性，该体系用钢量省，稳定性好。借助了BIM建模技术辅助建造实施，利用施工动画全面展示建造流程，既直观又高效。相同储料条件下，与圆柱形直立山墙网壳相比，在展开面积上有明显差别，用钢量有较大的优势。     

某胶囊型网壳大棚设计建造与比较优势分析*

我厂有2台φ3.8m×13.5m的二仓闭路水泥磨。该水泥磨采用中心传动方式,磨机的支撑部位在磨机本体的两端,滑履轴直接固定在磨机筒体上,然后由瓦座支撑。在水泥磨刚投产几年,磨出口滑履温度正常,但近2年来,尤其在炎热的夏季,常常因为     

大直径立式圆筒形储罐罐顶网壳的设计分析

石化行业的大型圆筒形储罐罐顶经常采用单层网壳作为支撑结构,根据目前已建工程的资料,此类钢网壳的最大直径已达到60m。由于根据现行规范对网壳的整体稳定计算实现起来比较繁琐,目前国内此类网壳结构在实际工程的设计方法参差不齐。本文将以实际工程为例,提出此类网壳的设计过程和方法,与读者进行探讨。     

大跨度石灰石球形堆棚施工过程与关键技术分析

基于大跨度螺栓球网壳安装难度大，施工工序复杂的特点，本文以一个100 m跨度的球形石灰石堆棚为例，结合球形网壳受力特点，提出从底圈开始，逐圈环形安装方法。根据球形网壳特点，共分为A~J共10个施工工序。根据施工工序，开展施工过程分析和施工关键基础的研究。施工工况下位移与应力均较小，且施工速度快，具有较大推广意义。在门洞位置的挠度和应力比均相对于其他位置较大，门洞位置的杆件变形、结构挠度监控应为施工过程中重点关注区域。     

椰壳粉/PVC复合材料的结构及动态力学性能研究

将改性椰壳粉填充到聚氯乙烯(PVC)中制得椰壳粉/PVC复合材料,用SEM、DMA对复合材料的结构和动态力学性能进行了研究。结果表明:改性后的椰壳粉与基体PVC的界面黏结强度提高;用2.0%硅烷偶联剂KH-550及15%HDPE-g-(GMA-co-St)改性后,复合材料具有较好的动态力学性能。     

Mechanical strengths of epoxy resin composites reinforced by calcined pearl shell powders

A series of epoxy resin (EP) composites were prepared using ground pearl shell powders, which had been calcined at various temperatures. The EP composite containing ～ 3% weight content of the calcined pearl shell powder had the highest impact strength and the presence of silane agent was found to be essential for the composite formulation. The impact strengths of the resultant EP composites were highly influenced by the specific surface area, surface morphological structure, and chemical composition of the calcined pearl shell powder. The highest mechanical improvement was obtained for the EP composite prepared with the pearl shell powder calcined at 700°C for 3 h. The layered biopolymeric materials were completely degraded for the pearl shell powder calcined at 700°C, resulting in “sponge‐like” or “net‐like” porous calcium carbonate powder. However, the degradation of the layered biopolymeric materials was not complete for the calcinations at lower temperatures (<600°C), while calcium carbonate decomposed to form calcium oxide at higher temperatures (>800°C). The mechanical improvements of the processed EP composites have been discussed along with the chemical compositions and surface microstructures of the incorporated pearl shell powders. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effects of shell powder size and content on the properties of polycaprolactone composites

In this work, the effects of particle size and content of clam shell powder (CSP) on the mechanical properties and microstructure of clam shell powder-polycaprolactone (CSP-PCL) composites were studied. Accordingly, shell powder with particle size of 50, 100, 200, and 400 meshes, and CSP content of 30, 40, 50, and 60 wt%, respectively, were utilized to prepare CSP-PCL composites. The interface structure and properties of CSP-PCL composites were investigated by infrared spectroscopy (IR), X-Ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry, thermogravimetric analysis (TGA), and tensile tests. The results showed that the tensile properties of the composite materials correlated with the particle size and content of the filler. For instance, the smaller the particle size of CSP (400 meshes), the better the tensile properties of the composite. What is more, the tensile properties of the composites were negatively affected by the amount of CSP content. In terms of microstructure, shell powder particles could disperse uniformly in the PCL matrix, and the CSP-PCL composites with polyurethane prepolymer as compatibilizer gave a better compatibility.     

核壳结构材料表征技术

本文对核壳结构共聚物进行了剖析，介绍了一些最常用的核壳结构表征技术．以大量文献为基础并结合笔者的经验．详细地阐述了这些表征技术的原理、方法、特点、局限性及改进方法，并结合核壳结构材料的应用，展望了核壳结构表征技术的发展趋势。     

Fire‐retardant plastic material from oyster‐shell powder and recycled polyethylene

A series of plastic materials from recycled polyethylene (PE) and oyster‐shell powder were prepared to test their fire‐retardant properties with an aim of finding a practical way of waste recycling. Oyster‐shell powder was found to be mainly composed of calcium carbonate and it decomposed to calcium oxide and carbon dioxide at temperature higher than ～800°C, thus preventing fire from access of oxygen by the produced carbon dioxide. This fire‐retardation mechanism is environmental‐friendly, since another available method, the inclusion of halogen‐containing compounds, normally generates toxic chemicals like dioxine during incineration. To improve mechanical properties of this composite material, surface of oyster‐shell powder was coated with cetyltrimethylammonium bromide (CTAB). Flame retardation and the mechanical properties of these composite resins were analyzed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1583–1589, 2006