【作者】 王桂英；

【导师】 曹军；

【作者基本信息】 东北林业大学 ， 机械设计及理论， 2013， 博士

【摘要】 高压玻璃钢管具有比强度高、比刚度高、耐高压、耐腐蚀、使用寿命长且易实现机械化、自动化等一系列优点,在石油、化工和海洋等领域得到越来越广泛的应用,其优异的力学性能和独特的内固化成型工艺一直受到极大的关注,如何实现高压玻璃钢管管体缠绕、固化和力学性能分析一体化是目前急待解决的问题。本文基于这一要求,完成了以下几方面的研究工作：首先,针对高压玻璃钢管体内加热式固化成型的特点,建立了高压玻璃钢管固化过程的二维有限元模型,采用了变性方法来构建导热系数矩阵,开发了有限元代码对高压玻璃钢管的固化过程进行了数值模拟,揭示了沿管体厚度方向的温度和固化度变化规律以及纤维体积比对固化温度产生的影响。数值模拟结果表明：该有限元模型能真实地反应高压玻璃钢管体的固化过程,为科学地制定固化工艺提供理论依据。其次,用微分几何理论推导出高压玻璃钢管体缠绕成型的非测地线缠绕轨迹、包角方程及绕丝头运动方程,用有限元分析软件ANSYS中的APDL参数化设计语言编制的程序可进行缠绕过程的动态仿真数值模拟,得到的数据可直接用于两轴数控缠绕机进行缠绕。在计算过程中,比较了经典的微分几何方法和工程中常用的平面假设理论得到的芯模中心转角的差异,结果表明：按微分几何得到的线型与测地线接近,能更好地发挥纤维的力学性能,该方法可大大提高高压玻璃钢管体的结构效率。第三,进行了三个部分的试验研究工作,(1)对4种不同纤维体积含量的单向板进行了纵向拉伸和压缩强度、纵向拉伸模量、横向拉伸和压缩强度、横向拉伸模量、泊松比、面内剪切强度和剪切模量等力学性能参数的测试,根据试验结果求取了各力学参数的回归方程；(2)对2种工作压力分别为8.6MPa和15.5MPa的高压玻璃钢管体进行了失效压力测试试验；(3)对高压玻璃钢管体的纤维体积含量进行了整体测试和分层测试,为高压玻璃钢管失效强度的数值预测及分析提供了充分的试验参考依据。最后,针对高压玻璃钢管体材料的力学性能分布不均匀的特点,根据蔡-吴(Tsai-wu)失效准则,采用常规失效分析方法和逐步失效分析方法,借助于通用有限元软件ANSYS的APDL参数化设计语言,编程模拟2种不同压力等级的管体层合板在加载过程中的失效强度并将预测结果同试验结果进行对比,结果表明：(1)高压玻璃钢管体的逐渐失效过程是由管体外层向内层逐层进行的,内层的富树脂层相当于弹性体,可产生比较大的变形量,能承受更大的内压力；(2)常规失效分析,由于只考虑了管体最内层失效的压力,忽视了其它各层失效后的剩余刚度,其预测值均低于实测失效压力的平均值,8.6MPa管体和15.5MPa管体预测误差分别为为5.5%和6.5%,偏于保守。(3)逐渐失效分析则充分考虑了各层板失效后的剩余刚度,其预测值高于实测失效压力的平均值,8.6MPa管体和15.5MPa管体预测误差分别为2.9%和2.0%,更为合理。(4)高压玻璃钢管体层板的最终失效不是由纤维断裂导致的,而是由于树脂基体的失效引起的,这一点充分说明了高压玻璃钢管的内固化工艺在管体内表面形成的富树脂层大大提高管体的承载能力。本项目的研究,不仅为高压玻璃钢管管体的缠绕、固化和力学性能的设计和分析提供理论依据和试验基础,同时也为其它玻璃纤维/环氧复合材料制品的设计和制造提供宝贵的资料,具有很大的实用参考价值。更多还原

【Abstract】 High pressure FRP pipe has many advantages, such as high specific strength and stiffness, high pressure resistance, long service life and can be produced in mechanical and automatic way. It has been widely used in oil field, chemical industry and ocean field. It has been paid more and more attention for its excellent mechanical performance and special internal curing process. An urgent problem is how to integrate the winding, curing and mechanical performance analysis of high pressure FRP pipe. For this reason, the following research work has been done:First, the2D finite element model has been made for the internal curing process of high pressure FRP pipe. The heat conduction coefficient matrix has been set with variance method. The finite element code has been developed to simulate the curing process of high FRP pipe. The temperature and curing degree variation along the pipe wall and the effect of fiber volume ratio on the temperature is revealed. The result shows that the finite element model can describe the curing process of high pressure FRP pipe and can be used as the theoretical basis of the curing process.Secondly, the differential geometry is used to derive the non-geodesic trajectory, envelope equation and feeding-eye equation. The APDL parametric design language is used to simulate dynamically the winding process. The data can be used in the two-axis numerical control filament winding machine. The calculation result derived from the plane assumption and differential geometry is compared. The result show that the result from the differential geometry is close to that of geodesic theory and it can make the fiber mechanics best. The structure efficiency of the high pressure FRP pipe is greatly improved.Thirdly, three kinds of test has been done.(1) The longitudinal tensile and compressive strength, longitudinal tensile modulus, transverse tensile and compressive strength, transverse tensile modulus, poisson ratio, in-plane shear strength and modulus is tested for four kinds of laminas of different fiber volume ratio. The regression equation of the mechanical performance is given.(2) The failure pressure is tested for8.8MPa and15.5MPa pipe body.(3) The fiber volume ratio for the whole and each layer is tested for the theoretical analysis and strength prediction of high pressure FRP pipe.Finally, for the uneven distribution of mechanical performance of high FRP pipe, with the Tsai-wu failure criteria, the traditional failure analysis and progressive analysis and APDL parametric language of ANSYS software, the failure strength is simulated for2kinds of pipe bodies and is compared with the tested strength. The result shows that (1) The progressive failure process of the high pressure FRP pipe is from external layer to internal layer. The internal resin rich layer is like elastomer and it can stand large deformation and internal pressure.(2) In the traditional failure analysis, only the failure pressure in the internal layer is taken into account and the residual strength of other failure layers is omitted. The prediction pressure is lower than the tested pressure and the prediction error is5.5%for8.6MPa pipe and6.5%for15.5MPa pipe. The traditional prediction analysis is conservative.(3) The residual strength is taken into account in the progressive prediction analysis. The prediction pressure is higher than the tested pressure and the prediction error is2.9%for8.6MPa pipe and2.0%for15.5MPa pipe. The progressive prediction analysis is more reasonable.(4) The final laminate failure of the high pressure FRP pipe is not caused by the fiber fracture instead of the resin failure. This means that the resin rich layer of the internal surface by the internal curing process of high pressure FRP pipe improves the load capacity greatly.This research work provides not only the theoretical evidence and testing basis for the winding, curing and the design and analysis of mechanical performance of high pressure FRP pipe, but also the precious information for the design and manufacturing of other glass fiber/epoxy composites.更多还原