共查询到20条相似文献,搜索用时 140 毫秒
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对VARI制备高长径比复合材料过程中的树脂流动行为进行模拟与实验研究,利用PAM-RTM软件模拟树脂流动过程,讨论了各工艺参数对树脂流动的影响,并通过实验测试对模拟结果进行了验证与比较。研究表明,纤维增强体孔隙率越大、注射压力越大和树脂粘度越低,树脂的填充速度越快。在模具直径φ4 mm、注射压力0.3 MPa、树脂粘度≤0.9Pa˙s和纤维体积分数≤60%的情况下,可以实现较长试件的快速注射,所需注胶时间最高不超过2 h。 相似文献
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在复合材料液体成型工艺过程中,通过计算机软件对成型工艺进行模拟研究,有助于优化模具设计和工艺参数。相较于将传统的二维织物,树脂在三维增强预制体中的流动更复杂,特别对于大尺寸、大曲率结构件,工艺仿真模拟则十分重要。通过计算机辅助模拟可以预测复合材料液体成型工艺过程中树脂的流动时间以及流动形式,进而指导工艺中的流道设计。针对三维机织复合材料机匣结构件的工艺参数对RTM成型过程进行了模拟和分析。根据模拟结果选择合理的注塑方式和工艺参数,以支撑三维机织复合材料机匣的模具设计和成型工艺参数优化。 相似文献
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利用Moldflow软件对电子镇流器底壳注射成型过程中最佳浇口位置和流动情况进行分析,确定了最佳浇口位置。通过对填充时间、气穴、熔接痕、锁模力曲线和流动前沿温度等数值模拟,预测塑件可能出现的缺陷,显示了Moldflow技术在模具开发过程中对于优化塑料注射模设计和优化注射工艺参数等方面所起到的显著作用。 相似文献
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主要介绍了RTM工艺树脂充模过程的流动模式、充模过程模拟的流动模型和模拟方法。讨论了不同模拟情况下所需的合理假设、边界条件的设置以及采用的不同数值计算方法。同时,介绍了目前基于数值计算的RTM仿真软件,提出了RTM充模仿真研究的未来发展趋势。 相似文献
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吴飞 《高科技纤维与应用》2011,36(2):39-43
综述了真空辅助树脂转移模塑(VARTM)工艺的树脂体系、工艺过程研究与模拟等的研究进展.表明环氧树脂是VARTM成型工艺的重要树脂基体,双马树脂作为一个重要的基体材料,目前基本处在研究阶段;工艺过程的试验研究和数值模拟发展迅速,国外借助先进技术手段,采用数值模拟方法等对工艺过程进行优化和控制的研究日趋活跃;在航空、船舶... 相似文献
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复合材料热压罐固化工艺中,构件的脱模变形是影响成型质量的重要原因。通过热电偶和光纤光栅传感器相结合的方法对复合材料构件在热压罐成型工艺过程中的温度和应变进行了在线监测,研究了模具构件的相互作用导致的应变发展,并分析了树脂固化对模具构件相互作用的影响。结果表明:固化过程初期,应变主要来自构件压实和树脂的流动、凝胶,而后模具构件的相互作用会随树脂固化度的增大而增大,模具与构件之间转变为粘接状态,降温时模具构件的相互作用会使二者发生分离导致构件发生应力释放,并且应力释放会使模具构件的相互作用减弱。 相似文献
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为解决复杂复合材料构件的整体一次成型问题,提高复合材料制品的整体性能,降低生产成本,本文采用硅橡胶制备软模,利用其柔韧性解决常规模具无法一次成型的问题。并通过软模/真空灌注工艺制备了带复杂孔圆盘,以验证其工艺可行性。通过比较与其他工艺制备的复合材料性能,探讨其使用前景。结果表明,采用软模/真空灌注工艺可一次整体成型带复杂孔圆盘等复杂构件,制品性能稳定。 相似文献
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Yoshihito Kondo Yutaka Hashizuka Shojiro Okada Kozo Ishizaki 《Journal of Porous Materials》1995,1(1):69-74
Although a slip cast process using a gypsum mold enables large and complicated dense green body to be made, the green body is contaminated with calcium and sulfur impurities from the gypsum mold. In the case of a resin mold, external pressure must be applied due to its poor water wettability. Porous alumina ceramics are used as a mold material for the first time to overcome these problems. The porous alumina ceramics show higher water wettability than gypsum or resin. The porous alumina molds have submicron pores, and provide larger penetration pressure and higher casting rate than gypsum molds. 相似文献
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Heating mold and resin have been widely used in resin transfer molding (RTM) to improve injection and manufacturing efficiency. The unreasonable mold/resin temperatures sometimes lead to excessive viscosity of resin and premature curing, which will result in failure of the filling process. Selection of optimal mold and resin temperature has become a source of concern in the polymer industry. This article presents an optimization method to select mold and injection resin temperatures by using numerical simulation based on chemorheological and exothermal reaction of the RTM process. The results show that the optimization method has high computational efficiency for three-dimensional parts with different shapes. The selected mold/resin temperature ensures the smooth filling process, which provides a powerful tool for parameter design in polymer industry. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48245. 相似文献
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The curing step in resin transfer molding process involves heat transfer coupled with the curing reaction of thermoset resin. In order to examine the curing behavior under a specified cure cycle in the resin transfer molding process, numerical simulations are carried out by three-dimensional finite elements method. An experimental study for isothermal cure kinetics of epoxy resin is conducted by using differential scanning calorimetry. Kinetic parameters based on the modified Kamal model are determined from the calorimetric data for the epoxy system, and by using these parameters, numerical simulations are performed for a hat-shaped mold. It is found from the simulation results that the temperature profile and the degree of cure are well predicted for the region inside the mold. This numerical study can provide a systematic tool in the curing process to find an optimum cure cycle and a uniform distribution of the degree of cure. 相似文献
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环氧树脂成型工艺是很关键的.尤其是模具结构,在有关绝缘件方面的产品对其要求甚为显著;本文主要介绍了聚四氟乙烯(又称塑料王)在模具结构设计中的应用,包括模具浇口工艺,嵌件密封技术以及嵌件固定结构三个方面介绍。 相似文献
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通过对相机手柄座结构特点的分析,设计了相机手柄座注射模,介绍了该模具的工作过程。采用推管和大推杆联合脱模机构保证塑料件的脱模;在大推杆中开设隔片式冷却水道加强型芯镶件的冷却;同时解决了哈夫滑块与推管的干涉问题。实践证明,该注射模动作准确、可靠,生产的塑料件质量良好,能够满足用户的要求。 相似文献
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In general, a numerical scheme is a widely accepted technique for estimating resin flow in the liquid molding process. A numerical mold filling analysis is essential to optimize the manufacturing process of a composite. However, finding an optimal condition from the numerical analysis requires many numerical calculations. The efforts can be greatly reduced if a similarity solution replaces the repeated numerical calculations. In this study, similarity relations are proposed to predict the flow‐induced process variables. such as resin pressure, resin velocity, and flow front evolution time, during mold filling. Numerical simulations are performed for two cases where a material property, an injection condition or a part shape is different. The model is verified by applying the similarity relation for two numerical results obtained from the thin shell structure. 相似文献