树脂基复合材料RTM工艺的研究进展

RTM工艺是一种复合材料液体模塑成型技术,目前已在诸多领域获得广泛应用。采用RTM工艺成型树脂基复合材料的过程中,合理的模具设计可保证产品的质量和精度,树脂基体的设计及改性直接影响到产品的力学性能,成型工艺参数的设定可提高生产效率并减少不合格品率,计算机辅助设计可有效模拟成型过程并对制品结构的力学性能进行预判,减少不合理设计造成的浪费和污染,上述各研究方向均对RTM工艺制品的性能有较大影响,并已开展了大量的研究工作,本文对上述研究方向进行综述。     

高性能复合材料树脂传递膜技术(RTM)研究

树脂传递模塑法（RTM）是一种低成本、效益好的复合材料成型工艺。研究了RTM用树脂体系、预成型技术、成型模具、成型工艺以及RTM在航空航天领域的应用。     

复合材料RTM模具的制备

根据树脂传递模塑(RTM)模具对基体树脂的基本要求,选用双酚A环氧乙烯基酯树脂为基体,聚乙酸乙烯酯为低收缩添加剂,玻璃纤维经编织物为增强材料,并加入相应的助剂,制备了复合材料RTM模具。该模具具有成本较低、开发周期短、精度较高等优点,但表面强度和热效率较低。     

先进树脂基复合材料RTM工艺的研究进展

随着复合材料的应用越来越广泛,制件产品复杂性和质量要求越来越高,逐渐衍生出多种复合材料成型工艺.而树脂传递模型(RTM)及其派生工艺是一种高质量、高精度、高效率、低成本和绿色化的闭模成型工艺.本文简要介绍了RTM成型工艺原理、RTM衍生工艺成型过程及特点、RTM工艺应用现状以及RTM用树脂的研究现状,并提出了RTM工艺...     

RTM用不饱和聚酯树脂的发展概况

综述了RTM专用树脂的国内外发展概况 ,分析了国内RTM专用树脂存在的主要问题及其发展方向     

复合材料RTM成型工艺综述

本文主要是综述RTM成型工艺的基本原理、工艺特点,讨论了适于RTM的增强材料和树脂休系并讨论了工艺参数对RTM模制品质量的影响以及RTM在成型三维复合材料方面的应用。     

先进树脂基复合材料RTM成型工艺研究及应用进展

复合材料的成型工艺是改进并提升先进树脂基复合材料性能的关键,而树脂传递模塑(RTM)成型工艺是一种环保高效、成本低、高精度的闭模成型工艺。概述并分析了传统RTM成型工艺过程及优缺点,并对高压树脂传递模塑成型(HPRTM)、轻质树脂传递模塑成型(LRTM)、真空辅助树脂灌注工艺(VARTM)、西门(Seeman)树脂浸渍技术(SCRIM P)等RTM衍生成型工艺的研究进展与应用进行了介绍分析。     

RTM用BMI树脂的研究

本文介绍RTM用的双马来酰亚胺(BMI)树脂体系,它主要由BMI、二烯丙基双酚A、苯乙烯和其它助剂所组成。此树脂体系在常温下粘度低,贮存稳定性好,反应性优良,能满足RTM的工艺要求,其固化树脂和复合材料层压板具有良好的力学性能和耐热性。     

RTM用不饱和聚酯树脂的发展概况

综述了RTM专用树脂的国内外发展概况，分析了国内RTM专用树脂存在的主要问题及其发展方向。     

一种适合于树脂传递模塑成型工艺的树脂基体及其碳纤维复合材料性能

选用一种液体改性芳香胺为环氧树脂的固化剂,得到了一种适合于树脂传递模塑(RTM)的高性能树脂体系。实验研究表明,该树脂体系在100℃时粘度仅为0.01Pa.s,在40℃时适用期在8h以上,Tg为107℃;其碳纤维复合材料抗剪切强度70MPa,抗拉强度1020MPa,抗张模量98GPa。说明该树脂体系粘度低,适用期长,玻璃化温度较高,与碳纤维的浸润粘接性好,可用作RTM成型工艺的高性能树脂基体。     

A process performance index and its application to optimization of the rtm process

Resin transfer molding (RTM) is a promising manufacturing process for hig formance composite materials. However, the fact that RTM process design has traditionally been an expensive, time‐consuming trial‐and‐error procedure has p ited its wide application base. This paper proposes a solution to that problem—a simulation‐based optimum process design scheme for RTM. This scheme ei engineers to determine the optimum locations of injection gates and vents so both process efficiency and high part quality can be ensured. Essential to this mum process design scheme is a process performance index, which is defined respect to the major factors influencing RTM process efficiency and part quality This index is then used as the objective function for the RTM process design optimization model. Gate and vent locations are the process design parameters optimized. All data is obtained by running an RTM simulation program, and th netic algorithm (GA) is employed to carry out the optimization procedure for design parameters. It is found that constant pressure optimization will yi process with a short flow path, whereas constant flow optimization will yield process with smooth and vent‐oriented flow pattern. Although there is no dry factor in the objective function, it is interesting to note that both constant pres and constant flow optimization procedures result in process designs with a mil mum probability of dry spot formation. This study finds that, in general, cons flow optimization should be employed if injection pressure is not a major cone otherwise, constant pressure optimization should be used. Two case studies presented to illustrate the efficacy of this approach.     

RTM注射成型列车机车用复合材料车门/窗框

本文介绍了一种采用RTM注射成型的列车机车用聚合物复合材料车门框和车窗框的模具设计、材料选择、模具和产品制备过程以及制品性能检测和应用结果。结果表明，本文所研制的聚合物复合材料车门／窗框的模具设计、材料选择合理，模具和产品制备工艺符合列车机车用车门／窗框的性能要求，制品性能经检测符合技术标准，经实际应用考核可知，该工艺完全能满足列车机车用复合材料车门／窗框制备的需要。     

Optimization method to reduce three-dimensional thermal gradients in resin transfer molding

Presently, the mold and resin are heated to promote resin flow and shorten curing period in order to improve manufacturing efficiency of resin transfer molding (RTM). This nonisothermal manufacturing process easily generates three-dimensional thermal gradients in the direction of resin flow and thickness of composite part. However, the existing heating systems only consider the thermal gradients along thickness direction. The thermal gradients in direction of resin flow cannot be reduced which will lead to residual stress even deformation and cracking in composite part. This article aims at reducing the three-dimensional thermal gradients in the direction of resin flow and thickness of composite part. Based on the theory of energy and fluid flow, an optimization method of heating system design by using numerical simulation is proposed. The results show this method reduces the three-dimensional thermal gradients effectively in composite part manufactured by RTM process. This study can provide powerful tools for heating system design to manufacture composites products in polymer industry. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48948.     

复合材料工型肋的RTM工艺模拟与优化

采用PAM-RTM模拟软件,对变截面工型肋结构零件进行RTM工艺注射方案设计。过程中,分别进行了6种注射方案的结果模拟,从注射方式、注射参数及注射口选择等方面进行方案设计,对注射过程中的压力分布、树脂浸润效果及注射时间进行比较,根据比较结果进行综合评定,最终得出了最优注射方案,并将结果用以指导工装设计,成型了验证零件。结果表明:采用计算模拟技术,可替代人工试验,进行工艺及工装方案设计与制造;工型肋的摆放位置对树脂的浸润趋势和注射时间影响较小,但注射口和注射方式选择对工型肋零件的影响很大,线注射方式及端部注射的浸润效果和效率要好于点注射及梢部注射。     

An RTM densification method of manufacturing carbon-carbon composites using Primaset PT-30 resin

This paper presents a development of carbon-carbon (C-C) composite by resin transfer molding (RTM) process. The RTM was used for both manufacturing of the resin matrix composite part as well as impregnation of the carbonized parts. Materials chosen were heat-treated T300 2-D carbon fabric and Primaset PT-30 cyanate ester. The PT-30 resin has a char yield similar to that of phenolics, very low volatiles, low viscosity at processing temperatures, and no by-products during cure, and hence, an excellent choice for RTM process. The process consists of RTM of the composite part, carbonization, RTM impregnation, and re-carbonization. The last two steps were repeated to achieve the desired density. The measured density and mechanical properties of just two times-densified C-C composite panels were superior to or nearly the same as the data in the literature by other processes. The RTM densification is about twice as fast as the resin solution method and it is environment friendly.     

Optimization method to select temperature based on chemorheological and exothermal reaction of RTM

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.     

液体树脂灌注成型技术（LRI）的数值建模计算研究

近几年在树脂膜渗透成型工艺（RFI）的基础上开发出了一种新型的航空复合材料制造工艺：液体树脂灌注成型工艺（LRI,Liquid Resin Infusion）。由于LRI是在一个真空膜下进行的,它不需要特殊的模具,所以大大降低了制造成本,并且用这种工艺可以制出大而厚的复杂部件,但是这也使得我们很难了解到整个工艺过程中内部参数的变化情况。为了指导实际的制造工艺,优化制造方案和参数,并减少制造缺陷,开发和运用有效的数值计算模型就变的非常的必要。最近Celle等人利用有限元方法（FEM）开发出了一种有关LRI的基础数值模型,本文将要介绍在这种基础模型上开发出的对LRI的数值建模计算方法和它的应用。并与实验结果进行对比和讨论。结果表明：本文所做的数值建模计算结果与实验结果有着较好的一致性,能较为有效地对LRI成型工艺进行模拟计算。关键词树脂传递模塑（RTM）;树脂膜渗透（RFI）;液体树脂灌注成型（LRI）;有限元方法（FEM）;数值建模     

Resin transfer molding process optimization using numerical simulation and design of experiments approach

The art of resin transfer molding (RTM) process optimization requires a clear understanding of how the process performance is affected by variations in some important process parameters. In this paper, maximum pressure and mold filling time of the RTM process are considered as characteristics of the process performance to evaluate the process design. The five process parameters taken into consideration are flow rate, fiber volume fraction, number of gates, gate location, and number of vents. An integrated methodology was proposed to investigate the effects of process prameters on maximum pressure and mold filling time and to find the optimum processing conditions. The method combines numerical simulation and design of experiments (DOE) approach and is applied to process design for a cylindrical composite part. Using RTM simulation, a series of numerical experiments were conducted to predict maximum pressure and mold filling time of the RTM process. A half‐fractional factorial design was conducted to identify the significant factors in the RTM process. Furthermore, the empirical models and sensitivity coefficients for maximum pressure and mold filling time were developed. Comparatively close agreements were found among the empirical approximations, numerical simulations, and actual experiments. These results were further utilized to find the optimal processing conditions for the example part.     

耐压夹芯复合板制备工艺

介绍了一种耐压夹芯复合板的穿纱及树脂传递模塑(RTM)制备方法,选用橡胶为芯材,复合材料为蒙皮,通过RTM成型方法制备,研究了穿纱工艺及RTM工艺参数对制品的影响。结果表明,通过穿纱增强的RTM成型制品不仅表观质量良好,且具有优异的界面粘结性能,实现了承载吸声结构功能一体化设计,适用于深水压力环境。