| 引用本文: | 贾近,姜明,肖海英,张东兴.高低温交变湿热环境下外加载荷对不同孔隙率CFRP拉伸力学性能影响[J].哈尔滨工业大学学报,2019,51(5):23.DOI:10.11918/j.issn.0367-6234.201712127 |
| JIA Jin,JIANG Ming,XIAO Haiying,ZHANG Dongxing.Influence of external loading on tensile mechanical properties of CFRP with different porosity under high and low temperature alternating humidity-heat environment[J].Journal of Harbin Institute of Technology,2019,51(5):23.DOI:10.11918/j.issn.0367-6234.201712127 |
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| 高低温交变湿热环境下外加载荷对不同孔隙率CFRP拉伸力学性能影响 |
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贾近1,姜明2,肖海英1,张东兴1
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(1.哈尔滨工业大学 材料科学与工程学院, 哈尔滨150001; 2.上海复合材料科技有限公司, 上海 201112)
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| 摘要: |
| 通过高低温交变加速湿热循环试验及有限元模拟,研究了孔隙率和外加载荷对CFRP层合板湿热拉伸力学性能及界面破坏机理的影响. 通过控制模压压力,制备出3种孔隙率的层合板；加载载荷分别为层合板最大弯曲载荷的30%、40%和60%. 结果表明,孔隙率的增大是导致CFRP层合板湿热老化后拉伸性能大幅下降的主要原因,孔隙率越大,湿热拉伸强度下降越多. 外加载荷能加速纤维与树脂基体界面脱粘,使材料湿热拉伸性能进一步下降,而且对不同孔隙率的层合板影响程度不一样,其中影响最大的是孔隙率为0.08的层合板,其次是孔隙率0.04的层合板,影响最小的是孔隙率为0.11的层合板. 并且载荷越大,影响也越大,但其对材料湿热拉伸性能的影响远不如孔隙率的影响大. 使用ABAQUS软件建立有限元模型,计算得到了层合板的各层拉伸应力分布,结果发现湿热循环导致90°层承受的拉伸应力上升,因此容易发生基体开裂及纤维/基体界面脱粘,导致力学性能下降,这一结果与试验结果相一致. 计算得到的拉伸力学强度变化趋势与试验结果相一致. |
| 关键词: CFRP 孔隙率 弯曲载荷 湿热环境 力学性能 |
| DOI：10.11918/j.issn.0367-6234.201712127 |
| 分类号:TB332 |
| 文献标识码:A |
| 基金项目:黑龙江省自然科学基金(E201311) |
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| Influence of external loading on tensile mechanical properties of CFRP with different porosity under high and low temperature alternating humidity-heat environment |
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JIA Jin1,JIANG Ming2,XIAO Haiying1,ZHANG Dongxing1
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(1.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; 2. Shanghai Composites Science &Technology CO., Ltd, Shanghai 201112, China）
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| Abstract: |
| The effects of porosity and external loading on hygrothermal tensile mechanical properties and interfacial failure mechanism of CFRP laminates were studied by high and low temperature alternating accelerated hygrothermal cyclical test and finite element simulation. 3 kinds of laminates with different porosities were prepared by controlling molding pressure. The load on specimen was 30%, 40% and 60% of the maximum bending load of laminates, respectively. The results showed that the increase of porosity was the main reason leading to the sharp decrease of tensile properties of CFRP laminates after hot-humid aging. The greater the porosity was, the more hygrothermal tensile strength decreased. The external load could accelerate the debonding of the interface between fibers and resin matrix, further degraded the hygrothermal tensile strength of the composites, and had different effects on the laminates with different porosity. Among of them, the most influential one was the laminate with porosity of 0.08, the second was the laminate with porosity of 0.04, and the least was the laminate with porosity of 0.11. And the greater the load, the greater the impact, but the influence of load on the hygrothermal tensile properties of the laminates was far less than that of the porosity. ABAQUS software was employed to simulate tensile properties of composite specimen. The tensile stress distribution of the laminates was investigated, and it was found that the tensile stress increased at 90 degree layer due to the hydrothermal cycle. Therefore, the matrix cracking and fiber/matrix interface debonding were prone to occur, resulting in the decrease of mechanical properties, which was consistent with the experimental results. The variation trend of tensile mechanical strength calculated by the ABAQUS software was consistent with the experimental results. Keywords: CFRP; porosity; bending load; hygrothermal environment; mechanical properties 〖FQ(+25mm。22,ZX-W〗收稿日期: 2017-12-20 基金项目: 黑龙江省自然科学基金（E201311） 作者简介: 张东兴(1961—),男,教授; 贾近（1976—）,女,高级工程师通信作者: 贾近,jiajin@hit.edu.cn 碳纤维增强聚合物基复合材料（简称CFRP）具有比重小、比强度高、比模量高、耐高温、抗疲劳及耐化学腐蚀性能好等优点而广泛应用于飞行器的主、次受力构件及特殊部位的功能件[1-3]. 飞行器用复合材料在运输、贮存、发射或飞行过程中要面临如温度、湿度、复杂的外载荷等特殊环境,这些环境因子以不同的机制作用于复合材料,造成其降质退化直至损坏变质[4-9]. 例如,在超音速飞机飞行时,所用的复合材料要承受长期的温度在-55~130℃与湿度在0~80%RH交变的环境,经历多次飞行循环结束后,飞机进入维修护理期,在超音速飞机整个飞行服役期间,复合材料处于温度与湿度交变的湿热循环中[10-13]. 并且,由于CFRP制备工艺的特殊性,通常会形成孔隙、夹杂、分层等制造缺陷,其中,孔隙是复合材料结构中最为常见的缺陷之一. 大量的研究表明,孔隙会使CFRP在服役期间,因湿热等环境因素而加速材料性能的退化[14-16]. 目前国内外大多数学者多采用水浸、湿热试验箱等简单的恒温恒湿加速试验方法研究复合材料的湿热性能,试验湿热环境没有真实体现飞行器实际服役环境,同时未考虑外载荷的影响,得到的试验结果在实际应用上具有很大的局限性[17-19]. 因此,本文以含孔隙的碳纤维增强环氧树脂基复合材料(CF/EP)层合板为研究对象,基于材料服役期间的吸湿状态和内应力状态,通过模拟超音速飞机服役环境的高低温交变加速湿热循环试验,并结合有限元分析方法,研究湿热交变环境下孔隙率和外加载荷对CFRP层合板拉伸力学性能及界面破坏机理的影响,为CFRP在先进飞机中的应用提供理论设计依据. 1试验 |
| Key words: CFRP porosity bending load hygrothermal environment mechanical properties 〖FQ(+25mm。22,ZX-W〗收稿日期: 2017-12-20 基金项目: 黑龙江省自然科学基金（E201311） 作者简介: 张东兴(1961—),男,教授 贾近（1976—）,女,高级工程师通信作者: 贾近,jiajin@hit.edu.cn |
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