Electro-thermal influencing mechanism of carbon fiber/epoxy unidirectional laminated composites based on dielectric properties
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摘要: 采用复合材料电热试验机对碳纤维/环氧复合材料(CF/EP)单向板进行0.05~0.2 A·mm-2直流电流通电处理,每次通电1.5 h,同时对其电热作用下的表面温度场进行测量;分析电热作用后CF/EP试样的纵向体积电阻和介电性能变化;通过三点弯曲测试表征电热作用前后的弯曲性能。结果表明:试样的温度场随通电时间均呈现先迅速上升后稳态平衡的趋势。低于0.125 A·mm-2的电热作用使温度场分布均匀,纵向体积电阻降低以及介电性能提升;高于0.125 A·mm-2的电热作用使中间区域温度场高于两边区域,纵向体积电阻上升以及介电性能下降。介电常数和损耗角正切随测试频率增大而降低,交流电导率随频率增大先稳定后上升。受电热作用影响最大的损耗角正切可作为特征参量。弯曲性能测试表明,低于0.125 A·mm-2的电热作用使CF/EP试样的弯曲强度和弯曲模量最大提升11.8%和7.32%,而高于0.125 A·mm-2的电热作用使试样的弯曲强度和弯曲模量最大降低8.26%和6.52%。
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关键词:
- 碳纤维/环氧复合材料 /
- 电热作用 /
- 介电 /
- 界面 /
- 弯曲性能
Abstract: Direct currents (DC) ranged from 0.05 A·mm-2 to 0.2 A·mm-2 were subjected through carbon fiber/epoxy (CF/EP) unidirectional composites with a 1.5 h duration by the electro-thermal tester,meanwhile the tem-perature fields were measured on the surface of samples under different electro-thermal treatments.Changes in the longitudinal volume resistance and dielectric properties were analyzed respectively after electro-thermal treatments.In order to characterize the flexural property,the three-point flexure test was conducted before and after electro-thermal treatments.Preliminary experimental results show that temperature fields of all samples are rising rapidly with the duration before steady-state equilibrium.Treatments at less than 0.125 A·mm-2 lead to a uniform temperature field,and make the longitudinal volume resistance decrease and enhance dielectric properties.Treatments at more than 0.125 A·mm-2 come to a contrary result.The dielectric constant and loss tangent increase with the increment of test frequency,whereas the AC conductivity remains unchanged and then rises.The loss tangent affected mostly by electro-thermal treatments can be used as characteristic parameter of electro-thermal influence.The flexural property test demonstrates that treatments less than 0.125 A·mm-2 make flexural strength and modulus increase by 11.8% and 7.32% mostly,but they reduce by 8.26% and 6.52% maximally after treating more than 0.125 A·mm-2. -
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期刊类型引用(3)
1. 包永洁,黄成建,陈玉和,戴月萍. 碳纤维纸木质电热复合材料面层电热效果的纵向尺寸效应. 复合材料学报. 2020(12): 3214-3219 . 本站查看
2. 王志平,孙凌丰,路鹏程,李娜,王宏洋. 电热作用对碳纤维/树脂复合材料界面应力的影响. 复合材料学报. 2019(06): 1381-1388 . 本站查看
3. 张路平,杨晓凤,郑海康,王倩,蒙真真,武志红. 多孔Al_2O_3/SiC、MoSi_2/SiC复合材料的制备及吸波性能. 化工学报. 2019(11): 4478-4485 . 百度学术
其他类型引用(3)
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