Abstract The graphene platelets (GnPs)/epoxy flexible sensor with controllable sensitivity and linearity can be used to monitor the deformation and damage of composite structures. The sensitivity and linearity can be regulated by dispersing different content of GnPs in epoxy and the dispersion was better improved by optimizing ultrasonic time and the ball mill mixing process. The GnPs/epoxy mixture exhibited relatively low percolation threshold of 0.76 vol %. In this paper, GnPs/epoxy mixtures with GnPs loading of 0.84 vol.%, 1.05 vol % and 1.58 vol % were selected as damage detecting and strain sensor, and the characteristics of sensors were demonstrated via various mechanical tests. The monotonic tensile results suggest that there are three different linear change sensing stages, (1–0.2%), (0.2%–0.6%) and (0.6%–1.2%), the linear growth of the electrical response is softened while the linear tendency is enhanced due to increasing GnPs content, and it exhibits relatively high gauge factor of 11.81, 15.25 and 22.54 for 0.84 vol %, 3.63, 8.13, 11.46 for 1.05 vol % and 2.53, 3.77, 4.69 for 1.58 vol % in different sensing stages respectively. The sensor of 0.84 vol % is more reversibility than 1.05 vol % upon cyclic loading-unloading test. The GnPs/epoxy sensor show promising applications for the damage monitoring of structural composite in the field of aerospace.

中文翻译：

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GnPs/环氧树脂传感器的应变传感行为和复合材料在单调拉伸和循环变形下的健康监测

摘要 具有可控灵敏度和线性度的石墨烯薄片（GnPs）/环氧树脂柔性传感器可用于监测复合结构的变形和损伤。通过在环氧树脂中分散不同含量的GnPs可以调节灵敏度和线性度，并通过优化超声时间和球磨混合工艺更好地提高分散性。GnPs/环氧树脂混合物表现出相对较低的渗透阈值，为 0.76 vol%。在本文中，选择了 GnPs 负载量为 0.84 vol.%、1.05 vol % 和 1.58 vol % 的 GnPs/环氧树脂混合物作为损伤检测和应变传感器，并通过各种机械测试证明了传感器的特性。单调拉伸结果表明存在三个不同的线性变化传感阶段，(1–0.2%)、(0.2%–0.6%) 和 (0.6%–1.2%)，由于 GnPs 含量的增加，电响应的线性增长减弱，而线性趋势增强，并且表现出相对较高的应变系数，分别为 11.81、15.25 和 22.54，分别为 0.84 vol %、3.63、8.13、11.46 和 1.05 vol % 和 2.5。 , 3.77, 4.69 分别为 1.58 vol % 在不同的传感阶段。在循环加载-卸载测试中，0.84 vol % 的传感器比1.05 vol % 的传感器具有更高的可逆性。GnPs/环氧树脂传感器在航空航天领域的结构复合材料损伤监测中显示出有前景的应用。在循环加载-卸载测试中，0.84 vol % 的传感器比1.05 vol % 的传感器具有更高的可逆性。GnPs/环氧树脂传感器在航空航天领域的结构复合材料损伤监测中显示出有前景的应用。在循环加载-卸载测试中，0.84 vol % 的传感器比1.05 vol % 的传感器具有更高的可逆性。GnPs/环氧树脂传感器在航空航天领域的结构复合材料损伤监测中显示出有前景的应用。