This work proposes a novel and robust thermal imaging-based method suitable to quantify damage evolution stages in fibre-reinforced composite materials under fatigue loading. The method uses adiabatic hysteretic heating of the material to calculate the change of enthalpy by thermal imaging when the material undergoes fatigue damage. This work analytically corroborates the validity of using the calculated change of enthalpy to identify the three different fundamental fatigue damage stages of the material. The method is applied to two different types of notched sandwich specimens subject to constant amplitude fatigue loading. It is practically demonstrated that the characteristic curve progressions of the mechanically measured hysteretic dissipation curves are in good agreement with those of the enthalpy change computed by the proposed method.

这项工作提出了一种新颖而强大的基于热成像的方法，适用于量化疲劳载荷下纤维增强复合材料的损伤演化阶段。该方法利用材料的绝热滞后加热，通过热成像来计算材料在遭受疲劳损伤时的焓变。这项工作在分析上证实了使用计算出的焓变来确定材料的三个不同的基本疲劳损伤阶段的有效性。该方法适用于承受恒定振幅疲劳载荷的两种不同类型的缺口夹心样品。实践证明，机械测得的磁滞耗散曲线的特征曲线与拟议方法计算出的焓变曲线具有良好的一致性。