The adhesives used for the attachment of electronic components to space boards should withstand harsh vibrations of the space launch, which requires their characterization in fatigue. The present study investigates Ablestik 8-2 epoxy adhesive within this context. Novel adhesive test assemblies were devised, which consist of a rigid ceramic component bonded to a resonant flexible epoxy-fibreglass (E-glass) support. Cantilever and square E-glass supports produced uniaxial and biaxial bending, respectively. The in-situ fatigue tests, conducted on batches of uniaxial/biaxial bending adhesive assemblies, led to distinct data sets of maximum support deflection versus the number of cycles to crack initiation/total failure. The derivation of an intrinsic fatigue damage law of the adhesive relied on the substitution of deflection by the maximum principal strain of each adhesive point while keeping the Basquin’s form. In so doing, the adhesive strain was computed from finite element models of test assemblies built and simulated under Abaqus. The adhesive layer was meshed by cohesive elements created through a Fortran user-element subroutine coupled to Abaqus. The subroutine incorporated an already validated static damage together with the strain-based fatigue damage law sought. The retained Basquin’s fatigue damage law has undergone calibration against uniaxial bending test data and validation by biaxial bending test data.

用于将电子组件连接到空间板上的粘合剂应承受航天器发射的剧烈振动，这需要对其疲劳进行表征。本研究在此背景下研究了Ablestik 8-2环氧胶粘剂。设计了新颖的粘合剂测试组件，该组件包括与共振柔性环氧玻璃纤维（E-glass）支架粘合的刚性陶瓷组件。悬臂和方形电子玻璃支架分别产生单轴和双轴弯曲。对一批单轴/双轴弯曲粘合剂组件进行的原位疲劳测试得出了最大支撑挠度与裂纹萌生/总破坏循环次数的不同数据集。胶粘剂的固有疲劳损伤定律的推导取决于挠曲被每个胶粘点的最大主应变所替代，同时保持了Basquin的形式。这样，可以根据在Abaqus下构建和模拟的测试组件的有限元模型来计算粘合应变。粘合剂层由通过耦合到Abaqus的Fortran用户元素子例程创建的粘合元素划分网格。该子例程结合了已经验证的静态损伤以及寻求的基于应变的疲劳损伤定律。保留的Basquin的疲劳损伤定律已针对单轴弯曲测试数据进行了校准，并通过双轴弯曲测试数据进行了验证。粘合应变是根据在Abaqus下建立并模拟的测试组件的有限元模型计算得出的。粘合剂层由通过耦合到Abaqus的Fortran用户元素子例程创建的粘合元素划分网格。该子例程结合了已经验证的静态损伤以及寻求的基于应变的疲劳损伤定律。保留的Basquin的疲劳损伤定律已针对单轴弯曲测试数据进行了校准，并通过双轴弯曲测试数据进行了验证。粘合应变是根据在Abaqus下建立并模拟的测试组件的有限元模型计算得出的。粘合层由通过耦合到Abaqus的Fortran用户元素子例程创建的粘合元素划分网格。该子例程结合了已经验证的静态损伤以及寻求的基于应变的疲劳损伤定律。保留的Basquin的疲劳损伤定律已针对单轴弯曲测试数据进行了校准，并通过双轴弯曲测试数据进行了验证。