This paper aims to investigate the effects on metal sandwich panels with different dimple core designs using four-point bending simulation under constant and variable amplitude loading. A core design with cavity and porosity in the body structure was found to reduce the panel structural integrity. This would lead to unstable bonding between the panels and initiate an early delamination process. Sandwich panels consisting of AR500 as the outer layer and magnesium alloy AZ31B as the core material were simulated using dimples of different diameters and depths; 5.0 / 2.5 mm, 6.0 / 3.0 mm, 7.0 / 3.5 mm and 8.0 / 4.0 mm, at a range of 50 % to 90 % of maximum strength, based on the lowest material strength for cyclic loading. The results indicate that the highest fatigue damage of 85 % occurred at the effective region of the dimple area, where force was applied to the panel. A hemispherical dimple core 6.0 mm in diameter and 3.0 mm in depth produced a reduction of failure at the effective zone of more than 85 % and the regression coefficient was over 0.89. This illustrates that a large dimple size was vulnerable to early delamination failure at the dimple region.

本文旨在研究在恒定和可变振幅载荷下使用四点弯曲模拟对具有不同凹坑芯设计的金属夹芯板的影响。发现在车身结构中具有空腔和孔隙率的核心设计会降低面板结构的完整性。这将导致面板之间的粘合不稳定并引发早期分层过程。以AR500为外层，以镁合金AZ31B为芯材的夹芯板，采用不同直径和深度的凹坑进行模拟；5.0 / 2.5 mm、6.0 / 3.0 mm、7.0 / 3.5 mm 和 8.0 / 4.0 mm，在最大强度的 50 % 至 90 % 范围内，基于循环载荷的最低材料强度。结果表明，85%的最高疲劳损伤发生在凹坑区域的有效区域，向面板施加力的位置。直径为 6.0 毫米、深度为 3.0 毫米的半球形凹坑芯在有效区域产生的失效减少超过 85%，回归系数超过 0.89。这说明大的凹坑尺寸容易在凹坑区域发生早期分层失败。