泡沫铝夹芯梁结构的高温3点弯曲力学性能研究

实验研究了泡沫铝夹芯梁结构在不同温度下的3点弯曲力学性能.通过引入Gibson模型构建夹芯梁架构在3点弯曲作用下的失效模式图，并将失效模式图扩展到高温情况下，得到泡沫铝夹芯梁的初始失效模式图随温度的变化趋势.结果发现，其他因素不变，随着温度的升高，夹芯梁结构更容易发生面板屈服失效模式，芯层剪切模式涉及的范围被大大压缩.根据修正的Gibson模型预测的夹芯梁结构的极限载荷和实验结果所得极限载荷比较发现，芯层剪切模式分析结果和实验数据很好地吻合，说明泡沫铝夹芯梁的最终失效破坏主要是由于芯层剪切引起的.

Three-Point Bending Responses of Aluminum Foam Core Sandwich Beams at Elevated Temperatures

Quasi-static three-point bending tests at different temperatures were carried out for sandwich beams with aluminum face sheets and closed-cell aluminum foam core. Failure mechanism maps which illustrate the dominant initial failure mode for practical beam designs were constructed for different test temperatures based on the modified Gibson model. It was found that upon increasing the temperature, face yield mode tends to occur but the tendency of core shear mode decreases. The theoretical predictions of the initial failure modes and limit loads according to the modified Gibson model are found to be in good agreement with the experimental results at different temperatures. It is showed that the failure of aluminum foam sandwich beam is mainly caused by shear of core layer.