隔板方向对泡沫芯复材夹芯梁抗剪性能影响的试验研究

EXPERIMENTAL STUDY ON BULKHEAD'S DIRECTIONAL EFFECT OF REINFORCED FOAM CORE COMPOSITES SANDWICH STRUCTURES

采用真空导入工艺制作了3组不同方向(横向、纵向及双向)的隔板增强泡沫芯复材夹芯梁,对其进行了剪跨比为3的三点弯试验研究,获得了其失效过程及破坏模式,分析了隔板布置方向对该复材夹芯梁受剪力学行为的影响。结果表明:1隔板横向、纵向及双向布置时,夹芯梁的破坏模式分别为上面层弯曲折断、侧面层局部屈曲及上面层剪切破坏;2横向隔板可有效阻止泡沫芯材的斜裂缝扩展,从而提高构件在横向荷载作用下的延性,但不能显著提高夹芯梁的刚度和强度;3隔板纵向布置时,构件的承载力和刚度相比于未增强的普通泡沫芯复材夹芯梁分别提高了1.02倍及5.65倍,但延性仅提高了0.23倍;4双向隔板增强泡沫夹芯梁的力学性能与纵向隔板增强泡沫夹芯梁较为相似,其承载力和刚度均明显高于横向隔板。

In order to analyze the directional influences on failure mode and mechanical behavior of diaphragm reinforced foam core sandwich beams caused by bulkhead＇ s arrangement direction,three point bending tests were conducted on 3 sandwich beams,which were made through vacuum infusion process including unidirectional reinforcement and bidirectional enhancements. The results show that the failure modes of sandwich beams reinforced by transversal,longitudinal and bidirectional bulkhead were top panel＇s bending broken,lateral panel＇s local buckling and top panel＇s local shearing failure,respectively. The ductility of beams under lateral load was improved due to the reasons that inclined cracks propagation was prevented by transversal bulkhead. Compared with the unreinforced sandwich,the capacity and elastics modulus of sandwich beams strengthened by longitudinal bulkheads were increased by 1. 02 and 5. 65 times,respectively,while the ductility changes into 1. 23 multiples of the original. Mechanical behaviors of specimens that were reinforced by longitudinal and bidirectional bulkhead are similar,and their carrying capacity and elastic modulus were superior to those reinforced by transversal bulkheads.