格构腹板增强泡桐木夹芯复材板的弯曲性能试验

EXPERIMENTAL RESEARCH ON THE FLEXURAL PROPERTIES OF PAULOWNIA WOOD CORE COMPOSITE SANDWICH PANEL REINFORCED BY LATTICE WEBS

采用真空导入工艺,制备了格构腹板增强泡桐木夹芯复材板。对不同格构腹板厚度和不同腹板间距的试件进行四点弯曲试验,研究其破坏模式、跨中应变和跨中挠度情况。试验结果表明:增加腹板厚度能有效提高夹芯板的极限承载力,提高幅度随腹板厚度的增加而减小;减小格构腹板间距也能提高夹芯板的极限承载力,提高幅度随格构腹板间距的减小而减小。采用铁木辛柯梁理论,考虑弯曲和剪切变形的共同影响,推导出板材跨中挠度计算式;采用经典夹芯梁理论预估了试件的受弯极限承载力,挠度和承载力的理论值与实测值均吻合较好。

Paulownia wood core composite sandwich panels reinforced by lattice webs were manufactured by vacuum infusion molding process. The specimens with different spaces between adjoining webs and web thicknesses were experimentally studied by four-point bending test. The failure modes,the distribution of strain and the mid-span deflection could be analyzed. It was concluded that the ultimate bearing capacity could be improved by increasing web thickness,the rate of improving was reduced along with increasing web thickness; the ultimate bearing capacity could also be improved by reducing web distance,the rate of improving was reduced along with reducing web distance.Considering the effect of bending deformation and shear deformation,the deflection calculation formulation was obtained by Timoshenko theory,the results of theory and test were compared and fitted well. The ultimate bearing capacity of sandwich composites was studied by ordinary sandwich beam theory. The analysis results agreed well with test results.