基于数字散斑相关法的荻草胶合界面应变分布分析

The strain distribution analysis of silvergrass adhesives interface using digital speckle correlation method

荻草(Miscanthus sacchariflorus)作为一种天然的生物质材料在复合材料的应用方面具有很大潜力。笔者采用数字散斑相关技术(DSCM),提取三聚氰胺改性脲醛树脂胶黏剂(MUF)、酚醛树脂胶黏剂(PF)、脲醛树脂胶黏剂(UF)与荻草形成的3种胶合界面在拉伸剪切过程中的位移场信息,分析不同变形阶段试件的应变分布,以揭示荻草胶合界面的破坏机制。结果表明:加载过程中荻草与胶黏剂的界面两端产生应变集中,应变沿拉伸方向向界面中心扩展,并在界面两端首先出现破坏现象;PF-荻草胶合界面应变集中现象最明显,而MUF-荻草胶合界面剪切应变分布均匀,具有最优的胶合强度。

Silvergrass is a natural biomass and has great potential as reinforced material in composites. To investigate the interface failure mechanism of silvergrass composites,the displacement field information of the interfaces of melamine-urea-formaldehyde resin（MUF）-silvergrass,phenol-formaldehyde resin（PF）-silvergrass and urea-formaldehyde resin（UF）-silvergrass in the process of tensile shearing were abstracted with digital speckle correlation method（DSCM）.Results indicated that strain concentration occurred in the two ends of interface and extended to interface center along the tensile direction. The interface fracture also occurred first in the two ends. The PF-silvergrass interface showed the most obvious strain concentration during the tensile process,while the MUF-silvergrass interface presented the highest bond strength with better strain distribution.