竹质填充材料仿生结构设计及多尺度调控机制研究

Bamboo as a natural, environment-friendly and renewable material has huge potential to develop green and low-carbon products. The bottleneck problem of bamboo process and high valve application is the complexity of bamboo micro/macrostructures and the remodeling of its structures, which is a research hotspot in the field of biomass study. The research project will design the bionic elastic structural elements and network structures for bamboo filling material with bamboo slices and softened bamboo filaments as raw materials. And then the mechanical behavior pattern and energy absorption of the two kinds of bionic filling materials will be studied by studying their constitutive relations, finite element modeling, observing the microstructures and surface morphology. The effect of the microstructures of bamboo fibers, the mechanical properties of bamboo slices and softened filaments and the bionic structures of the two kinds of bamboo filling materials on their mechanical behavior patterns and energy absorption will be explored. And the mechanical regulatory mechanism of the two bionic filling materials of bamboo will be revealed from multi-scale point of view. Besides, the mechanisms of regulating environmental factors and adapting human will be studied by testing the human-bed pressure distribution, analyzing human-bed indentation shape, monitoring the temperature and humidity of human-bed surfaces, testing air permeability of the two bamboo filling materials. The studies will provide scientific theory basis for developing bamboo filling material with high performance, and new ideas for expanding the application field of bamboo and bionic structure designs.

竹材天然、环保、可再生，在绿色低碳产品发展中具有巨大的潜力。但其微/宏观结构的复杂性和组织结构重塑的困难性是影响竹材加工和高值化利用的瓶颈，也是生物质材料领域研究的热点和难点。本项目以竹片和软化竹丝为原材料，仿生结构设计竹弹片弹性结构单元体和网络多孔型竹质填充材料。在此基础上，通过本构关系分析和有限元模拟，结合竹材微观形貌和结构观察，研究两种竹质仿生填充材料的力学行为模式和能量吸收机制，探讨竹纤维微观结构、竹丝和竹片力学性能、两种竹质仿生填充材料结构与其力学行为模式、能量吸收性能等之间的关系，多尺度地揭示两种竹质仿生填充材料力学性能调控机制。另外，通过压力分布测试、压陷形状的有限元分析、温湿度监测、透气性测试，研究两种竹质仿生填充材料的环境因子调控机制和人体适用机制。本项目研究能够为开发高性能竹质填充材料提供科学理论依据，为竹质材料应用领域的拓展和仿生结构设计提供新思路。

探寻不可再生资源资源的替代品，开发性能良好的植物纤维填充材料是节能、减排和发展绿色、低碳经济的必然趋势。本项目充分利用竹材高弹、高韧的特性，在对竹材密度和模量分级的基础上，采用表面碳化、5%氢氧化钠+3%冰醋酸、1％的硬脂酸乙醇、5%氢氧化钠+0.5%高锰酸钾、1%硅烷偶联剂+80%乙醇以及冷冻干燥、微波处理等方法对竹丝和竹片进行改性，调控其力学性能和空隙结构。通过仿生丝瓜络梁架式网状结构结构和有限元仿真，开发制备了竹弹片弹性结构单元体；通过仿生丝瓜络多层级空隙结构，利用3D编织技术和低熔点低温热压成型技术，开发制备了3D竹质填充材料。在此基础上，深入探讨了竹弹片厚度、层数、间距、跨距、弹性模型、密度等竹弹片弹性结构单元体力学性能之间的关系，深入探讨了竹材纤维微/纳观结构、结晶度、实质物质含量、木质素含量等与竹弹片弹性结构单元体的力学性能之间的关系，深入探讨了竹丝编织形式、空隙结构、厚度、密度等与3D编织竹质填充材料力学性能之间的关系，揭示了两种竹质填充材料的力学行为模式和能量吸收机制。从而为两种竹质填充材料力学性能的调控提供了科学理论依据。另外，本项目利用丝瓜籽油制备微胶囊，并利用β-环糊精微胶囊、壳聚糖微胶囊等对竹弹片进行了改性，在此基础上，深入探讨了碳化处理、软化处理、微胶囊处理、冷冻干燥、微波处理等对竹质填充材料的透气性、吸湿性、散湿性抗霉性的影响，揭示了其影响机制。最后本项目利用所开发的竹弹片弹性结构单元体制备了竹质弹簧床垫，并通过与乳胶床垫、棕榈床垫进行分析，从支撑性能、缓压性、人-床界面温湿度、人睡眠行为、睡姿、睡眠质量、肌肉放松程度、生理参数等角度，深入探讨了竹弹簧床垫对人体的适用性，揭示了其适人机制。在此基础上，本项目提出了竹质床垫支撑性能定量化评价的方法，并开发了检测装备，制备了行业团体标准和国家标准，目前在行业内得到了广泛应用。