纸蜂窝夹层结构模态振型构建及振能传递率预测研究

It is difficult to characterize and simulate the multiple reflection impact and vibration during evaluating the vibration damping of paper honeycomb sandwich structure. The difficulties are that the vibration transmitting is multi modal and the mechanism of the energy absorption and dissipation is complex. The project will research on the vibration transmitting characteristics of paper honeycomb sandwich structure, summarize the effect factors and the vibration transmitting regulation and reveal the vibration damping mechanism. Considering the structure geometric parameter and the raw paper elastic modulus, the project will research on the relationship between the dynamic cushioning properties and honeycomb structure and vibration frequency. Acorrding to this, the paper honeycomb material and packaged product will be constructed to a system. Cosidering the damping ratio of paper honeycomb sandwich panel, the model of energy absorption and dissipation of paper honeycomb sandwich structure will be constructed and modified by ANSYS and modal analysis method. The vibration transmitting equation will be solved by modal strain energy method. It can provide the science and theory evidence of the optimizing design and material selection of cushion material for the aeronautical equipment, furniture and package.The project aims to fill the blank of the quantified evaluation for the vibration damping and construct a pair of theory and method of cushioning property characteristics for paper honeycomb sandwich structure.

纸蜂窝夹层结构减振性能评估时遇到多次反复冲击和振动无法表征和模拟的难题，其难点是纸蜂窝结构振动传递具有多模态性且其振动能量吸收和耗散机制复杂。本项目拟研究纸蜂窝夹层结构振动吸能影响因素和规律，揭示其减振机理；考虑材料结构几何参数和原纸弹性模量，研究纸蜂窝结构振动缓冲特性与纸蜂窝结构和振动频率的关系；在此基础上，将纸蜂窝材料对被包装物的缓冲构造成一个系统，考虑纸蜂窝夹层板的阻尼比，采用有限元法和设计参数型模型修正方法，从理论上构建和修正纸蜂窝夹层结构振动能量吸收和耗散模型；采用模态分析法，探究纸蜂窝结构的各阶模态频率、阻尼比和模态振型，进一步求解纸蜂窝夹层结构振动传递率评估方程；为纸蜂窝夹层结构在航空、家具、包装等缓冲应用中的结构优化设计和材质选择提供科学的判据。本项目旨在填补纸蜂窝夹层结构减振性能定量评估的空白，建立一套蜂窝夹层结构缓冲性能表征分析理论与方法。

该项目执行期是2017.1-2020.12，是我们团队2012年完成的国家自然科学基金青年基金项目的延续，主要研究内容是纸蜂窝夹层板振动传递特性的有限元仿真、纸蜂窝夹层结构最大振动传递率普适性评估方程、蜂窝结构因素对纸蜂窝夹层板-质量系统的主共振频率的影响、蜂窝结构参数（胞元边长、纸板厚度）和载荷质量对系统阻尼耗能的影响规律、纸蜂窝夹层板振动耗能评估方法等。主要结果如下：利用有限元仿真方法可以模拟纸蜂窝夹层板-质量系统的共振频率和振动传递率，共振频率的仿真值与实验结果误差小于4%；标准温湿度（23℃、RH50%）条件下的5种纸蜂窝夹层结构的最大振动传递率实验值，得到最大振动传递率拟合方程为；相对湿度对纸蜂窝夹层板缓冲包装系统主共振频率的影响类似抛物线形状，相对湿度增大主共振频率降低；主共振频率同时也随静应力、胞元边长及夹层板厚度的增大不断降低。包装系统的阻尼耗能取决于包装材料的振动传递特性，若获得材料的振动传递率-频率曲线，便可计算系统的阻尼耗能；蜂窝结构参数和载荷质量对蜂窝纸板-质量系统共振时能量耗散的影响规律为：随着胞元边长或纸板厚度增大，蜂窝纸板共振处的阻尼耗能增大；载荷质量越大，系统在共振时的阻尼耗能越大。本项目的研究为包装系统的阻尼耗能计算和防振性能评估提供了基本方法，为缓冲包装优化设计提供了理论依据。