一种新型高性能仿生负泊松比结构建模和优化方法研究

Possessing the unique properties of lower mass and higher energy absorption capability, Negative Poisson’s ratio (NPR) structure has broad application prospects in the modern automobile design and manufacture, however, the traditional NPR structure still needs to be improved with the low rigidity and poor durability. Based on the double arrow NPR structure, a new bionic high-performance NPR structure will be first proposed in this work to strengthen the properties of NPR structure and overcome its disadvantages at the same time after studying the constitution and mechanism of the skeletal muscle. Since the microstructure composition is complex and the microscopic parameters are mutually coupled, the modeling and parameters optimization methods of the bionic high-performance NPR structure are also fully studied in this work. Mechanical model of the new NPR structure is first built to study the mechanism and the finite element model based on a new Timoshenko beam model is then constructed to improve the analysis precision and efficiency. Considering the complex microstructure composition and coupled parameters, a new parameter optimization method of the bionic high-performance NPR structure which based on the adaptive parametric model is proposed to achieve the rapid performance optimization. At last, the new NPR structure is applied in the vehicle crash box to validate the research methods. By proposing a new bionic high-performance NPR structure and studying its modeling and optimization method, this work aims to construct the theoretic basis for the application of NPR structure in vehicle design and further improve the vehicle performance.

负泊松比结构在现代汽车设计中具有广泛应用前景，然而传统负泊松比结构在具有良好能量吸收能力和质量轻等优异性能的同时具有刚度低和耐久性差等不足。本项目将基于双箭头型负泊松比结构，研究和借鉴骨骼肌的结构和功能机理，提出一种新型高性能仿生负泊松比结构，既进一步增强负泊松比结构的优异性能又克服其不足，同时针对其复杂微观结构组成及微观参数相互耦合等问题，对仿生负泊松比结构建模和参数优化方法进行研究。通过建立仿生负泊松比结构的力学模型研究其内在机制，并基于新型Timoshenko大变形梁单元建立其分析模型从而提高分析的精度和效率,提出一种基于自适应参数化模型的负泊松比结构参数优化方法从而实现其性能的快速优化，并以汽车吸能盒为例进行应用和对其研究方法进行验证。本项目旨在通过提出一种高性能仿生负泊松比结构并研究其建模和优化方法，为负泊松比结构在汽车中应用提供理论基础，从而达到进一步提高汽车性能的目的。

项目针对仿生负泊松比结构的建模和优化方法展开研究，完成的主要研究内容有：.（1）研究了一种新型高性能仿生负泊松比结构，在进一步增强负泊松比结构优异力学性能的同时克服其容易应力集中和可靠性差等缺点；.（2）通过有效结合绝对节点坐标方程和几何非线性精确梁模型建立了一种新型Timoshenko梁单元，使其适合模拟负泊松比结构的复杂大变形，并采用欧拉角来提高梁单元的计算效率。.（3）提出了一种可用于负泊松比结构参数设计的E-HAM优化方法，在实际工程设计中可同时取得较好的效率和精度；设计了一种加强汽车正面碰撞保护的负泊松比结构防撞系统，并对该系统的设计参数开展了多目标鲁棒性优化；.（4）提出了将负泊松比结构用于汽车碰撞中的行人保护，通过合理设计参数使汽车与行人的碰撞中显著降低行人的几率和程度。.本项目完成后超额完成预定计划，以第一作者在国内外期刊上发表SCI论文5篇，国际会议论文2篇，申请发明专利11项，其中授权发明专利5项。本研究的开展推动了负泊松比结构的建模和优化方法研究，并为负泊松比结构在汽车碰撞设计中大规模应用提供理论基础，目前正与上汽通用五菱汽车有限公司和奇瑞汽车进行相关的推广应用洽谈。