摘 要

材料的负泊松效应会产生刚度增强、缓冲吸能的优异特性。本文总结归纳到目前为止人们发现和提出的具有负泊松比的各种典型结构，最终选择一种经典负泊松比结构（内凹4阶旋转对称星形变体结构），将其与传统车用缓冲装置相结合，设计出新型缓冲装置截面结构，并与内凹六边形负泊松比结构缓冲块进行对比，分析结构参数对负泊松比缓冲块力学性能的影响。传统聚氨酯缓冲块的力学性能使得整车平顺性无法更进一步。为了提升整车的平顺性，对模型进行力学性能分析，设计出负泊松比新型结构，并对其进行建模和有限元仿真分析，与目前常见的、大多数运用的内凹六边形负泊松比结构进行对比，来分析是否更适合将其应用到汽车悬架缓冲块，所得结果对于提高车辆行驶的平顺性，进一步提高缓冲块抵抗冲击载荷的能力具有重要的指导意义。

本论文以提高汽车噪声、振动与声振粗糙度（NVH）性能为目标，主要工作包括以下几个方面：

（1）选择内凹4阶旋转对称星形变体结构为研究结构，基于MATLAB与Abaqus环境，以传统、典型负泊松比结构等为基础，进行典型、相应仿生负泊松比结构缓冲块设计建模，并以内凹六边形负泊松比结构为对比结构，对两种模型进行结构设计以及单胞模型的建模。

（2）针对内凹4阶旋转对称星形变体结构模型使用Abaqus进行建模以及有限元实验分析，包括单胞和2×2模型。针对对比单胞和2×2的内凹六边形负泊松比结构模型进行建模以及有限元实验分析。进行负泊松比缓冲块单轴压缩的数值计算，运用Abaqus显式求解器进行显式求解，研究负泊松比缓冲块在单轴压缩过程中的载荷-位移特性、图像和变形过程，并分析缓冲块的应力和应变分布。

（3）两种负泊松比结构悬架缓冲块的对比。将实验结果进行总结对比，包括载荷一定单胞与多胞的对比，同一个模型不同载荷下的对比，两种结构模型的对比。得到结论。研究结果表明：内凹六边形结构相比较于内凹4阶旋转对称星形变体结构有着更好的力学性能，包括能够反映结构弹性的应力、缓震能力的应变、位移，所以可以得出内凹六边形负泊松比结构相比较于内凹4阶旋转对称星形变体结构更适合运用到汽车悬架缓冲块。

本文的特色是：选择了一种基于内凹4阶旋转对称星形变体结构，通过有限元分析软件进行仿真建模，实验与分析。再与常见的内凹六边形负泊松比结构进行对比，两者在不同载荷下，应力、应变、位移的对比，以及在相同以及不同载荷下，两种结构模型的对比、单胞与多胞的对比，进过多种对比。以此来获得最终结论。

关键词：负泊松比结构；有限元分析；参数化建模；悬架缓冲块；

Abstract

The Auxetic effect of materials will produce the excellent characteristics of stiffness enhancement and energy absorption. In this paper, various typical structures with negative Poisson's ratio, which have been found and put forward so far, are summarized, and a classical Auxetic structure (Re-entrant 4-order Rotational symmetry stars) is finally selected. The new cross-section structure of the buffer device is designed by combining it with the traditional vehicle buffer device, and compared with the Re-entrant Evans buffer block, the influence of structural parameters on the mechanical properties of the negative Poisson ratio buffer block is analyzed. The traditional polyurethane buffer block structure limits the ride comfort of the vehicle further. In order to improve the ride comfort of the whole vehicle, a new Auxetic structure with negative Poisson's ratio is designed. The model is modeled and analyzed by finite element method. The mechanical properties of the model are analyzed. Compared with the Re-entrant Evans structure with negative Poisson's ratio, it can be applied to the buffer block of the vehicle suspension to obtain a better load displacement characteristic curve.

In order to improve the performance of vehicle noise, vibration and Harshness (NVH), this paper selects a classical Auxetic ratio structure (Re-entrant 4-order Rotational symmetry stars) and applies it to suspension buffer block, analyzes the structural parameters and mechanical properties, compares the polyurethane buffer block, and obtains the conclusion. Compared with the two structures, the results are of great significance to improve the ride comfort of the vehicle and the ability of the buffer block to resist the impact load.

The main work of this paper includes the following aspects:

(1) Based on MATLAB and ABAQUS environment, the typical and corresponding bionic negative Poisson's ratio buffer block is designed and modeled based on the traditional and typical negative Poisson's ratio structure, and the Re-entrant Evans structure ratio structure is the comparative structure. The two models are designed and the single cell model is modeled.

(2) ABAQUS was used to model and analyze the Re-entrant 4-order Rotational symmetry stars variant structure model, including cell and 2 × 2 model. In this paper, Re-entrant Evans structure ratio structure with single cell and 2 × 2 is modeled and analyzed by finite element experiment. The numerical calculation of the negative Poisson's ratio buffer block in uniaxial compression is carried out. The ABAQUS explicit solver is used to solve the problem. The load displacement characteristics, image and deformation process of the negative Poisson's ratio buffer block in uniaxial compression are studied, and the stress and strain distribution of the buffer block are analyzed.

(3) Comparison of two suspension buffers with negative Poisson ratio. The experimental results are summarized and compared, including the comparison of single cell and multicellular, and the comparison of two structures. Get the conclusion.

The results show that the Re-entrant Evans structure ratio structure has better mechanical properties than the Re-entrant 4-order Rotational symmetry stars variant structure, including the stress, strain and displacement that can reflect the elasticity and cushioning ability of the structure, so it can be concluded that the Re-entrant Evans structure ratio structure is more suitable for automobile suspension cushioning than the Re-entrant 4-order Rotational symmetry stars variant structure Punch block.

The characteristics of this paper：the Re-entrant 4-order Rotational symmetry stars variant structure is selected, and the finite element simulation modeling, compression experiment and analysis calculation are carried out through the finite element analysis software ABAQUS. Compared with the common Re-entrant Evans structure ratio structure, the stress, strain and displacement of the two structures are compared under different loads, as well as under the same and different loads, the comparison of the two structural models, the comparison of single cell and multi cell, has been compared in many ways. In order to obtain the simulation results.

Key Words：Auxetic structure；finite element analysis；parametric modelling；Suspension jounce bumper；