高分子复合减振钢板的研究及其应用进展

由钢板和高分子材料复合制得的减振钢板是近年来国内外迅速发展的新型材料，具有显著的减振、降噪的作用，是振动、噪声场合替代纯金属板材的理想环保产品。论述了减振钢板的制造方法、减振性能和成形性能，简述了减振钢板在国内外的应用进展和应用实例．并提出了今后研究减振钢板应重视的问题。     

柴油机复合降噪钢板解决方案

多年前,某款9L柴油机使用的钢板式齿轮室盖为了满足发动机减振降噪要求,采用进口零件。近年来,国内某钢板供应商致力于复合降噪钢板的研究,现已经成功研发出具有减振降噪功能的复合降噪钢板。     

微小卫星帆板展开火工冲击减振结构研究

以某卫星太阳帆板展开时卫星本体所受的冲击为研究对象,设计了一种蜂窝夹层板式冲击减振装置。从减振设计的角度出发,对冲击响应动力学模型、冲击减振设计要点进行了详细的说明。通过引入弹簧单元等对蜂窝夹层板及附属结构进行改进,并对该系统法向进行冲击特性试验研究,分析了该冲击减振装置应用于卫星后的动力学响应。结果表明,蜂窝夹层板减振装置具有良好抗冲击性能,应用于卫星单机安装板,能够有效减少冲击响应,同时满足发射条件,该设计合理。     

国内彩涂线现状及前景

1市场前景 彩色涂层钢板是将成卷的金属薄板涂上涂料或层压上塑料薄膜后,以成卷或单张出售的有机材料/金属复合板材.所以又称作有机涂层钢板、预涂卷材、预涂滚钢板、塑料复合钢板等.在我国彩色涂层钢板叫法较流行,并简称为″彩涂板″或″彩板″.     

钢板－高聚物－钢板层压复合材料的成形性研究

采用Ｖ形弯曲试验对钢板－高聚物－钢板层压复合材料的成形性进行了研究。结果指出，高聚物结构对成形性影响很大，增加钢板表面粗糙度和适当加大粘合压力，可改善层压复合材料的成形性。Ｖ形弯曲过程中，上下钢板间发生错动位移，其位移量与弯曲半径、高聚物层厚度等因素有关。     

阻尼结构减振性能的测试及分析

车身壁板的振动和噪声影响车辆NVH性能,在车身壁板粘贴阻尼衬层能够起到减振降噪的作用。利用强迫共振法测试基板(钢板)、自由阻尼结构(钢板+纯橡胶)、约束阻尼结构(钢板+纯橡胶+约束层)以及多层阻尼结构(钢板+纯橡胶+约束层+纯橡胶)四种阻尼结构试样。分析试样频谱图共振曲线得到如下结论:钢板附上衬层后的共振频率均要比原钢板试样的共振频率小;自由阻尼结构、约束阻尼结构、多层阻尼结构相对于基板的减振百分比分别为64.19%、71.77%、73.66%,减振效果依次增强;钢板、自由阻尼结构、约束阻尼结构、多层阻尼结构的阻尼因子分别为0.008、0.019、0.030、0.032,阻尼因子越大,阻尼性能越好,减振性能越强。并且从微观力学角度,对自由阻尼结构、约束阻尼结构、多层阻尼结构的减振机理进行了分析。     

多机通信在复合钢板生产过程中的应用研究

为提高减振复合钢板的生产质量、精度。采用PC机与单片机主从式多机通信方法。设计了以单片机分别对复合钢板生产过程中所需树脂材料温度、钢板卷曲速度及钢板厚度信息进行采集并传送至PC机。通过PC机进行信息处理并向单片机发送控制命令的系统。从而使复合钢板生产的过程中树脂材料温度控制在所需范围,复合钢板厚度达到精度要求。通过理论分析。验证了该方法的有效性。     

空间桁架复合结构的阻尼减振分析与试验研究

为了解决桁架复合结构振动响应过大,光电学仪器可能发生失效的问题,利用在桁架管壁和箱体面板上敷加粘弹性约束阻尼层的方法对整体结构进行减振。采用有限元分析软件Nastran对原结构和敷加粘弹性约束阻尼层的桁架复合结构进行给定工况下的振动特性分析,得到了桁架复合结构指定位置的振动加速度响应曲线。以阻尼因子大小作为减振效果评价指标,通过对粘弹性约束阻尼层的厚度进行优化和对比分析,最终得到了最优的粘弹性约束阻尼层设计参数。试验结果表明,粘弹性约束阻尼层对于空间桁架复合结构具有良好的减振效果,试验数据和仿真结果一致,减振方案切实可行。     

减振复合钢板生产中树脂恒温控制方法研究

分析了减振复合钢板生产中树脂加热过程,建立被控对象在小偏差情况下的数学模型,并研究采用模糊-PID联合控制器实现树脂材料的恒定温度控制方案,在系统存在较大偏差时采用Fuzzy控制加快系统响应速度,当系统偏差较小时采用PID控制以获得较好的控制精度.最后对该方案仿真结果与纯PID和模糊控制方案进行对比分析,得出模糊PID联合控制器适于减振复合钢板树脂恒温控制.     

粘弹性材料夹芯钢夹层板疲劳实验研究

本文开展了以聚氨酯弹性体为夹芯,面板为钢板的夹层板的三点弯曲疲劳实验,研究了粘弹性夹芯对夹层板疲劳性能的影响。首先开展了钢板材料(65Mn)的纯弯曲疲劳实验,获得钢板材料的弯曲S-N曲线,然后对聚氨酯弹性体夹层钢板开展了疲劳实验,研究了加载频率对夹层板载荷响应的影响,实验结果表明,夹层钢板在疲劳实验的过程中体现出明显的粘弹性特征,夹芯板结构的荷载响应与加载频率密切相关。同时,在面层钢板不发生屈服的情况下,在较大加载次数内不会产生疲劳破坏,说明聚氨酯弹性体存在具有良好的阻止裂纹扩展的功能,对面板的约束作用极大地提高了面板的疲劳极限。     

CO2 laser butt-welding of steel sandwich sheet composites

Steel sandwich sheets compared with conventional steel exhibit significant performance improvements such as lower density, higher specific flexural stiffness, and better sound and vibration damping characteristics. However, the main challenge for the broad industrial use is that the joining and assembling methods be used in such a way so as not to alter significantly these characteristics. In the present paper, a laser welding of steel sandwich is examined. The feasibility study of the laser butt-welding of sandwich steel sheets with a CO₂ laser beam has revealed that such an approach is possible. A theoretical model of the laser welding process is developed for the investigation of the laser beam impact on both the core and the outer steel layers of the sandwich material. The model presented is based on a novel idea for the simulation of the heat source through the finite element analysis for the estimation of the temperature distribution. Additionally, the effect on the quality of the weld, the strength of the welded sheet, and its damping characteristics are also experimentally investigated and prove that laser welding can be considered as an alternative joining process.     

Development of application technique of aluminum sandwich sheets for automotive hood

Objective of this study was to develop basic techniques in order to apply aluminum sandwich sheets for an automotive hood part. The aluminum sandwich sheet is the material fabricated by adhering two aluminum skins to one polypropylene core. When it has the same bending stiffness as a steel sheet, it is 65% lighter than the steel sheet and 30% lighter than an aluminum alloy sheet. Therefore, it is notified exclusively as good substitutive materials for a steel body to improve the fuel efficiency. Through aluminum sandwich sheet, however, it has relatively lower formability than that of the steel sheet for automotive application. In this study, we developed application techniques of the aluminum sandwich sheet for automotive hood. The various formability evaluations were carried out in order to secure the fundamental data for the measurement of sheet metal forming and the establishment of optimum application conditions of the sandwich sheet. From these results, it was found that the sandwich sheet could reduce the weight and maintain the flexural rigidity simultaneously comparing to the steel sheet.     

Analysis and modeling of flexural deformation of laminated steel

Steel/polymer/steel laminate sheets, commonly known as laminated steels, received attention for their superior noise damping properties in automotive applications. Published work indicates that the tensile properties of the laminated steel follow the prediction of the rule of mixtures. The flexural response of the laminated steel, however, depends on the type of the sandwich configuration. The flexural rigidity of the vibration-damping type of laminated steel is lower than the value calculated using beam theory. In industrial scale numerical simulations, automotive body panels are usually represented by using a single layer of shell element. Limited research work on finite element (FE) modeling of laminated steel has indicated that the vibration-damping type of laminated steel is better represented by using two layers of shells. It is logical to relate the simplest FE representation to the way the flexural rigidity of the laminated steel that conforms to the prediction using the beam theory. This paper examines the flexural response of the vibration-damping type of laminated steel through the comparison of beam theory predictions with the experimental results for cantilever beam and three-point bending configurations. It was found that the analytical solution for the split beam is in good agreement with the experimental results. This finding confirms the FE model that represents the vibration-damping type of laminated steel using two layers of shell with tied interface. The simulations using this method yielded good correlations with the experimental results for the two flexural loading cases studied in this paper.     

夹层钢板冲压成形数值仿真的计算模型分析

介绍夹层钢板的结构及其冲压成形性能，总结了夹层钢板冲压成形数值仿真的计算建模理论，包括等效单层理论和等效多层理论。对这两种建模理论进行比较，指出了这两种理论模型的适用情况，等效多层理论建模更符合实际夹层钢板结构情况，其数值仿真结果精确度较高，等效多层理论模型应为冲压成形仿真计算模型的重点发展方向。指出了等效多层理论所面临的问题。     

考虑连接性的三明治阻尼复合结构拓扑优化设计

三明治阻尼复合结构的力学性能取决于阻尼层材料的性能,综合考虑该结构的阻尼性能和可制造性要求,提出了一种面向结构宏观性能并考虑连接性的三明治阻尼复合结构拓扑优化设计方法。以最大化结构模态阻尼比为目标,考虑微结构刚度相材料的连接性,通过组合强制性连接约束法和非线性扩散法,构建了连接性约束下的阻尼复合材料微结构的优化设计模型,并结合3D打印技术实现了三明治阻尼复合结构的制造。运用所提方法对典型结构进行优化设计,得到了刚度相保持连接的阻尼复合结构,且优化后的结构阻尼变大,结构的频率响应变小,实现了三明治阻尼复合结构材料结构设计制造协同优化设计。仿真和实验结果表明,在微结构上存在最优的阻尼材料体积分数使优化后的三明治结构频率响应最小。     

粘结叠片工件外圆加工参数选取的可视化算法

针对粘结叠片工件的结构特点,分析了粘结叠片工件的外圆加工特性,对粘结叠片工件加工过程中的切削用量参数进行理论分析,建立以生产效率为目标的函数模型,应用可视化算法在各种约束条件下寻找其最优的加工参数,使粘结叠片工件能够在加工过程中实现快速而准确地定量各切削用量参数,从而缩短加工时间。以硅钢片黏结叠片工件为例,应用可视化算法,成功加工出了符合要求的圆柱体粘结叠片工件。     

Analysis of sandwich sheet rolling by stream function method

A mathematical model for symmetrical sandwich sheet rolling is proposed by using the stream function method and the upper bound theorem to investigate the plastic deformation behavior of sheets at the roll-gap. The velocity fields derived from the newly proposed stream functions can automatically satisfy the volume constancy and the velocity boundary conditions within the roll-gap. Effects of various rolling conditions such as the thickness ratio and flow stress ratio of sheets, total thickness reduction, friction factor between the sheet and roll, etc., upon the thickness ratio of the rolled product, the relative length of the plastic region in each layer, rolling force and rolling power are discussed systematically. Furthermore, experiments on sandwich sheet rolling are also conducted by employing aluminium, mild steel and stainless steel as layers of sandwich sheets. It is found that the theoretical predictions of the thickness ratio of the rolled products and rolling force are in good agreement with the experimental measurements. Through the study, it becomes clear that the proposed analytical method is applicable for simulating the sandwich sheet rolling processes and is able to offer useful knowledge in manufacturing sandwich sheets.     

Crushing of soft-core sandwich profiles: experiments and analysis

The present paper investigates the mechanics of the crushing of sandwich profiles through component testing and theoretical analysis. Experiments were run showing that the underlying folding mechanism of sandwich profiles is very different from that of solid-section thin-walled structures. In particular, the shear behavior of the core material was found to strongly influence the mechanics of energy absorption. The analysis focuses on the crushing behavior of double-cell profiles that are made of soft-core hybrid stainless steel assembly (HSSA) sheets. Both material and structural tests were performed. It is demonstrated that the shear strength of the HSSA fiber core is small as compared to the face sheet properties. When subjected to bending, the core deformed in the shear mode, whereas the facings bent independently. Based on this mechanism, a new shear-folding model for sandwich profiles is derived, incorporating the “shear crushing” of the sandwich core material. Theoretical predictions of the mean crushing force based on the present model compared very well with the experimental data.     

Damping in partially delaminated composites

A simple model was developed to predict the material damping in partially delaminated composites. First, we evaluated the damping loss factors experimentally in three kinds of specimens corresponding to various partial delamination areas. Second, the stiffness loss with delamination growth was assumed to result directly in the loss of energy from the oscillatory system because the delamination due to interlaminar stress is accompanied with stiffness loss in numerous laminated composites. By correlating the laminate stiffness reduction and the corresponding delamination area, a model for their basic material damping properties was formulated using the elastic-viscoelastic principle, the rule-of-mixtures law and modified Hashin’s Model. We predicted the damping of any partially delaminated composites with different stacking sequences based on Adams and Ni’s work and their basic damping loss factors. Numerical and experimental results demonstrate that damping is significantly influenced by the size of delamination area in laminated composites. In addition, experimental improvements in making accurate damping measurements are discussed as well.