双曲正切函数型弹性体材料的缓冲包装设计

采用以弹性体材料的力学数据进行缓冲馐设计的方法，对双曲正切函数型弹性体材料的缓冲包装设计进行了详细的理论推导，得出了计算缓冲垫结构尺寸关系式。     

正切型弹性体材料的缓冲包装设计

提出一种利用正切型弹性体材料的力学数据进行缓冲包装结构设计的方法,对这种方法的原理进行详细的理论推导,得出计算缓冲垫结构尺寸的关系式。该关系式简单实用,设计出的缓冲衬垫具有最佳的理论缓冲效率。     

浅谈弹性体材料在包装上的应用

本文主要简要介绍了什么是弹性体材料,弹性体材料的分类,以及弹性体材料在医疗和食品包装行业、包装用热熔胶、热收缩膜和缓冲包装上的应用。弹性体材料的优良性能使其有着十分广阔的发展前景。     

常用缓冲包装材料静态压缩特性试验研究

通过试验研究，阐述了国产常用缓冲材料静态压缩特性，同时绘制了相应的静态压缩特性曲线图，并与美国MIL－HDBK－304中缓冲材料曲线图进行比较，为包装设计工作者进行缓冲包装设计选择相应的缓冲材料提供参考。     

两种缓冲材料并列组合的包装设计

提出了一种利用线弹性体材料的力学数据进行缓冲包装结构设计的方法,进行了详细的理论推导,得到了计算两种线弹性缓冲材料并列组合时结构尺寸的关系式。并对组合条件下的缓冲效果进行了讨论。     

EPE缓冲性能测试及缓冲包装设计方法

目的建立缓冲材料性能数据库,为缓冲包装设计提供数据支持,获得科学的缓冲包装设计方案。方法依据GB/T 8167—2008《包装用缓冲材料动态压缩试验方法》对EPE的缓冲性能进行测试,依据GB/T 8169—2008《包装用缓冲材料振动传递特性试验方法》对EPE振动传递特性进行测试。结果获取了EPE最大加速度-静应力曲线和振动传递率-频率特性曲线,建立了EPE缓冲包装设计流程,编制了EPE缓冲包装设计软件。结论通过实例验证了软件的可行性,提高了设计效率和质量,为EPE材料的缓冲包装设计提供了依据。     

缓冲衬垫CAD系统的研究

传统的缓冲包装设计，考虑流通环境，根据实验或经验得出的产品脆值，确定缓冲衬垫的种类及结构尺寸，然后进行校核。通常要反复实验与比较，才能筛选出合理的设计结果。其设计在很大程度上依赖于设计人员的自身经验、破坏性试验所得的数据，这就造成产品和缓冲材料的浪费，并且设计过程需时较长，在一定程度上制约了缓冲包装设计的发展。利用基于VC平台开发的缓冲衬垫CAD系统进行缓冲包装设计，能使设计人员从繁杂的手工设计中解放出来，显著地缩短了产品的研发周期，避免了对产品的破坏性试验。对于产品的包装，特别是对于精密电子产品的包装，其经济效益是相当可观的。开发缓冲衬垫CAD系统进行计算机辅助设计，是缓冲包装发展的必然趋势。     

包装用缓冲材料性能分析

缓冲包装材料的性能在很大程度上取决于所选用的缓冲材料的力学特性。因此，要设计出一个性能优良的缓冲包装系统的逻辑结构，需要在缓冲包装的系统结构分析中，充分了解缓冲材料的力学性能，根据待包装产品特性和流通环境的输入影响，合理选用缓冲包装材料。[编者按]     

C楞瓦楞纸板跌落缓冲包装优化设计

目的研究C楞瓦楞纸板的非线性包装系统在运输过程中的跌落特性,建立非线性包装产品系统模型,并得到系统动力学方程。方法依据物品响应加速度小于许用值及材料用量最小化等2个原则,进行缓冲包装优化设计并获得最优解。结果所建立的缓冲模型,可以直接用于缓冲包装设计。结论克服了用最大加速度-静应力曲线来设计缓冲包装需要大量实验和较多数据的弊端,为其他缓冲材料在缓冲包装设计中提供一般方法。     

台式电脑整体式缓冲包装结构设计

本文通过运用系统的缓冲包装结构设计方法论述了新型台式电脑整体式缓冲包装结构的设计过程，并通过优化，突出了整体式包装在节约材料的同时提高缓冲效率的特点。     

复合材料中纱束的几何形态

在预测三维机织复合材料力学性能时, 将纱线特别是纬纱横截面假设成何种形状一直众说纷纭。本文中假设纬纱截面形状分别为圆形、 跑道形、 凸透镜形、 矩形, 经纱横截面形状为矩形, 采用刚度平均法和等应变力学模型计算了4种角联锁结构复合材料的弹性模量, 经与复合材料的数字图像对比分析和实验验证表明, 圆形纬纱截面形状假设与数字图像相差较大, 与其它截面形状假设的弹性模量预测结果相差也较大, 跑道形、 凸透镜形、 矩形等纬纱截面形状假设彼此间弹性模量预测结果的差异很小, 与实验数据也具有较好的一致性。      

Phantom materials for elastography

Acoustic and mechanical properties are reported for gelatin materials used to construct tissue-like phantoms for elasticity imaging (elastography). A device and procedure for measuring elastic properties are described. The measured compression forces were comparable to results obtained from finite element analysis when linear elastic media are assumed. Also measured were the stress relaxation, temporal stability, and melting point of the materials. Aldehyde concentration was used to increase the stiffness of the gelatin by controlling the amount of collagen cross-linking. A broad range of tissue-like elastic properties was achieved with these materials, although gels continued to stiffen for several weeks. The precision for elastic modulus measurements ranged from less than 0.1% for 100 kPa samples to 8.9% for soft (<10 kPa), sticky samples     

Probing of Micromechanical Properties of Compliant Polymeric Materials

Scanning force microscopy (SFM) was used for probing nanomechanical properties of compliant polymeric materials with lateral resolution from 20 to 140 nm and indentation depths from 2 to 200 nm. Sneddon's, Hertzian, and Johnson–Kendall–Roberts theories of elastic contacts were tested for a variety of polymeric materials with Young's modulus ranging from 1 MPa to 5 GPa. Results of these calculations were compared with a Sneddon's slope analysis widely used for hard materials. It was demonstrated that the Sneddon's slope analysis was ambiguous for polymeric materials. On the other hand, all models of elastic contact allowed probing depth profile of elastic properties with nanometre scale resolutions. The models gave consistent values of elastic moduli for indentation depth up to 200 nm with lateral resolution better 100 nm for most polymeric materials.     

On approximate symmetries of the elastic properties and elliptic orthotropy

The theory of anisotropic elasticity was originally motivated by applications to crystals, where geometric symmetries hold with high precision. In contrast, symmetries of the effective elastic responses of heterogeneous materials are usually approximate due to various imperfections of microgeometry. A related issue is that available data on the elastic constants may be incomplete or imprecise; it may be appropriate to select the highest possible elastic symmetry that fits the data reasonably well. Some of these problems have been discussed in literature in the context of specific applications, primarily in geomechanics. The present work provides a systematic discussion of the related issues, illustrated by examples on the effective elastic properties of heterogeneous materials. We also discuss a special type of orthotropy typical for a variety of heterogeneous materials - elliptic orthotropy - when the fourth-rank tensor of elastic constants can be represented in terms of a certain symmetric second-rank tensor. This representation leads, in particular, to reduced number of independent elastic constants.     

The Analytical and Numerical Study on the Nanoindentation of Nonlinear Elastic Materials

In nanoindentation testing of materials, the analytical/numerical models to connect the indentation load, indentation depth and material properties are crucial for the extraction of mechanical properties. This paper studied the methods of extracting the mechanical properties of nonlinear elastic materials and built general relationships of the indentation load and depth of hyperelastic materials combined with the dimensional analysis and finite element method (FEM). Compared with the elastic contact models and other nonlinear elastic contact models, the proposed models can extract the mechanical properties of nonlinear elastic materials under large deformation simply and effectively.     

Eine elastisch‐plastische Übergangsbedingung für die Tropfenschlagerosion von Gesteinen und Betonen

An elastic‐plastic transition criterion for the erosion of rocks and concrete materials by impinging liquid drops Depending on loading regime and material type, mineralic materials behave either elastic or elastic‐plastic if eroded by impinging water drops. A simple transition number that combines fracture toughness and compressive strength (respectively Vickers hardness), can be used to distinguish between both modes. Conventionally ‘hard’ materials, namely granite and feldspars, own low transition numbers (high hardness values) and respond elastic. Conventionally ‘soft’ materials, namely limestone, cement mortar and schist, are characterised by high transition numbers (low hardness values) and show an elastic‐plastic response.     

聚丙烯/聚苯乙烯共混体系模量的细观力学研究

应用复合材料细观力学理论和相应分析模型,预测了聚丙烯/聚苯乙烯(PP/PS)共混体系的弹性模量并进行相应的试验研究。系统研究了非相容PP/PS共混物的体积含量和共混时间对共混物形态和弹性模量的影响,分析了细观形态与宏观力学性能间的关系。对PP/PS共混物的拉伸实验结果表明:微观力学模型在模量预报上是可行的,其中Mori-Tanaka法更有效,因为与半经验模型(如Halpin-Tsai法和改进的混合模型)相比,它没有试验参数,在材料设计时具有更大的优越性。     

孔隙形状及孔隙率对多孔材料弹性性能的影响

利用通用单胞法(GMC)计算了不同孔隙形状及孔隙率对多孔材料等效弹性参数的影响,计算中分别采用二维方形、圆形孔隙模型和三维立方体、球形孔隙模型模拟多孔材料。不同孔隙率下等效弹性参数的计算结果表明: 不同孔隙形状下,多孔材料等效弹性参数随孔隙率增大的退化程度不同;通过对比二维简化模型与三维模型的差异,发现二维简化模型对多孔材料等效弹性参数的估算值偏低。进一步将GMC计算结果和已有文献实验结果进行比较,发现两者具有较高的吻合度。最后将GMC模型与有限元、经验模型进行对比,得出GMC模型的局限性。综合计算结果,GMC具有一定的计算精度,可应用于工程实际分析中。     

A thickness mode acoustic wave sensor for measuring interface stiffness between two elastic materials

We studied thickness vibration of 2 elastic layers with an elastic interface mounted on a plate piezoelectric resonator. The effect of the interface elasticity on resonant frequencies was examined. The result obtained suggests an acoustic wave sensor for measuring the elastic property of an interface between 2 materials.