缓冲包装系统跌落破损边界曲线研究

建立了线性和非线性缓冲包装系统的无量纲跌落冲击方程,得到了产品最大加速度响应,提出了评价线性和非线性包装系统产品安全与否的跌落破损边界曲线概念。对于线性包装系统,固有频率和跌落冲击速度是产品跌落破损的评价量;对于非线性包装系统,系统参数和无量纲跌落冲击速度是产品跌落破损的评价量。     

缓冲包装设计中的简化问题之一:系统自由度的简化

对缓冲包装设计中如何简化系统动力学模型的自由度数的问题进行了探讨。重点研究了双自由度缓冲包装系统受冲击力作用时的简化问题。提出了相应的简化方法和简化条件。     

缓冲包装的跌落仿真

利用有限元软件ANSYS/LS-DYNA的跌落模块(Drop Test Module),建立电脑液晶显示器缓冲包装系统的有限元模型,模拟缓冲包装系统的跌落响应试验,得到了液晶显示器的应力应变云图,和加速度响应等动态特性,获取了相关数据,进而利用数据反复修改模型参数,优化电脑液晶显示器的缓冲包装结构及尺寸,设计出合理的电脑液晶显示器缓冲包装。     

阻尼对非线性缓冲包装系统跌落冲击的影响

基于文（１）的结果，进一步研究了阻尼对非线性缓冲包装系统跌落冲击的影响，阻尼使非经性包装系统位移峰值和加速度峰值明显降低，但对脉冲持续时间几乎无影响。     

多自由度缓冲包装系统的平均能量设计法

利用系统的能量方程，通过控制系统的平均能量来控制系统的振动强度。     

缓冲包装的跌落冲击及其参数方程

对缓冲包装系统的跌落冲击过程的动态特性分三阶段进行了分析，以脆值理论作为基础，建立受跌落冲击的缓冲包装系统“无回跳”的参数方程。     

发泡聚乙烯缓冲包装结构设计

目的探讨由应力-应变曲线推导最大加速度-静应力曲线,进行发泡聚乙烯缓冲包装结构设计的方法。方法利用发泡聚乙烯的应力-应变曲线推导得到最大加速度-静应力关系,结合算例验证方法的可行性。结果得到了符合设计要求的缓冲材料的最小厚度值。结论此方法丰富了包装动力学的基本理论,方便了缓冲包装结构设计。     

聚乙烯泡沫缓冲系统跌落冲击过载仿真分析

目的将聚乙烯泡沫静态压缩特性引入有限元中创建材料,并应用于跌落冲击进行过载仿真分析。方法通过聚乙烯泡沫静态压缩实验,得到材料真实应力-应变曲线,并引入基于Ansys的Crushable Foam模型,最后仿真分析聚乙烯泡沫缓冲系统的跌落冲击过载,并与跌落实验结果进行对比分析。结果聚乙烯泡沫缓冲系统的仿真冲击加速度曲线与跌落实验曲线趋势基本吻合。结论基于Crushable Foam模型的聚乙烯泡沫静态压缩性能的引入可行、有效,并为非线性缓冲系统有限元分析提供了参考价值。     

发泡聚乙烯包装系统冲击谱研究

建立了发泡聚乙烯缓冲包装系统的缓冲模型,运用四阶变步长Runge-Kutta方法,计算出了此非线性系统在半正弦脉冲冲击下的冲击响应谱,并讨论了参数λ1,λ2和λ3对冲击谱的影响规律。     

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。     

Study of static cushioning properties and construction of a database for static cushioning properties

The rapid advance of computerization in industrial package design has led to a strong tendency toward CAD/CAM systems using personal computers for quick design and trial manufacturing. New tools based on a database of the cushioning properties of packaging materials will be needed for the design of package cushioning. Using a compression testing machine with computer control, an attempt has been made to construct such a database with registered characteristics for 47 samples of foamed polyethylene, foamed polypropylene and foamed polyethylene-polystyrene. This database offers the following functions and is recorded on floppy disk: (i) calculation of static cushioning properties (value); (ii) print-out of the computed results; (iii) drawing characteristic figures for designing package cushioning; (iv) indicating optimum value of static cushioning properties; (v) additional registration of new samples.     

Study of static cushioning properties: Automated data input and reliability test of static cushioning properties

A computer-controlled compression testing machine is used to compile a database of the static cushioning properties of package cushioning materials. Through research into automated data input procedures, so far not developed, a direct transfer program (ZABCON) has been devised, which allows direct access to the disk in which compression test data are stored. Elimination of manual data input has led to simplified and easy construction of a database, and the applied laboratory tests, such as that for determining the relationship between static cushioning properties and compression rate, can be performed quite readily. Also in this report, the application of the static cushioning characteristics of foamed polystyrene in the cushioning package design of dummy goods and the evaluation of its reliability by drop testing are discussed.     

Finite element analysis (FEA) applied to polyethylene foam cushions in package drop tests

Two designs of polyethylene (PE) foam cushions were compared, using a rigid ‘product’ of mass 5.6 kg, and an outer corrugated fibreboard box. The acceleration–time history for the product was measured when the box was dropped flat from 1 m onto a rigid floor. The data was processed to calculate the impact force as a function of the packaging deformation. Finite element analysis (FEA) predictions of the impact force vs. package deflection were accurate for end‐cap designs using Ethafoam, but underestimated the slope of the experimental force vs. deflection relation for corner‐cap designs. The corner‐cap design is more efficient in reducing the peak product acceleration for multiple impacts. The contribution of the corrugated board box to the impact response appears to be small. The FEA results were compared with those from the cushion curve design method and were found to better predict the performance of complex shaped cushions. Copyright © 2004 John Wiley & Sons, Ltd.     

Comparison of package cushioning materials to protect post‐harvest impact damage to apples

Damage to fruits and vegetables continues to be a big challenge as global markets become a reality. Worldwide distribution of sensitive produce is faced with various levels of impacts from shipping and handling. Despite a variety of packaging options available today, bruising damage is commonplace for post‐harvest apples throughout the supply chain. The major sources of bruising are compression, impact or vibration forces. Understanding where these forces occur can help reduce this type of mechanical damage to apples. The purpose of this study was to investigate the impact characteristics of foam net and corrugated board when applied as wrapping for individual apples. Two grades (count numbers 80 and 100) of “Fuji” cultivar apples imported to Thailand from China were studied. A simple ballistic pendulum test device was developed to measure bruise volume to impact energy relationship. A linear relationship for both types of apples was observed. Bruise volume occurrence probability and impact energy relationship fitted by linear regression were created for cushioned and bare apples. Absorbed energy of various cushioning materials was also calculated under compressive forces. Copyright © 2006 John Wiley & Sons, Ltd.     

梯形槽聚乙烯缓冲衬垫结构的有限元优化设计

目的探究梯形槽EPE缓冲衬垫结构的动态缓冲性能,优化缓冲衬垫结构,为后续缓冲结构设计提供科学的参考方案。方法以密度为23 kg/m3的EPE材料为试验对象,对材料样品进行静态压缩试验,数据处理得出应力-应变数据,将其导入Ansys Workbench材料库中,对产品衬垫系统进行有限元冲击模拟。将冲击理论计算结果与有限元分析结果进行对比。保持等效接触面积不变,对不同底角度数和开槽排布方式的产品衬垫系统进行有限元模拟,得出最大变形量、等效应力、速度等数据。结果底角小于70°时,缓冲结构整体刚度过小,导致跌落时产品触底,不能很好地保护产品;当底角大于70°时,度数为85°的缓冲衬垫等效应力最小,为0.0966 MPa,并且产品的速度改变量最小。底角为90°时,1个槽缓冲衬垫变形量最大,为30.282mm,等效应力为0.09681MPa。结论在结构设计时,可将底角85°、1个槽的缓冲结构作为设计的最佳参考值,以实现缓冲材料的减量化设计和最佳的保护性能的目标。     

集成化运输包装设计系统

介绍了集成化运输包装设计系统的需求,提出了系统模型,基于此模型分析和研究了各个模块的设计流程。设计的集成化运输包装系统可以完成产品的缓冲设计、纸箱设计和托盘设计,并对方案进行组合、优化和优选。设计了系统数据库,提出了系统总体设计流程。     

冲击压路机减振系统的参数化仿真研究

 为了减小冲击压路机作业时引起的冲击与振动,仿真研究了减振系统参数对作用于牵引车的冲击载荷的影响特性．通过分析冲击压路机的结构和作业特点,建立了减振系统的动力学方程．在UG软件中建立整机的实体模型,然后将其导入多体动力学仿真软件ADAMS中,建立包含轮胎与地面的动力学模型,在典型工况下仿真了整机的动力学特性,将仿真结果与试验数据对比,验证了模型的正确性．通过参数化设计研究方法将模型参数化,仿真分析了减振系统的刚度、阻尼参数变动时牵引载荷的变化,获得了参数影响的灵敏度曲线和载荷曲线,给出了参数值的合理范围．结果表明,系统的第1级阻尼和第2级刚度对牵引载荷的影响较大,整机仿真模型能够模拟冲击压路机的实际工况,为工程优化提供参考．     

A phenomenological constitutive modelling of polyethylene foam under multiple impact conditions

This paper extends the knowledge into the mechanical behaviour characterizations and constitutive modelling of polyethylene (PE) foam under multiple loading and unloading. The mechanical properties of PE foam subjected to single loading cases can be obtained by uniaxial compressive tests at quasi‐static and dynamic states. And the multiple loading and unloading behaviours of the foam can be revealed by consecutive drop tests. The major objective of this research is to propose a phenomenological model consists of shape function and modulus function, which can be predicted compressive response of PE foam for single loading cases. The constitutive models of foamed PE under multiple loading and unloading conditions are established by both using hyperbolic function, where the relations between coefficients and residual strain are introduced. And then, experiments are conducted to validate the proposed model by comparing the constitutive models proposed in this paper and those predicting by finite element software ABAQUS with those by experiments, showing that the proposed models are more accurate for predicting acceleration‐times curves of multiple drop scenarios.     

产品包装的人性化设计

产品和产品包装是不可分割的整体,在进行产品包装设计的时候,就要充分的考虑人的因素,不仅仅要考虑包装的基本功能,还要有很多和产品相关的人性化考虑.比如在包装给人的信息方面和使用方面,多站在使用者的角度来考虑.     

某型包装箱的低密度聚乙烯缓冲结构设计与分析

目的 基于低密度聚乙烯材料设计一种包装箱的缓冲结构,以满足冲击加速度的设计要求。方法 采用低密度聚乙烯材料对应的最大加速度-静应力曲线进行理论计算,设计出包装箱缓冲结构的初始模型,运用Ansys Workbench有限元仿真软件对包装箱整体进行水平跌落仿真,并对仿真结果进行分析。结果 当缓冲垫设计厚度为75 mm时,包装箱整体跌落后受到的最大冲击加速度低于40g,满足设计要求。结论 基于低密度聚乙烯材料设计的缓冲结构能够对包装箱提供有效的缓冲防护,缓冲性能满足要求。