The effect of pallet top deck stiffness on the compression strength of asymmetrically supported corrugated boxes

During unitized shipment, the components of unit loads are interacting with each other. During floor stacking of unit loads, the load on the top of the pallet causes the top deck of the pallet to bend, which creates an uneven top deck surface resulting in uneven or asymmetrical support of the corrugated boxes. This asymmetrical support could significantly affect the strength of the corrugated boxes, and it depends on the top deck stiffness of the pallet. This study is aimed at investigating how the variations of pallet top deck stiffness and the resulting asymmetric support affect corrugated box compression strength. The study used a scaled-down unit load compression test on quarter-scale pallet designs with different deckboard thicknesses using four different corrugated box designs. Pallet top deck stiffness was determined to have a significant effect on box compression strength. There was a 27%–37% increase in box compression strength for boxes supported by high-stiffness pallets in comparison with low-stiffness pallets. The fact that boxes were weaker on low-stiffness pallets could be explained by the uneven pressure distribution between the pallet deck and bottom layer of boxes. Pressure data showed that a higher percentage of total pressure was located under the box sidewalls that were supported on the outside stringers of low-stiffness pallets in comparison with high-stiffness pallets. This was disproportionately loading one side of the box. Utilizing the effects of pallet top deck stiffness on box compression performance, a unit load cost analysis is presented showing that a stiffer pallet can be used to carry boxes with less board material; hence, it can reduce the total unit load packaging cost.     

基于Ansys的双A型瓦楞纸板稳定性分析

目的基于Ansys研究大中型运输包装堆码过程中纸质外围框的双A型瓦楞纸板失稳问题。方法使用Ansys软件并结合APDL语言构建双A型瓦楞纸板有限元模型,然后对该模型进行特征值屈曲分析,得到使纸板发生屈曲的最小临界载荷和屈曲后纸板的变形情况,最后改变纸板的高度与长度,再进行多次特征值屈曲分析,分析纸板的高度和长度与纸板临界屈曲载荷的关系。结果纸板的临界屈曲载荷与纸板的长度成正比,与纸板高度的平方成反比。结论纸质外围框双A型瓦楞纸板更加适合包装高度较低的产品,以减少失稳的可能性,当双A瓦楞纸板所承受的力大于临界屈曲载荷时,可以在瓦楞纸板的外表面添加胶合板加强筋,承担一部分的承载压力,从而使瓦楞受力在临界屈曲载荷之下。     

民机部件 APU 门运输用瓦楞纸包装箱的优化设计

目的针对民机大型部件运输用传统木制包装箱结构重、成本高等问题,使用质量小、成本低的新型瓦楞纸材料研制民机大型部件运输用包装箱。方法以APU门为例,使用有限元软件MSC.Patran/Nastran计算APU门包装箱的强度,加载侧向载荷,使用木质材料和瓦楞纸板材料进行对比。结果同样的结构强度,瓦楞纸箱相比木制包装箱减重60%,瓦楞纸箱的侧向结构需要优化。结论瓦楞纸板用作民机大型部件的包装箱材料是可行的,且有很大的质量与成本优势,但设计中应全面考虑出现的各种载荷。     

出口商品瓦楞纸箱包装用料搭配的选择

出口商品纸箱包装用料搭配的选择，主要强调选用优良的箱纸板和瓦楞原纸，通过纸箱抗压强度和瓦楞纸板边压强度，原材料环压强度相互之间的关系揭示出，选用优质高强低克重的原材料是提高出口纸箱质量的一个有效途径。     

基于屈曲准则的瓦楞纸板强度仿真分析

分别建立了典型的A、C、B楞型单瓦楞纸板的有限元模型,计算了3种瓦楞纸板的临界屈曲载荷。以临界屈曲载荷为纸板抗压能力的判定准则,定量分析了3种瓦楞纸板的抗压能力,同时研究了材料与结构对瓦楞纸板抗压能力的影响及每种瓦楞纸板的材料抗压效率。分析结果表明,大瓦楞有更好的抗压能力,其抗压能力的提高主要是依靠其结构实现的,约束条件能够极大地改变瓦楞纸板的抗压效率。     

瓦楞纸箱板自动码垛机机械手设计初探

目的研究高效的、可集成于瓦楞纸箱生产线终端的瓦楞纸箱板自动码垛装置。方法通过对六自由度码垛机器人和机械式码垛装置进行研究,在分析其优缺点的基础上,结合企业的技术要求设计瓦楞纸箱板自动码垛装置。在设计方案中采用AHP法,结合企业的要求和生产现场的状况,选择机械式码垛设计方案。结果确定了新型瓦楞纸板箱码垛成套装置设计方案,论述了其工作原理并讨论了关键装置的设计要点,对抓取机械手的结构和运动轨迹进行了分析与优化。结论该设计方案采用2个机械手分别完成单层码垛和整层抓取操作,设计合理,满足企业的使用要求。     

Application of beam on elastic foundation to the interaction between a corrugated box and pallet deckboard

Corrugated boxes are ubiquitous in shipping and warehousing logistics. In physical distribution, corrugated boxes are often shipped in a unit load form where the interaction between the components determines the effectiveness and safety of the overall system. When lower stiffness pallets are used to support the corrugated boxes, the compression strength of boxes is reduced due to the uneven support conditions caused by the deforming top deckboards of the pallet. In this study, a modification of the principle of beam on elastic foundation was used to predict the effect of pallet deck stiffness on the performance of a corrugated box. In the model, the corrugated box acts as the elastic foundation, and the deckboard is represented as the beam. Pallet deck stiffness, pallet connection stiffness, and package stiffness are required model inputs. The resulting model was capable of predicting the normalized distribution of forces along the boxes' length sidewall but was not capable of predicting the compression strength of the box at failure.     

波纹钢腹板组合箱梁应力相关阻尼特性研究

基于应力相关材料阻尼理论,选择波纹钢腹板组合箱梁这一新型钢、混组合桥梁结构,通过波纹钢板和钢筋混凝土的单位体积损耗因子,由能量法推导求得波纹钢腹板组合箱梁的损耗因子公式。结合有限元计算的各个单元的应力得到损耗因子,根据一个振动周期能量耗散相等原理,求得等效阻尼比,并将其与实测结果进行比较。分析结果表明：波纹钢腹板组合箱梁桥材料阻尼值不是一个固定值,它是随着应力水平的提高而增大。在自由振动和车辆荷载激励状态下,波纹钢腹板组合箱梁的等效阻尼比建议取为0.3%。提出的损耗因子公式和等效阻尼比的计算可为波纹钢腹板组合箱梁桥动力分析中阻尼的取值提供参考。     

The Influence of Package Size and Flute Type of Corrugated Boxes on Load Bridging in Unit Loads

Shipping pallets often are designed with the assumption that the payload carried is flexible and uniformly distributed on the pallet surface. However, packages on the pallet can act as a series of discrete loads, and the physical interactions among the packages can add stiffness to the pallet/load combination. The term ‘load bridging’ has been used to describe this phenomenon. The study reported in this paper investigated the relationships of package size, corrugated flute type and pallet stiffness to load bridging and the resulting unit‐load deflection. The experimental results indicated that an increase in box size changed the unit‐load deflection by as much as 75%. Flute type was found to impact load bridging and the resulting unit‐load deflection. Changing the corrugated box flute type from B‐flute or BC‐flute to E‐flute reduces the unit‐load deflection by as much as 40%. Also, experimental data indicates that the effect of package size and corrugated board flute type on pallet deflection is the greatest for low stiffness pallets. The results provide information that can be used to design unit loads that use material more efficiently. Copyright © 2017 John Wiley & Sons, Ltd.     

Flexural stiffness of selected corrugated structures

Top‐to‐bottom compression strength of a corrugated fibreboard box is partly dependent on the load‐carrying ability of central panel areas of the box. The ability of these central panel areas to resist a bending force from loading may increase the stacking strength of the box. The difference in the compression strengths of boxes that have identical dimensions and were fabricated with identical components but different flute types, is primarily caused by flexural stiffness of the box panels. Top‐to‐bottom compression strength of boxes can be accurately predicted by flexural stiffness measurements and edge crush test (ECT) of the combined boards. This study was carried out to analyse the flexural stiffness, to measure bending force and bending deflection by a four‐point bending test for various corrugated fibreboards, and to provide the major constructional factors which play a role in improving the compression strength of the box. Copyright © 2004 John Wiley & Sons, Ltd.     

Effects of component properties and orientation on corrugated container endurance

Experiments are performed to determine the impact of several physical properties on the creep behavior of three different sets of corrugated containers subjected to static loading and a cyclic humidity environment ranging from 50% to 80% relative humidity in a 24 h period. One sample set had basis weights of the fluted medium varied from 68 to 205 g/m² while keeping the basis weight of the linerboard facings at 205 g/m². This varied the out‐of‐plane shear rigidity of the single wall board by a factor of three. Another set of corrugated samples investigated effects of lateral or linear corrugating by rotation of either linerboards, fluted medium or both. This equalizes hygroexpansivity and affects lifetime. A third series of boxes had barrier coatings applied to their surfaces to determine the effect on lifetime. Creep and lifetime are determined to be inversely related and a multiple regression model for lifetime was sought based on the data set. Homogenization of the corrugated board properties through either increased medium basis weight or component rotation (lateral or linear corrugating) and application of barrier coating will in general, increase the endurance of edge loaded corrugated board in cyclic humidity. Copyright © 2010 John Wiley & Sons, Ltd.     

瓦楞纸箱尺寸的优化设计

以产品为类直方体、外包装容器为瓦楞纸箱的托盘包装系统为研究对象,提出了能同时降低包装用料成本和仓储成本的瓦楞纸箱尺寸优化设计方法。介绍了优化设计方案,分别建立了瓦楞纸箱省料模型和托盘装载优化模型,从瓦楞纸箱设计、托盘装载、仓储空间各个环节进行优化,以提高托盘表面利用率和仓储空间利用率,降低包装成本,并给出了纸箱尺寸优化流程。     

太阳能组件的整体包装设计

目的对太阳能组件多片集装进行运输包装设计,为小型机电产品的整体包装设计提供一种方法。方法了解太阳能组件的产品属性、流通过程和环境条件,从产品的防护、装卸搬运、堆码、防潮、防静电等方面考虑,对托盘、内部缓冲装置、外包装箱等方面进行整体包装设计。结果内缓冲包装结构采用胶合板材质的木支架和木质固定块对组件进行支撑和固定,BC楞结合的五层瓦楞纸板做上下垫板,灰底白卡纸板作为纸护角对组件进行分割保护,利用PET打包带对组件和底部的瓦楞纸板垫板进行纵向2道捆扎,并对托盘的结构形式、材质、堆码、防护固定方式等进行设计,完成太阳能组件的整体包装过程。结论该整体设计方案能够完全满足太阳能组件的运输包装需求,在节省材料、降低成本的同时,提高了安全防护性,为小型机电产品的整体包装设计提供了思路。     

瓦楞纸箱运输包装系统设计

瓦楞纸箱是一种薄壁结构的绿色包装容器，广泛应用于商品包装。瓦楞纸箱运输包装系统的优化设计是一个多目标函数、多变量的优化问题，以仓储空间利用率最大为优化目标函数，瓦楞纸箱强度为约束条件，优化瓦楞纸箱结构、配料方案及装载模式，能够较全面进行纸箱优化设计，较好实现瓦楞纸箱对产品的安全保护、方便储运功能。     

Fatigue life prediction for GRP subjected to variable amplitude loading

A method of predicting lifetime to failure for any glass fibre reinforced composite system subjected to a complex load–time history has been developed. The prediction first requires the generation of a model to characterize the general fatigue response of the particular composite system. Once the models are derived they can be used to predict lifetimes to failure for any load–time history using a modified Miner’s damage summation rule and rainflow analysis. Variable amplitude fatigue testing of different GRP materials, using the same load–time history, allowed a comparison to be made between predicted and actual lifetimes to failure and was useful in verifying the accuracy and robustness of the life prediction methodology employed. The results from the life prediction models for three very different GRP systems showed themselves to be accurate predictors of fatigue behaviour for the variable amplitude loading condition investigated.     

电商包装方式对水蜜桃运输缓冲防震及货架品质的影响

目的 研究常规电商包装中不同缓冲材料和包装量对水蜜桃在跌落、随机振动条件下的损伤防护及货架品质的影响。方法 以“华玉”水蜜桃为试材，分别采用瓦楞纸隔板+单盒包装、聚乙烯发泡棉(EPE)内衬+单盒包装、瓦楞纸隔板+两盒包装及EPE内衬+两盒包装等4种形式包装后，依据ISTA 3A标准开展模拟公路运输实验，分析水蜜桃货架期品质变化。结果 瓦楞纸隔板+两盒包装在面跌落时的加速度仅为90.306 m/s²，缓冲性能比单盒包装更好，但其在随机振动中响应较大，而EPE内衬+单盒包装处理受随机振动影响最小，一阶共振响应和二阶共振响应分别为0.012 2 g²/Hz和0.014 3 g²/Hz。模拟运输后在常温货架条件下，瓦楞纸隔板+两盒包装的水蜜桃在货架期内始终保持较低的呼吸强度和乙烯释放量，维持较好的外观品质。相较于单盒包装，两盒包装对维持水蜜桃质地、可溶性固形物、总酸含量及外观品质具有积极作用。结论 综合来看，以瓦楞纸隔板为缓冲材料，两盒包装更有利于水蜜桃电商物流运输中的震动防护，并能较好地保持货架品质，为适宜水蜜桃的电商物流包装...     

瓦楞纸板和纸箱蠕变关系的研究

通过运用马基公式和瓦楞纸板和纸箱的蠕变模型,分析得到瓦楞纸板和纸箱蠕变可持续时间之间是一种线性关系,并用实验对这一结论进行了验证。为瓦楞纸板和纸箱蠕变时间关系建立提供了一种新的方式。     

瓦楞纸箱尺寸设计优化系统的开发

目的提高瓦楞纸箱尺寸设计过程的工作效率与准确性,缩短产品的开发周期。方法以瓦楞纸箱尺寸计算为主线,利用PHP语言和Mysql数据库设计一套从内装物排列方式优选一直到后期算出可堆码层数和堆码高度的瓦楞纸箱尺寸优化设计系统。结果通过实例演算可以看出该系统可以大大减小尺寸设计过程中的计算量与分析比较时间,大大提高工作效率。结论该系统具有一定的实用价值,但是还存在堆码强度安全系数需要经验确定,以及尚未涉及抗跌落及缓冲性能预测等问题,还有进一步提升的空间。     

大长宽比对纸箱抗压能力影响的研究与分析

对获取纸箱抗压能力的3种主要技术手段:试验测试方法、经典公式计算方法和计算机仿真模拟方法的优缺点进行了对比分析。选择0201型BC楞瓦楞纸箱为对象,分别采取试验测试和经典公式计算,在纸板材料、纸箱高度、周长相同的条件下,对长宽比从1～3范围变化的纸箱抗压能力进行了计算和测试。结果表明:长宽比从1变化到3时,纸箱的抗压强度先升再降;当长宽比为1.6左右时,抗压强度达到最大值。试验结果和利用经典抗压能力计算结果的对比分析表明,计算结果均较大地偏离了试验结果。由于不能充分考虑到纸板加工质量、纸箱成型工艺、温湿度及其它因素的影响,经典抗压能力计算公式均是偏保守的。     

平板玻璃运输包装设计及保护性能分析

目的采用瓦楞纸箱内衬聚氨酯泡沫衬垫设计平板玻璃运输包装,通过仿真分析检验设计的合理性与可行性。方法采用Creo parametric软件建立运输包装件模型,采用Ansys Workbench软件对模型进行仿真分析,完成静态堆码载荷仿真、模态仿真、随机振动仿真,并利用LS-DYNA与Ansys Workbench进行联合模拟跌落仿真。结果将瓦楞纸箱与木箱运输包装形式的仿真结果进行对比分析,得出相同静应力作用下,瓦楞纸箱包装的最大响应应力最小且分布均匀;随机振动过程中,虽然瓦楞纸箱相对于木箱形变量较大,但避免应力集中情况且满足变形限度要求;跌落过程中,瓦楞纸箱相对于木箱传递到平板玻璃的作用力较小,且避免了应力集中现象。结论综合分析结果,瓦楞纸箱加聚氨酯缓冲衬垫的运输包装形式设计合理,能够在运输过程中更好保护平板玻璃的安全,设计方案可行。