也谈瓦楞纸箱的结构设计

瓦楞纸箱的结构设计流派很多。澳大利亚瓦楞纸箱结构设计是把纸板用料面积、抗压强度和托盘利用率(即集装箱空间利用率)结合起来,比较科学,并在实践中收到了明显的效果。特别是他们发明了一整套的设计图表,能迅速选择纸盒、纸箱的最佳形状和尺寸,以及纸盒在纸箱中和纸箱在托盘上的最佳排列形式,能起到减少用料面积、降低纸板克重、节约运输成本等实际效果。     

也谈瓦楞纸箱的结构设计

瓦楞纸箱的结构设计流派很多。澳大利亚瓦楞纸箱结构设计是把纸板用料面积、抗压强度和托盘利用率（即集装箱空间利用率）结合起来，比较科学。并在实践中收到了明显的效果。特别是他们发明了一整套的设计图表，能迅速选择纸盒、纸箱的最佳形状和尺寸。以及纸盒在纸箱中和纸箱在托盘上的最佳排列形式，能起到减少用料面积、降低纸板克重、节约运输成本等实际效果。     

间隙切割压痕线对纸箱抗压强度的影响

通过对瓦楞纸箱进行抗压强度试验,分析常用于展示性纸箱的展示性结构要素对于纸箱抗压强度的影响,比较不同尺寸、位置、形式的间隙切割压痕线对纸箱的影响.试验结果对于展示性瓦楞纸箱的结构设计有一定的参考价值.     

一种异形多边形瓦楞纸箱的抗压性能研究

在传统瓦楞纸箱上增加了切角结构,以构成适用于衬垫外箱一体式快装包装箱的异形多边形瓦楞纸箱。通过试验研究了切角结构对纸箱抗压强度的影响,比较了不同切角尺寸、切角角度与切角数量对纸箱抗压强度的影响。结果表明:在其他结构参数保持不变的情况下,纸箱抗压强度在一定范围内随着切角长度的增加而增大;切角角度越接近45°,抗压强度越大;切角数量越多,抗压强度增加越明显。试验结果为该一体式快装包装箱的结构设计提供了理论依据,对利用切角提高纸箱抗压强度的结构设计也有一定参考价值。     

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。     

免胶带可自锁的瓦楞纸箱结构设计

目的 针对现有快递包装普遍使用胶带封箱及生命周期短等问题,提出一种免胶带封箱可自锁且可多次使用的新型瓦楞纸箱设计方案.方法 首先确定包装材料;接着进行创新性包装结构设计,重点设计免胶带封箱及自锁结构的可靠性;在此基础上确定纸箱多次使用的工艺流程;最后利用验证试验及有限元仿真对纸箱进行性能分析.结果 自由跌落试验结果表明提案纸箱在多次使用过程中具有良好的封箱强度;跌落仿真结果表明提案纸箱可吸收约40％的外部冲击载荷,具有良好的缓冲性能;空箱抗压仿真可知提案纸箱的最大抗压强度为3236 N,较普通开槽箱抗压性能提升约42％.另外,提案纸箱较普通开槽箱可降低约60％的生产成本.结论 提案纸箱具有免胶带封箱、自锁防盗启、生命周期长、保护性能好、生产成本低等优点.     

基于人工鱼群和模拟退火算法的电商快递纸箱规格优化

目的 对快递纸箱规格优化进行研究,在满足商品对纸箱需求和不增加纸箱规格种类的前提下,达到尽可能减少包装材料使用量的目标.方法 根据商品对快递纸箱的实际需求,以瓦楞纸使用总量最小化为目标函数,以商品和纸箱规格的匹配关系为约束条件建立优化模型.使用人工鱼群与模拟退火算法融合的求解算法对模型求解.结果 在仿真实验中,使用文中提出的建模求解方法得到的纸箱规格优化方案较中国邮政现行纸箱规格体系瓦楞纸使用量节省了23％,而采用k-means聚类分析得到的纸箱规格优化设计方案中瓦楞纸使用量仅节省了11％.结论 该方法可以满足商品批量小、种类多、尺寸各异、动态更新的电商环境下快递纸箱规格优化的需求,有助于改善快递行业包装过度使用的现状.     

改进瓦楞纸箱包装抗压强度的几种方法

本文结合工程实践提出了若千用以改善纸箱包装抗压强度的方法。文章首先分析了纸箱尺寸、纸箱容器使用的流通环境等因素对纸箱抗压强度影响的特点,指出从板状结构屈曲的角度提升纸板挺度和通过内衬垫设计与材料等措施以提升纸箱包装的承载能力,具有很好的工程指导意义。     

瓦楞纸箱系统设计软件的研究与开发

研究了在产品进行缓冲包装设计后,在已知产品缓冲包装后的尺寸、包装件的运输条件以及不同瓦楞纸板的强度参数的基础上进行瓦楞纸箱系统设计的理论,并进行软件的开发,目标是在输入已知条件后通过软件求得纸箱的型号、参数和结构尺寸.     

计算机辅助互楞纸箱设计

介绍研制的软件CADCB,采用人机交互式对话操作方式,能迅速地依据用户要求选择出最佳纸箱结构造型,精确地计算出该纸箱结构尺寸,并能进行纸箱强度分析和排料方案设计等等。另外.数据图形的输入输出多样化,且配有可扩充的瓦楞纸箱数学模型库和图形库。     

Lightweight design of bus frames from multi-material topology optimization to cross-sectional size optimization

A comprehensive solution for bus frame design is proposed to bridge multi-material topology optimization and cross-sectional size optimization. Three types of variables (material, topology and size) and two types of constraints (static stiffness and frequencies) are considered to promote this practical design. For multi-material topology optimization, an ordered solid isotropic material with penalization interpolation is used to transform the multi-material selection problem into a pure topology optimization problem, without introducing new design variables. Then, based on the previously optimal topology result, cross-sectional sizes of the bus frame are optimized to further seek the least mass. Sequential linear programming is preferred to solve the two structural optimization problems. Finally, an engineering example verifies the effectiveness of the presented method, which bridges the gap between topology optimization and size optimization, and achieves a more lightweight bus frame than traditional single-material topology optimization.     

基于材料选型优化的金属-复合材料组合结构-声辐射优化

基于金属铺层假设,以结构材料属性和材料铺层数量为设计变量,建立了基于金属-复合材料的材料选型结构-声辐射优化设计模型。以钢-纤维增强复合材料组合结构为例,开展了多设计变量、多约束条件的结构-声辐射优化研究。最后,采用遗传算法进行求解,实现了结构材料的转换。数值算例表明,通过金属-复合材料组合结构的材料选型优化,可以有效降低钢-纤维增强复合材料结构的振动和声辐射。文中的研究方法为结构材料的分布优化提供了一种可行有效的思路。     

Shape, sizing optimization and material selection based on mixed variables and genetic algorithm

In this work, we explore simultaneous designs of materials selection and structural optimization. As the material selection turns out to be a discrete process that finds the optimal distribution of materials over the design domain, it cannot be performed with common gradient-based optimization methods. In this paper, material selection is considered together with the shape and sizing optimization in a framework of multiobjective optimization of tracking the Pareto curve. The idea of mixed variables is often introduced in the case of mono-objective optimization. However, in the case of multi-objective optimization, we still face some hard key points related to the convexity and the continuity of the Pareto domain, which underline the originality of this work. In addition to the above aspect, there is a lack in the literature concerning the industrial applications that consider the mixed parameters. Continuous variables refer to structural parameters such as thickness, diameter and spring elastic constants while material ID is defined as binary design variable for each material. Both mechanical and thermal loads are considered in this work with the aim of minimizing the maximum stress and structural weight simultaneously. The efficiency of the design procedure is demonstrated through various numerical examples.     

Simultaneous single-loop multimaterial and multijoint topology optimization

As the aerospace and automotive industries continue to strive for efficient lightweight structures, topology optimization (TO) has become an important tool in this design process. However, one ever-present criticism of TO, and especially of multimaterial (MM) optimization, is that neither method can produce structures that are practical to manufacture. Optimal joint design is one of the main requirements for manufacturability. This article proposes a new density-based methodology for performing simultaneous MMTO and multijoint TO. This algorithm can simultaneously determine the optimum selection and placement of structural materials, as well as the optimum selection and placement of joints at material interfaces. In order to achieve this, a new solid isotropic material with penalization-based interpolation scheme is proposed. A process for identifying dissimilar material interfaces based on spatial gradients is also discussed. The capabilities of the algorithm are demonstrated using four case studies. Through these case studies, the coupling between the optimal structural material design and the optimal joint design is investigated. Total joint cost is considered as both an objective and a constraint in the optimization problem statement. Using the biobjective problem statement, the tradeoff between total joint cost and structural compliance is explored. Finally, a method for enforcing tooling accessibility constraints in joint design is presented.     

Particle swarm-based structural optimization of laminated composite hydrokinetic turbine blades

Composite blade manufacturing for hydrokinetic turbine application is quite complex and requires extensive optimization studies in terms of material selection, number of layers, stacking sequence, ply thickness and orientation. To avoid a repetitive trial-and-error method process, hydrokinetic turbine blade structural optimization using particle swarm optimization was proposed to perform detailed composite lay-up optimization. Layer numbers, ply thickness and ply orientations were optimized using standard particle swarm optimization to minimize the weight of the composite blade while satisfying failure evaluation. To address the discrete combinatorial optimization problem of blade stacking sequence, a novel permutation discrete particle swarm optimization model was also developed to maximize the out-of-plane load-carrying capability of the composite blade. A composite blade design with significant material saving and satisfactory performance was presented. The proposed methodology offers an alternative and efficient design solution to composite structural optimization which involves complex loading and multiple discrete and combinatorial design parameters.     

Design and Optimization of Composite Automotive Hatchback Using Integrated Material-Structure-Process-Performance Method

The application of polymer composites as a substitution of metal is an effective approach to reduce vehicle weight. However, the final performance of composite structures is determined not only by the material types, structural designs and manufacturing process, but also by their mutual restrict. Hence, an integrated “material-structure-process-performance” method is proposed for the conceptual and detail design of composite components. The material selection is based on the principle of composite mechanics such as rule of mixture for laminate. The design of component geometry, dimension and stacking sequence is determined by parametric modeling and size optimization. The selection of process parameters are based on multi-physical field simulation. The stiffness and modal constraint conditions were obtained from the numerical analysis of metal benchmark under typical load conditions. The optimal design was found by multi-discipline optimization. Finally, the proposed method was validated by an application case of automotive hatchback using carbon fiber reinforced polymer. Compared with the metal benchmark, the weight of composite one reduces 38.8%, simultaneously, its torsion and bending stiffness increases 3.75% and 33.23%, respectively, and the first frequency also increases 44.78%.     

A method for selecting macro-scale structures with axially loaded members

This paper presents a method to support the selection of lightweight large-scale structures. The method enables the ranking of alternative structural forms, whose axially loaded members can resist to either instability failure or material yield. Unlike previous approaches for concept design, this work models buckling failure to assess the interaction between the choice of a structural form and the choice of the cross-section shapes of its constituents. Shape transformers and scaling factors are introduced to characterize the structural efficiency of alternative cross-sectional shapes. Such parameters are dimensionless and enable to measure the shape efficiency without specifying the details of the cross-section geometry. The approach eases optimization at the concept design stage and it permits to assess how the selection of the member cross-sections impacts the lightweight potential of the structural topology. The model is used to construct charts for optimizing and selecting alternative forms. The method is applied in an industrial setting in order to compare three different structural concepts for a particular design application. The case study identified the potential performance of three structural forms and gave insight into the selection of the parameters that most influence structural performance.     

基于变频率区间约束的结构材料优化设计

针对频率约束的结构材料优化问题,基于结构拓扑优化思想,提出变频率区间约束的结构材料优化方法。借鉴均匀化及ICM(独立、连续、映射)方法,以微观单元拓扑变量倒数为设计变量,导出宏观单元等效质量矩阵及导数,进而获得频率一阶近似展开式。结合变频率区间约束思想,获得以结构质量为目标函数、频率为约束条件的连续体微结构拓扑优化近似模型;采用对偶方法求解。通过算例验证该方法的有效性及可行性,表明考虑质量矩阵变化影响所得优化结果更合理。     

结构性能化设计工具在家具设计中的应用和比较

目的 结合迅速发展的数字技术，探索家具设计方法和制造手段的新范式。方法 在数字设计领域“强结构”设计思潮的影响下，运用以图解静力学分析法发展起来的几种计算机结构性能化设计工具，如Polyframe、3DGS、Millipede3D，以及Ameba等，在家具设计中尝试将主动式结构找形与家具设计相结合，探索数字化家具设计原理及方法。结果 运用不断更新的结构分析与生成工具，将传统的、自上而下的设计师主导式设计转为自下而上的生成式全新工作流程，也创造了更新的、更生动的家具设计语言和形式。结论 随着计算机技术的高速发展，运算式设计逐渐成为设计的重要方法之一。新的设计流程从底层逻辑上打破了由包豪斯倡导的标准化材料选型和结构选型的设计局限性，突破了传统意义上功能优先的国际主义设计样式。同时，通过运算技术进行的材料优化、力学优化能更好地回应节能环保的需要，形成大批量定制的新时代形式美学和建构美学。     

Enhancement of basalt FRP by hybridization for long-span cable-stayed bridge

This paper presents an enhancement method for basalt fiber-reinforced polymer (BFRP) and the corresponding design optimization for application in long-span cable-stayed bridge. Based on previous studies of long-span cable-stayed bridge with FRP cables, the limitations of BFRP cables were first clarified and potential enhancement methods were proposed from both material and structural design perspectives. The basic mechanical properties and fatigue behavior of BFRP and the related hybrid FRP were experimentally studied and the hybrid effect on enhancing both types of properties was assessed. To address the improvement of utilization efficiency of FRP cables, design optimization of various FRP cables were proposed in terms of material enhancement and structural design requirement of long-span cable-stayed bridges. The results show that hybridization of basalt and carbon fibers not only increase the overall potential strength and the modulus but also enhance the fatigue behavior in comparison to basalt FRP. Meanwhile, hybrid basalt fiber and steel-wire FRP exhibits higher initial modulus and maintain high failure strain. Furthermore, design recommendation of FRP cables proposed in terms of lower limit, upper limit of safety factors and practical consideration result in FRP cables achieving higher integrated performance compared to those by conventional design.