基于NX PDW和Dynaform的电瓶箱加强板级进模快速设计

CAD(Computer aided design)和CAE(Computer aided engineering)相结合的先进模具设计技术,能够显著提高冲压模具设计效率和设计质量,是现代模具设计的发展方向。以一款汽车电瓶箱加强板多工位级进模设计为例,在分析零件结构特征确定成形工艺的基础上,应用西门子级进模设计模块(NX PDW),快速实现了加强板级进模结构的详细设计。同时,针对加强板弯曲成形过程中可能出现的回弹、起皱、破裂等缺陷,应用冲压成形Dynaform模拟软件进行分析验证,能够确保所获得模具结构的合理性。经验证,该设计方法可为同类零件的级进模快速设计和验证提供参考。

Optimization Design of Minimum Total Resistance Hull Form Based on CFD Method

In order to reduce the resistance and improve the hydrodynamic performance of a ship, two hull form design methods are proposed based on the potential flow theory and viscous flow theory. The flow fields are meshed using body-fitted mesh and structured grids. The parameters of the hull modification function are the design variables. A three-dimensional modeling method is used to alter the geometry. The Non-Linear Programming(NLP) method is utilized to optimize a David Taylor Model Basin(DTMB) model 5415 ship under the constraints, including the displacement constraint. The optimization results show an effective reduction of the resistance. The two hull form design methods developed in this study can provide technical support and theoretical basis for designing green ships.

The Design of Form Milling Cutter as the Curve of the Back of Tooth Is Logarithmic Spiral

Form milling cutter is built-for-purpose cutter which process the form surface, for example, usually process male and female circular arc face and form trench and so on. From the traditional concept, form milling cutter is divided into pointed tooth and relieving follow its structure. Relieving shaped cutter is more convenient than pointed tooth milling cutter, because only its rake face is needed to grind after it turn into blunting, so the current books which are used in college almost select relieving shaped cutter in order to introduce how to design the form milling cutter.The curve of the back of tooth of relieving cutter is the transversal which is formed by the rear face of tooth in the end cut plane of the milling cutter. In the past, because of the limit of the manufacturing technology, the curve of the back of tooth is often selected Archimedes’ curve, in order that the shovel-nose tool acquire the uniform motion when the cutter shovel the back, in other word, the rear face of the milling cutter rotate its axis by the new cutting lip, in the same time, it move uniformly to the axis in order to form the surface. Although this curve of the back of tooth meet the fixedness of the form of blade around grinding the cutter, the rear angle of the dot of the cutting lip don’t keep fixedness. With the development of the modern manufacturing technology, the unmanageable problem of many complex curves is already easily solved. So it is need to study the optimum profile of the curve of the back of tooth in theory, and study the design theory of the relieving shaped cutter under the condition of new manufacture, in order to ensure that the rear angle of the dot of the cutting lip keep fixedness after the relieving shaped cutter is grinded. The paper derive the curve profile of tooth of the form cutter and the modifier calculation formula of the profile of the cutter edge from the definition of the rear angle of the cutter, which establish the foundation for the precision design and manufacture of other form cutter.

Forming-Precision-Driven Structure Design of Hydraulic Press: Methodology and Case Study

The structure stiffness of presses has great effects on the forming precision of workpieces, especially in near-net or net shape forming. Conventionally the stiffness specification of presses is empirically determined, resulting in poor designs with insufficient or over sufficient stiffness of press structures. In this paper, an approach for the structure design of hydraulic presses is proposed, which is forming-precision-driven and can make presses costeffective by lightweight optimization. The approach consists of five steps:(1)the determination of the press stiffness specification in terms of the forming precision requirement of workpieces;(2)the conceptual design of the press structures according to the stiffness and workspace specifications, and the structure configuration of the press;(3)the prototype design of the press structures by equivalently converting the conceptual design to prototypes;(4)the selection of key structure parameters by sensitivity analysis of the prototype design; and(5)the optimization of the prototype design. The approach is demonstrated and validated through a case study of the structure design of a 100 MN hydraulic press.

The Construction of Locally D-Optimal Designs by Canonical Forms to an Extension for the Logistic Model

Logistic regression models for binary response problems are present in a wide variety of industrial, biological, social and medical experiments;therefore, optimum designs are a valuable tool for experimenters, leading to estimators of parameters with minimum variance. Our interest in this contribution is to provide explicit formulae for the D-optimal designs as a function of the unknown parameters for the logistic model where q is an indicator variable. We have considered an experiment based on the dose-response to a fly insecticide in which males and females respond in different ways, proposed in Atkinson et al. (1995) [1]. To find the D-optimal designs, this problem has been reduced to a canonical form.

地外建造研究进展与科学技术挑战

随着深空科学与深空探测技术的不断发展,NASA、ESA以及其他一些国家纷纷提出地外空间中长期驻留设想及其地外建造相关计划。该文梳理了国内外地外建造相关战略,系统分析了地外建造的概念内涵及其发展;总结了地外建造结构设计、材料制备和建造工艺装备三方面研究进展;进而分析指出地外建造关键科学技术挑战。期待更多的学者关注地外建造这一新的研究领域,为我国深空探测贡献土木工程学科智慧。

可持续理念下藤编家具形态仿生设计研究

目的为进一步提升产品的可持续性应用价值,提出了可持续理念下产品形态仿生设计路径,以藤家具为研究对象,探寻藤编家具的可持续设计创新。方法首先,采用文献研究与田野调查相结合的方法,梳理国内外藤编家具的设计研究现状,总结藤编家具行业的现存问题;其次,利用问卷调研法确定用户需求及仿生对象,借助AHP(层次分析法)决策分析原理选择最佳的仿生设计元素,并应用可持续设计策略对藤编家具进行设计创新;最后,采用LCA(生命周期评价)进行设计方案的可持续性评估,确定了综合水平高的方案。结论通过构建可持续理念下产品形态仿生设计路径,提出产品领域应用的可持续设计策略,并应用于藤编家具设计实践,结合用户调查和专家打分,从元素提取、方案设计和方案评估三个方面验证路径的可行性及有效性,为藤编家具的可持续创新提供新思路。

Smoothing Parametric Design of Addendum Surfaces for Sheet Metal Forming

The manual design of addendum surfaces on common CAD platforms is very tedious which requires many trialscorrections,which will certainly a ect the construction e ciency and quality of addendum surfaces,and then a ect the formability and quality of the workpiece in the process of sheet forming.In this paper,an automatic procedure based on parametric design method is proposed for the rapid construction of the addendum surfaces.The kernel of the parametric method is constructing boundary curves based on the shape of surfaces of workpiece and designing guide curves based on Hermite curve interpolation.By some simple parameters,the shape of the addendum surfaces could be controlled and adjusted easily.In addition,a minimum energy optimization method is employed to further optimize the constructed addendum surface.A finite element analysis for the sheet forming process is performed to evaluate the forming quality of constructed addendum surfaces.The instance illustrates that the addendum surface constructed by the proposed method could ensure both the overall smoothing of surfaces and the final forming quality,and it has a good e ect on springback after forming.This research proposes a smoothing parametric design method for addendum surfaces construction which could construct and optimize addendum surfaces rapidly.

The Design of a Graphical User Environment for Numerical Simulation of Powder Forming Processes

As computer simulation increasingly supports engine er ing design and manufacture, the requirement for a computer software environment providing an integration platform for computational engineering software increas es. A key component of an integrated environment is the use of computational eng ineering to assist and support solutions for complex design. Computer methods fo r structural, flow and thermal analysis are well developed and have been used in design for many years. Many software packages are now available which provi de an advanced capability. However, they are not designed for modelling of powde r forming processes. This paper describes the powder compaction software (PCS_SU T), which is designed for pre- and post-processing for computational simulatio n of the process compaction of powder. In the PCS_SUT software, the adaptive analysis of transient metal powder forming process is simulated by the finite element method based on deformation theories . The error estimates and adaptive remeshing schemes are applied for updated co -ordinate analysis. A generalized Newmark scheme is used for the time domain di scretization and the final nonlinear equations are solved by a Newton-Raphson p rocedure. An incremental elasto-plastic material model is used to simulate the compaction process. To describe the constitutive model of nonlinear behaviour of powder materials, a combination of Mohr-Coulomb and elliptical yield cap model is applied. This model reflects the yielding, frictional and densification char acteristics of powder along with strain and geometrical hardening which occurs d uring the compaction process. A hardening rule is used to define the dependence of the yield surface on the degree of plastic straining. A plasticity theory for friction is employed in the treatment of the powder-tooling interface. The inv olvement of two different materials, which have contact and relative movement in relation to each other, must be considered. A special formulation for friction modelling is coupled with a material formulation. The interface behaviour betwee n the die and the powder is modelled by using an interface element mesh. In the present paper, we have demonstrated pre- and post-processor finite elem ent software, written in Visual Basic, to generate the graphical model and visua lly display the computed results. The software consist of three main part: · Pre-processor: It is used to create the model, generate an app ropriate finite element grid, apply the appropriate boundary conditions, and vie w the total model. The geometric model can be used to associate the mesh with th e physical attributes such as element properties, material properties, or loads and boundary conditions. · Analysis: It can deal with two-dimensional and axi-symmetric applications for linear and non-linear behaviour of material in static and dyna mic analyses. Both triangular and quadrilateral elements are available in the e lement library, including 3-noded, 6-noded and 7-noded (T6B1) triangles and 4 -noded, 8-noded and 9-noded quadrilaterals. The direct implicit algorithm bas ed on the generalized Newmark scheme is used for the time integration and an aut omatic time step control facility is provided. For non-linear iteration, choice s among fully or modified Newton-Raphson method and quasi-Newton method, using the initial stiffness method, Davidon inverse method or BFGS inverse method, ar e possible. · Post-processor: It provides visualization of the computed resu lts, when the finite element model and analysis have been completed. Post-proce ssing is vital to allow the appropriate interpretation of the completed results of the finite element analysis. It provides the visual means to interpret the va st amounts of computed results generated. Finally, the powder behaviour during the compaction of a multi-level component is numerically simulated by the PCS_SUT software, as shown in Fig.1. The predict ive compaction forces at different displacements are computed and compared with the available experimental

照明系统中配光元件反射-吸收损耗的计算

在照明光学设计中,光通量利用率是配光元件的一个重要评价指标。基于菲涅尔公式,建立了配光元件反射-吸收损耗的理论模型,并探讨了其适用范围。利用该模型分别计算了自由曲面平凸透镜和全内反射透镜的反射-吸收损耗,并与软件仿真和实验实测的光通量损耗数值进行了对比。研究发现,该理论模型的计算数值与光学软件的仿真结果高度相符,点光源60°平凸准直配光透镜和全内反射透镜的透射率绝对误差分别为0.7%和0.14%,考虑装配误差影响之后,此数值与实验测量结果也基本匹配。利用本研究所建的反射-吸收损耗模型,在照明光学设计中,无需进行软件仿真和实验测试,即能快速而精确地预测出各类配光元件在各个光学表面上的反射损耗和材料吸收损耗,为配光元件的性能评价、结构选择和优化定型提供参考依据。

历届奥运会徽设计形态演变研究

目的奥运会徽的设计有时间上的规律性和空间上的不可预计性,形成了既系统又独立的形态风貌。系统地研究奥运会徽的设计演变,为设计师在国际大型活动的标徽设计中提供理论参考。方法通过历届冬夏两季奥运会徽进行设计要素解析,总结奥运会徽的设计原则,分析会徽形态演变方式,并提出了对未来会徽形态的预想。结论会徽的设计一直以民族文化与国家意志为依托,强调传统与时代、传承与发展,是地域文化个性与人类文明共性的结合,但鉴于其商业运作模式的考量,设计形态虽然受媒介和技术的影响发生模态变化,但会徽传递的信息范式不会改变。

强内涵 促发展——现代中医医院建筑形态布局研究

结合中医医院建筑的发展历程和时代需求,对我国当今中医医院建筑形态布局的类型进行归纳,分析总结各类形态布局特点,探讨中医医院建筑形态布局的设计方法,提出与自然环境有机结合、传承创新建筑文化、功能布局高效便捷、弹性设计等设计策略,为现代中医医院建筑形态布局设计提供参考。

基于改性PP成型的工控机电路板支撑架注射模设计

针对工控机电路板支撑架大型塑件的成型,选用了一种玻纤改性增强聚丙烯(PP)复合材料用于塑件的注射成型。模具结构为三板模结构,分3次开模打开。为保证塑件模腔充填均衡性、饱满性而设计了两个点浇口用于模腔的浇注。针对塑件二级子特征较多,特别是异型螺柱深筋位较多的特点,设计了多个局部镶件用于这些局部特征的成型,在提高局部成型镶件强度的同时,降低了这些成型件的加工难度。针对模腔局部位置排气难点,设置了多个透气镶件以增强排气。设置了锁扣机构、定距拉杆机构用于模具的开模闭模控制;设计了弹料机构用于流道废料的可靠脱模、定位机构以确保塑件的成型精度和模具工作寿命;3个滑块机构用于塑件侧壁直壁及直壁上侧孔的成型与脱模。模具结构形式合理,成型件便于加工且实用可靠,能为同类模具设计提供有益借鉴。

既有中小型酒店更新改造设计研究——以济南东源大厦为例

随着经济增长与社会发展,城市更新的需求不断加强,既有酒店建筑作为城市的重要构成,其更新改造随之提上日程。酒店建筑的改造涉及的学科范围广泛,门类众多,其改造设计策略仍待于实践中持续探索。文章选择了济南市东源大厦改造更新的实践案例,从院落环境升级,外部形态更新,内部功能改造等方面分析,对现有中小型酒店建筑更新改造的设计方法进行探索,提出场地景观重新规划、对立面入口更新、优化交通流线、公共空间重组、房型升级的具体改造方法,使其融入城市环境,满足使用需求,为更多此类工程提供一个思路与借鉴。

专业篮球鞋鞋底综合性能要求与形态设计研究

随着全民运动的全面开展,高性能、专业化的篮球鞋也随之兴起并得到越来越多的关注。专业篮球鞋功能性的高低直接取决于其防滑、缓震、耐磨等性能。本文详细探讨了专业篮球鞋对鞋底性能的各方面要求与研究现状,提出基于综合性能提升的篮球鞋鞋底形态设计方案,如基于支撑性与耐久性的鞋底形态设计、基于防滑性的鞋底形态设计等,并探究了专业篮球鞋现代化、智能化的设计方法与技术,以促进各项鞋底设计方案的实现,丰富专业篮球鞋产品设计的创新方法。

基于微信小程序的智慧校园平台设计

福建农业职业技术学院智慧校园平台的设计旨在提升校园管理水平、优化教学质量和实现学生个性化服务。依托微信小程序,整合学校已有的各类信息资源,如学生信息、教师信息、教学资源、教学设施等,根据教师和学生的需求分析,从平台构建思路、平台结构、功能模块、数据库和功能应用等5个方面进行设计,确定了以“师生共长,服务便利”为核心的平台建设方案,为师生员工开发便利的信息服务平台,进一步优化教学管理、教学质量和学生服务,在增强学生个性化服务体验的同时,提升校园管理水平。

一种海洋自升式修井平台船型分析

针对渤海海域油气开发中自升式修井平台的船型设计,进行系统分析。从桩腿数量维度出发,考虑波流载荷、风载荷和平台重力的共同作用,通过有限元数值模拟软件,建立自升式修井平台的仿真模型,计算不同方向角下平台的波流载荷、桩腿位移和抗倾力矩等评价指标,综合对比分析三桩腿和四桩腿两种不同船型的设计特点,以揭示各自在平台方案、预压载能力和稳定性等方面的特点。研究结果发现,四桩腿平台在舱内设备布置、预压载能力和抗倾稳性方面具有明显优势,特别是在单桩失效情况下,四桩腿平台的稳定性和安全性更高。研究结论对自升式修井平台的设计优化具有重要的指导意义,为进一步提升平台的安全性和高效性提供理论依据。

承续共新:传统器物美学与产品形态设计课程融合探析

中国传统器物美学是中华文化的瑰宝,为现代产品形态设计提供了丰富的灵感。将传统器物美学作为产品形态设计课程的核心主题,通过多维度的教学内容、多元化的教学方法以及多渠道的教学模式,引导学生从优秀传统文化中汲取灵感,将传统美学元素融入现代设计中,实现传承与创新。同时,结合产品构型方法、细节文法和构型思维进行实践实训,提高学生的审美和人文素养,推动传统器物美学在传承中焕发新活力。

基于学生能力达成的“食品工厂课程设计”形成性评价机制研究与实践

通过完善过程评价方式与手段,明确评价结果对课程目标的支撑,构建了基于学生能力达成的“食品工厂课程设计”形成性评价机制,实现了学生针对复杂工程问题进行课程设计的全程跟踪与反馈,以及学生能力达成程度和实践教学培养质量的有效评估。