Nonlinear Finite Element Analysis and Optimum Design of Spot-Welded Joints and Weld-Bonded Joints

Resistance spot welding and hybrid weld bonding have wide applications in the body work construction within the automobile industry. The integrity of the spot welds and applied adhesives determines the body assembly rigidity and dynamic performance. Incorporating contact nonlinearity and geometric nonlinearity, finite element analysis (FEA) have been carried out to investigate the structural stiffness and strength of both spot-welded and weld-bonded assemblies. Topology optimization has been performed to reveal the distributions of material effectiveness in the overlap regions and suggest a feasible method for removing underutilized material for weight reduction. Design optimization has been conducted with an aim to reduce the maximum von Mises stress in the assembly to minimum by choosing optimum values for a set of design variables, including the weld spacing, weld diameter and overlap width.

Optimization design of resistance spot welding parameters of magnesium alloy

By means of the quadratic regression combination design process, the regression equations of nugget diameter and tensile shear load of spot welded joint were established. Effects of welding parameters on the nugget diameter and the tensile shear load were investigated. The results show that effect of welding current on nugget diameter is the most evident. And higher welding current will result in bigger nugget diameter. Besides, interaction effect of electrode force and welding current on tensile shear load is the most evident compared with others. The optimum welding parameters corresponding to the maximum of tensile shear load have been obtained by programming using Matlab software, which is 4, 7 kN electrode force, 28 kA welding current and 4 cycle welding time. Under the condition of the optimum welding parameters, the joint having no visible defects can be obtained, nugget diameter and tensile shear load being 6. 8 mm and 3 256 N, respectively.

一种消除hot spot现象的LED背光设计

随着高亮度LED晶片、导光板成型技术、光学薄膜(反射膜、散射膜、增亮膜)等制作技术的发展,加上不断创新的LED背光模组光学系统设计,以及LED背光市场的巨大需求,大大推动了LED背光技术水平不断向前发展。这里设计了一种消除hot spot现象的背光设计。结果可知:达到设计效果的改进关键仅是在导光板的入光面上贴上一条有微棱镜结构的膜片,从而使入射至导光板的光束角度变大,达到良好的均匀光效果。让增加相邻LED间距而不出现hot spot现象成为可能,这一研究对于消除hot spot所带来的均匀性过差问题具有一定的意义。

SIMULATION OF THE SPOT SIZE AT DISPLAY TUBE SCREEN

Based on a description of several methods of how to determine the resolutionat display tube screen,and the transfer relation between them,this paper lays emphasis ondiscussing the spot size at display screen by way of the electronic optic CAD.A set of pre-cise and reasonable calculation models are presented,and thomputcr simulation ismade.It is shown that the calculation results coincide with the experimental ones.

Crime Prevention in Ethnic Areas Focusing on Crime Prevention through Environmental Design

The purpose of this study is to consider crime prevention measures in ethnic areas focusing on Crime Prevention through Environmental Design (CPTED) by an analysis of crime data and field survey. In this study, it was found that the main type of foreign crime that occurred in the research area was violence, and crimes committed by Koreans, which were mainly violence and crimes such as burglary, theft, robbery, and sexual offences, occurred steadily. Because it was found that crimes were related to the urban planning elements comprised of land use such as traditional market, inn, pub, and complicated space structure and the architectural design for natural surveillance and security facilities such as CCTV, lighting, alarm, and target hardening device, a new strategy for crime prevention design should include street environmental management, improvement of commercial facilities, and reinforcement security device of each buildings has to be spread through support of policy. In conclusion it was thought that CPTED would be a valuable measure to prevention crime and support community activities in ethnic area as expecting an improvement of physical environment and resident participatory for safer community.

解析Robe's Spot 1200E AT电脑灯

详细介绍Robe’s Spot 1200EAT电脑灯的性能测试内容及相关参数情况。

Analysis of the effect of geometrical parameters on fatigue performance of spot-weld joint for ultra-high strength steel

This paper studied the spot welding structure of ultra-high strength steel 22MnB5.ANSYS software was adopted to simulate its static strength;BS5400 algorithm was used to calculate the fatigue life;and the grouping method was used to test the fatigue performance of tensile shear spot weld specimens.The simulation results were in good agreement with the experimental values.Based on the validation of the simulation method,influences of different structural parameters on static strength and fatigue life were explored by adopting single factor.The results showed that within the selected structure parameter range,increase of the sheet thickness,nugget diameter,sheet width and overlapping length can lead to longer fatigue life.Besides,the fatigue life of spot weld took on a linear relationship with the overlapping length,a DoseResp relationship with the sheet thickness,and a single exponential decay relationship with the sheet width and the nugget diameter.Moreover,in order to estimate the impact from various parameters on the fatigue life of the specimens,the Taguchi orthogonal design method was applied in the simulation design.The simulating result indicated that influence of the sheet thickness on fatigue life was the most significant.In addition,the effects of nugget diameter,sheet width and overlapping length on fatigue life were reduced in turn.

PRACTICE AND KNOWLEDGE ABOUT RECONSTRUCTION DESIGN OF TRADITIONAL BUILDINGS AND GARDENS

In this paper,the author sums up some essential knowledge from the practiceabout rebuilding traditional buildings and gardens in which the author has been engagedrecently.The view points are that one should discard the dross and select the essential,re-tain the symbolic form,grasp the overall style,embody local characteristics and space outthe distance of time and space between the new and old buildings.Finally,the author con-siders that the traditional form of buildings should not be used indiscriminately at allplaces in modern times.

基于相关性分析法的文旅景区艺术创意设计优化研究——以12个文旅景区为例

艺术创意设计在文化传承和文化经济产业发展方面的作用日益加深,了解艺术创意设计能有效促进旅游消费者行为意向的生成,实现文化旅游景区的可持续稳定发展。以艺术创意设计为路径,收集相关案例,进行概况分析。提出当前我国文旅景区艺术创意设计的不足,运用相关性分析法对于文旅景区艺术创意设计进行研究。从特征深化、交叉融合、策略调整、规范完善四方面进行艺术创意设计优化引导,寻求具有艺术创意、创新特色的中国文旅景区新的发展模式,为文旅景区的发展提供一定的借鉴,促进文旅景区的持续升级与开发。

磁脉冲点焊焊枪的设计及仿真分析

目的根据现有平板线圈的不足,设计了一种用于自动化作业的磁脉冲点焊焊枪。方法采用有限元模拟方法对比分析了磁脉冲点焊焊枪线圈和现有平板线圈的性能差异,并对磁脉冲点焊焊枪线圈的结构进行了优化。结果当线圈工作部分高10 mm、宽4 mm时,焊枪线圈和平板线圈的最大电流密度、最大磁感应强度、最大洛伦兹力分别为3.142×10^(10)A/m^(2)和3.639×10^(10)A/m^(2)、19.40 T和21.69 T、5.149×10^(11)N和1.626×10^(12)N。当线圈工作部分宽4 mm时,随着高度由10 mm降低至4 mm,焊枪线圈的最大电流密度和最大洛伦兹力分别提升了27.56%和57.64%。当驱动能力接近时,焊枪线圈所产生的位移仅为平板线圈的13.09%。当焊枪线圈工作部分截面为10 mm×10 mm的方形时,飞板凸台在20μs时的速度仅为200 m/s;而当截面为ϕ5.6 mm的圆形时,飞板凸台在19.2μs时便产生237 m/s的速度。结论在工作部分的高度和宽度相同的情况下,焊枪线圈的性能要弱于现有平板线圈的性能。在宽度不变的条件下降低焊枪线圈工作部分的高度可以增大飞板的电流密度、洛伦兹力和速度,并且在性能相近的情况下,焊枪线圈工作部分所受应力要小于现有平板线圈所受应力。另外,将磁脉冲点焊焊枪线圈工作部分的截面由方形替换为相同面积的圆形,可以获得更优的焊接条件。

东兴市农旅融合产业发展研究

农旅融合发展能够有效整合自然资源和人文资源,促使旅游业与农业良性互动与深度融合,激活农村经济,实现乡村振兴。通过系统研究东兴市农旅融合发展滞后的原因,并提出相应策略。强化农村旅游发展规划,加强配套基础设施建设,打造农旅融合全产业链等举措,增强农旅融合发展动力,实现东兴市农旅深度融合发展,有效解决“三农”问题。

优化的高分辨率遥感影像变化图斑提取与检查工具集

高分辨率遥感影像变化图斑提取的自动化实现能为自然资源监测提供有力的技术支持。为提高变化图斑提取的自动化程度和准确率,基于ArcGIS平台面向对象的分析和设计方法,采用通用开发工具设计了变化图斑的提取和检查工具集。该工具集实现了变化图斑的自动提取、检查、编辑修正、整合与处理。经实际应用,证明该工具集能够高效准确地提取、检查和处理图斑数据,辅助相关人员快速及时、客观真实地获取地表变化情况,为自然资源变化监测提供有力技术支撑。

面向“互联网+”的旅游景区智能预约系统设计与实现

随着人工智能技术的发展,互联网与传统行业实现了深度融合,为其带来了前所未有的发展机遇。本文利用java技术设计实现了旅游景区智能预约系统,旨在提高旅游景区预约信息管理的简单化和便利化。系统具有良好的易用性和安全性,可以满足旅游景区预约管理的相关工作。

基于文献计量分析的中国被动式超低能耗建筑研究热点与趋势

为探索近年来我国被动式超低能耗建筑研究的热点和趋势,采用CiteSpace与VOSviewer基于中国知网和Web of Science作为中英文文献来源,搜索并提炼154篇中文核心及118篇英文核心有效文献进行科学知识图谱分析。研究结果表明,该领域的发展进程大致可划分为三阶段:发展阶段、增长阶段、延伸阶段,国内研究机构初步形成了较小团体的研究网络,但未形成大规模的研究团体。随着被动式超低能耗建筑的不断发展,多目标优化研究成为热点,其研究趋势也将更加注重针对当地气候和资源特点的定制化设计和优化,同时将更加注重实践应用和技术推广,以实现更加可持续、健康和舒适的居住环境。

基于三维建模和激光点云的建筑物目标监测系统

以提升目标监测效果为目的,提出基于三维建模和激光点云的建筑物目标监测系统。该系统首先利用感知单元采集目标激光点云数据,通过通信单元将数据传输到数据处理单元内,利用八叉树抽稀算法对建筑物目标激光点云数据实施简化处理,然后使用3DsMax三维建模软件构建目标三维模型,利用该模型进行实现建筑物目标监测,最后实验结果表明:系统采集的数据偏差小,点云抽稀率可达到30.5%,目标特征值监测偏差小于5%,可有效监测建筑物目标物体变化情况,监测性能良好。

粗铜锭表面随机选点钻样系统改造设计

为了提高粗铜锭钻样工作效率,保证粗铜锭钻样选点过程的合法合规,实现无人干涉自动化作业,确保进厂粗铜锭质量,对原人工钻样系统进行了改造。首先分析人工钻样存在的问题,在保留钻孔机的基础上,根据随机选点系统功能性指标要求,对系统方案实施构架、操作流程、子系统功能构架进行改造设计。经应用测试,改造后的随机选点系统具有可靠性高、安全性好、工作效率高等优点。

多维度视角下景区规划设计研究

景区是新时代城市建设和社会发展的重要组成部分,通过合理的规划设计,可提升城市形象,改善居民生活品质,促进文化传承,吸引游客,同时还能发挥生态调节和环境改善的功能。基于此,从多维度视角探索景区规划设计策略,旨在推动城市建设向着更加宜居、宜业、宜游的方向发展,为城市可持续发展贡献力量。

视觉传达设计在旅游景区形象设计中的作用研究——以齐云山景区为例

为了让旅游景区在竞争激烈的旅游市场中脱颖而出,以齐云山景区为例,深入探讨了视觉传达设计在旅游景区形象设计中的重要作用。通过分析齐云山景区视觉形象设计,提取区别于黄山景区、徽文化的显著特征并融入设计中,不仅能显著增强游客的游览体验和场景记忆,而且可以促进旅游纪念品的销售,为景区带来额外的经济效益,同时也能为其他景区形象设计提供实际指导和策略建议。

基于高精度激光光斑质心定位技术的教学实验设计

针对空间激光通信过程中激光捕获跟踪瞄准系统激光光斑高精度定位问题,提出一种基于Otsu联合加权最小二乘的激光光斑质心定位方法。该方法采用Otsu阈值分割实现激光光斑图像中目标光斑与干扰光斑的分离,采用加权最小二乘圆拟合,以迭代重加权方式进行光斑图像的最佳拟合,进而实现高精度的光斑质心提取。该文还设计了仿真教学实验,并基于MATLAB软件验证了所提算法的质心定位精度显著高于传统的灰度重心法的结论。该算法可实现亚像素级光斑质心定位精度,具有很好的抗噪性能。最后分析了仿真实验中不同因素对光斑定位精度的影响。

基于文旅融合背景下的旅游景区文创IP设计研究——以肇庆星湖景区为例

随着文旅融合深度发展,景区转型刻不容缓。本研究以肇庆星湖景区为例,探索文旅融合背景下的景区文创设计方法。通过对星湖景区用户的研究,IP形象设计、VIS视觉系统完善、线上智慧导览的创作实践,展现文旅融合背景下景区文创的设计研究路径。提出了景区用户定位不清、内容同质、系统性缺失、营销手段单一等问题,得到融入地域文化的景区IP、系统性视觉系统、智慧导览APP设计,最终构建“互联网+景区”线上线下相结合的“景区+旅游+文化”的新模式。