三合一竹节纱提花织物的开发生产

利用精梳棉、细旦涤纶、Modal三合一混纺竹节纱可开发高档面料,文章具体论述了整经、浆纱和织造工序的生产工艺及注意事项。     

某型发动机喷管-排气管系统建模方法

基于有限元分析法,研究某型发动机喷管-排气管系统建模方法.喷管的管束组件由多根螺旋管焊接而成,空间结构复杂,建立有限元模型难度大.将喷管沿轴线方向分为4段建模,采用多层各向异性壳单元模拟喷管管壁,通过偏转单元坐标x轴模拟螺旋角度.基于上述模型的模态分析与试验结果符合较好,模型可以用于振动分析.     

坦克机动性虚拟试验研究

主要研究了虚拟环境中军用车辆特别是坦克机动性虚拟试验时动力学模型的建立，建立了虚拟环境下坦克的实时动力学模型，并且描述了整个虚拟试验视景仿真系统的组成及其实现过程。     

Modal/细旦涤纶/羊绒三组分纱的纺制及成纱性能

利用Modal、细旦涤纶、羊绒三种纤维原料以不同的组分比进行成纱,探讨了其纺制加工工艺,并分别对不同混比的纱线性能进行测试。通过比较和分析,得到使纱线的各项性能优良的最佳混纺比。     

On quasi-static crushing of thin-walled steel structures in cold temperature: Experimental and numerical studies

The aim of the study reported herein was to investigate the effects of low temperatures on the crushing characteristics of steel plated structures. The motivation of this study is for the analysis of ship collisions in Arctic waters. A series of tensile coupon tests were performed to examine their material behaviour at low temperatures, and then quasi-static axial crushing tests were carried out on thin-walled square tubes. The test tubes were made of ASTM A500-type carbon steel, and both the tensile coupon tests of the material and the crushing tests of the tubes were performed in a liquid nitrogen cooled chamber. To reflect the conditions of the Arctic environment more realistically, the tensile coupon tests of the material were also carried out in a dry-ice cooled chamber. LS-DYNA nonlinear finite element method simulations applying a practical approach of modelling techniques were performed to investigate the structural crashworthiness of the thin-walled steel tubes numerically. The tests in the liquid nitrogen cooled chamber showed that the fracture strain of the material was not affected (reduced) by temperatures as low as −80 °C, although fracture strain was significantly reduced below −100 °C. The fracture strain results obtained in the dry-ice cooled chamber, however, show this strain to be affected (reduced) by low temperatures even between 0 °C and −80 °C, which is equivalent to the Arctic environment. It was also observed that fracture occurs in thin-walled tubes under crushing loads at low temperatures. The LS-DYNA computations also detected the fracture behaviour of test tubes in cold temperatures in a relevant way.     

自主研发实验设备,创建高水平的示范实验室

本文介绍了化工基础实验中心针对实验设备存在的一些问题,发挥实验指导老师的积极性,自主研发了系列实验教学设备的做法,并对自主研发实验设备的主导思想和所取得的成效进行了探讨。     

能源工程及自动化专业实验教学改革的探索与实践

专业实验课是高等学校的一门重要的基础课程,是提高学生动手能力,培养多种综合素质的重要环节,传统的实验教学方式存在较多弊端。华南理工大学在学科建设中借鉴了各方面的宝贵经验,按照专业培养目标,制定了合理的专业实验内容,根据专业实验课程的授课经验,提出了改进实验教学方式的新措施,并通过实践取得了良好的效果。     

考虑温度影响的排气系统断裂原因仿真分析

针对某汽车排气系统在使用中发生断裂故障的现象,采用有限元方法,考虑实际工况中温度的影响,对排气系统进行热模态与热疲劳性能仿真分析。得出在高温载荷作用下,排气系统的模态频率有所下降,某阶模态频率下降至发动机激励频率附近。排气系统在高温使用工况下的疲劳寿命大幅下降,且疲劳寿命最小处与实际断裂位置相同。得出了高温环境对排气系统疲劳性能有重要影响,而结构中存在的共振现象进一步加剧了排气系统的疲劳失效,确定了排气系统断裂故障产生的主要原因。     

Defecting From the Gutenberg Legacy: Employing Images to Test Knowledge Gaps

Education‐based knowledge gaps are well‐documented across countries, media platforms, and content. Without exception, knowledge is measured through words not images. Given the centrality of sight in the natural history of Homo sapiens, the extraordinary visual acuity of humans, and the proliferation of screen‐based visual media environments in contemporary life, an experiment was conducted to test the knowledge gap visually. Participants watched 8 audiovisual news stories. Simple recognition of story details and comprehension of that information were tested in verbal and visual modalities. Results offered the first confirmation of the knowledge gap in visual terms. Yet, gaps were significantly smaller employing visual than verbal measures, pointing to the need for continued efforts to develop visual measures for future memory studies.     

基于自激励的数控机床模态参数提取方法研究

提出了一种基于自激励的数控机床模态参数提取方法,利用该方法对XHK5140机床进行了实验模态分析,得到该机床的前4阶模态参数,并且将其和计算模态分析结果进行比较,验证了该方法的有效性。解决了传统模态实验设备难以激励大型数控机床的问题。