7075铝合金喷丸参数影响的数值仿真及实验研究

为探究7075铝合金喷丸加工过程中不同喷丸参数对于喷丸结果的影响,本文基于Abaqus软件对相应的喷丸过程进行了有限元仿真,观察不同喷丸参数对于表面残余应力分布、表面粗糙度以及表面三维形貌的影响,同时基于实验过程对相应的喷丸过程进行研究,并对仿真和实验所得到的结果进行对比,最终发现,虽然在具体数值上两者之间存在一定的差距,但在变化趋势上两者呈现较为明显的一致性。因此,可以认为两者的分析结果是较为可信的,同时得出在单纯调整弹丸尺寸和弹丸速度的条件下,表面残余应力和表面粗糙度两者难以同时兼顾,但是喷丸覆盖率的提高可以用降低生产效率为成本较好的兼顾这两方面。

“双高”背景下的高职院校专业实验室集群建设

特色高职院校建设计划旨在建成一批高水平高职院校和专业,培养一流的技术技能人才。这显然离不开专业实验室的支撑。在当前中国特色高职院校的关键特征和建设路径尚待明晰的背景下,如何开展专业实验室高水平建设,是“双高”建设亟需解决的一个关键问题。综合多方面分析,厘清高职院校现役实验室助力“双高”建设困境和现实诉求,指出其高水平建设的关键抓手和突破口是“集群建设”,并从理念、设备、队伍、机制四维度提出了集群建设策略。经实践应用,在专业实验室集群的架构设计、实验设备、实验队伍和运管机制建设上取得了阶段性成果,对即将启动“双高”的专业化实验实训基地建设具有一定的参考价值和借鉴意义。

一种高效能球形腔体焚烧祭祀炉的设计

为解决民间祭祀引发火灾和所产生的烟雾污染空气的问题,将凹面镜聚焦产生燃点的原理与中华传统文化相结合,设计出了一种高效能、少烟雾安全防火灾的球形腔体葫芦形焚烧祭祀专用炉。通过球形腔体炉与圆柱形腔体炉的比较,由几何学和光学原理,得出了球形腔体炉在球心处所产生的焦点个数的理论公式,温度T—时间t实验,验证了球形腔体炉的高效能性。给出了装配图,并对结构设计的优势进行了分析。

Entrance and Exit Defects During Coarse Pitch Orbital Drilling of Carbon Fiber Reinforced Plastic Plates

Formation of entrance and exit defects in coarse pitch orbital drilling(CPOD)of carbon fiber reinforced plastic(CFRP)plates was investigated.Deep observation on entrance and exit morphology shows tear and burr are typical defects.Meanwhile,tear is more obvious than burr,and more entrance tears emerge than exit tears.As one of the major causes of entrance and exit defects in CPOD,cutting forces were substaintially studied by contrast experiments.Then,the effect of cutting parameters on entrance and exit tear was qualitatively analyzed through a single factor test.Experiment results indicate that the variation of rotation speed has little influence on entrance and exit tear.Increasing tangential feed per tooth can enlarge entrance tear,but bring little effect on exit tear.By increasing axial feed pitch,the hole entrance and exit show severe tear.When revolution radius grows bigger and bigger,entrance and exit tear firstly decreases,and then increases.Finally,the models of tear and delamination during CPOD of CFRP were established,the formation mechanisms of entrance and exit defects were revealed,and the control strategies were accordingly put forward.

新工科背景下地方高校自动化专业人才培养质量提升路径探索

为了适应新工科建设的要求,推动地方高校自动化专业人才培养质量的提升,培养具有高素质的复合型新工科人才,对南京晓庄学院自动化专业人才培养进行改革,探索提升自动化专业人才培养质量的路径。

Influence of Coolant on Chip Forming in Gun⁃Drill Based on Fluid⁃Solid Coupling Method

Chip shape is one of the important factors that affect the processing quality of the deep hole.The flow field of 17 mm standard gun-drill is simulated by taking the coolant pressure as a single factor variable,and the influence of coolant pressure on chip forming is discussed by combining with experiments in this paper.The results show that at the initial stage of chip forming,the flow of cutting fluid will intensify the lateral crimp of chips,and then affect the crimp radius of the chip and the number of turns of the crimp screw.The lateral crimp degree increases first and then decreases with the increase of coolant pressure,and the crimp degree is the smallest at 3 MPa.In addition,during the chip removal process,the stream shrinking in the flow field is the main influencing factor that drive and force the chip to break again,and their influence on the chip removal and chip breaking is proportional to the coolant pressure.

Methods for Reducing Interface Aperture Inconsistency During NC Orbital Milling of Aircraft Laminates with Coarse Pitch

The methods for reducing interface aperture inconsistency are studied in NC orbital milling(NCOM)of CFRP/Ti6Al4V laminates with coarse pitch.Comparative experiments show burr,aperture inconsistency and error are typical interface defects.Meanwhile,aperture inconsistency and error are more serious than burr in NCOM with coarse pitch.As one of the major causes of interface defects,axial force and radial force are intensively studied.Based upon the machining principle of orbital milling(OM)and the actual hole-making condition in laminated structures,NCOM experiments with coarse pitch are conducted on CFRP/Ti6Al4V laminates under different cutting conditions.Then,the effects of interlayer clamping,minimal quantity lubrication(MQL),twice milling instead of reaming,and interlayer speed change on interface aperture are analyzed.Research shows that interlayer clamping,interlayer speed change and MQL can effectively reduce out-of-tolerance of interface aperture.When making holes of different diameters with one cutter,axial feed has a greater effect on interface aperture precision than tangential feed.When making holes of the same diameter with different cutters,small diameter cutter will reduce interface aperture precision in a single processing.But the method of“twice milling instead of reaming”can improve the aperture precision effectively.

基于模内转印工艺的笔记本电脑主机上盖注塑模设计

根据笔记本电脑主机上盖塑件的结构特点,设计了基于模内转印工艺的热流道注塑模。针对IMR工艺的要求,设计出一套薄膜定位、吸附、移动机构;模具采用动定模倒装模具结构、热流道潜伏式浇口从塑件内部进胶以及斜顶侧向抽芯成型倒扣设计,有效解决了塑件成型可能出现的质量问题。