Ф168mm规格钢管的定径机孔型设计

在消化德方提供的工艺资料基础上,设计出了Ф168mm规格钢管的定径机孔型.     

Fuzzy-based optimised subset simulation for reliability analysis of engineering structures

This paper presents a numerical strategy for the efficient reliability assessment of engineering structures with random variables and fuzzy variables using fuzzy based optimised subset simulation (SS) approach. The proposed method relies on the performance function of the structure, which involves probability distribution functions and fuzzy variables for the modelling of the structural system. The values of the fuzzy variables for every alpha level are first obtained using the membership function. Therefore, the set values of the fuzzy variable bound the reliability of the structure, and this is evaluated using optimisation and efficient SS approach. The rationale behind the proposed strategy is to locate a failure domain or region where the objective function is minimised or maximised and compute the reliability using SS. The proposed algorithm in this study inherits the benefits of direct Monte Carlo approach in propagating the uncertainties associated with structural parameters but also demonstrate more robustness against the latter. The methodology can be applied to any engineering structures, and the applicability is demonstrated here, using a buried pipeline.     

移动式三维激光扫描系统在盾构隧道管片椭圆度检测中的应用

介绍对比了几种常用的地铁盾构隧道管片椭圆度检测方法,并在此基础上以GRP5000系统为例分析了基于移动式三维激光扫描系统的椭圆度检测的基本原理及内外业工作流程。通过实际项目检验,表明基于移动式三维激光扫描系统的地铁盾构隧道管片椭圆度检测方法具有优势。     

不同椭圆度的狭窄胆管与编织型支架耦合系统的生物力学性能

利用有限元法对编织型胆管支架在0%、5.26%和10.53%椭圆度的狭窄胆管内进行力学性能模拟,对比分析不同椭圆度和狭窄率对支架-胆管系统生物力学行为的影响。结果显示,在支架植入后的系统平衡状态下,胆管壁上等效应力分布随椭圆度和狭窄率的变化而不同;在支架冠顶丝线中部以及与其接触的胆管内壁上均有应力集中现象;椭圆度和狭窄率对支架扩张和贴壁性能的影响不大,支架在3种不同椭圆度和不同狭窄率的胆管内具有良好的扩张性和贴壁性能。不同椭圆度和狭窄率的胆管与支架的耦合模型的建立与分析,能进一步了解编织型支架的力学性能,可为其优化设计和临床选型提供重要的理论依据。     

90°厚壁弯管的应力分析与试验研究

应用ANSYS软件对受内压作用下的大型厚壁弯管进行了应力计算和分析,从而得到该弯管模型的应力分布规律,并结合相应的试验数据进行对比分析,验证了有限元分析结果的可靠性。     

螺旋埋弧焊管椭圆度的控制

介绍了钢管椭圆度超标对管道现场施工的影响,分析了螺旋埋弧焊管椭圆度超标的影响因素。针对螺旋埋弧焊管机组椭圆度的控制提出了可行的调控或消减措施,即通过优化成型调型工艺参数,改进预弯装置控制成型缝翘嘴,改进机械夹辊装置保证铣边质量等措施,有效控制螺旋埋弧焊管椭圆度超标,对改善螺旋埋弧焊管的制造质量具有一定的指导意义。     

GCr15SiMn钢环体的真空热处理及畸变分析

对山形和槽形GCr15SiMn钢环体进行了同炉真空淬火和低温回火试验,并做了畸变统计。结果表明：两种钢环体硬度均匀,为58～62 HRC;但畸变趋势不同,其中山形钢环体内外径收缩畸变量大于椭圆度变化,最大收缩畸变量为-0.44 mm;而槽形钢环体内外径涨缩畸变和椭圆度均较明显,且内外径涨缩量为-0.34～+0.43 mm,椭圆度为0.20～0.50 mm。     

回转窑和托轮位置的在线测量和调整实施*

2016年上半年来,我公司（Ф4.8 m×72 m） 3号回转窑2档单侧托轮时有脱空,且该处窑墩有晃动感,大齿圈震动大,窑体多处频繁掉砖,严重影响窑正常生产。同年9月我公司请武汉理工大学采用远距离测量窑中心线和托轮空间位置、测量筒体椭圆度及径向受力新技术对该窑机械参数做在线检测,按其给出调整方案实施窑调整后,该窑恢复正常生产。     

模具间隙对无取向硅钢冲片质量的影响研究

为了研究模具间隙对无取向硅钢冲片质量的影响规律,针对电机铁芯常用的冷轧无取向硅钢50WW470和50WW800,设计了一套高精度浮动式冲裁试验模具.通过系统性冲裁试验,分析模具间隙对冲片毛刺高度、回弹和椭圆度的影响.结果表明,冷轧无取向硅钢冲裁后,毛刺高度随模具间隙增加而增大;在一定范围内,回弹量随模具间隙增加而减小;椭圆度是由材料力学性能与残余应力分布不均匀综合导致的,板料垂直轧制方向的力学性能比平行轧制方向好,而平行轧制方向的残余压应力比垂直轧制方向大.因此,冲裁后零件平行于轧制方向回弹更大,故其尺寸也更大.去应力退火后,残余应力降低,各向异性程度降低,零件椭圆度降低10％～60％.     

Efficiency improvement of fluorescent blue device by molecular orientation of blue dopant

The relationship between molecular shape of fluorescent blue dopants (BDs) and degree of molecular orientation was studied. BDs with larger ovality showed higher degree of orientation and higher external quantum efficiency (EQE) over 10% in a fluorescent blue device. Impedance spectroscopy, transient electroluminescence spectroscopy, and optical simulation results highly indicated that such high EQE was originated mainly from the optical effect of horizontal‐aligned BDs. Furthermore, a higher EQE of 11.5% at a current density of 10 mA/cm² was successfully achieved by modifying molecular structure of BD.