内压简体开孔接管结构应力集中系数预测

针对内压筒体平齐式大开孔率开孔接管结构，提出一种基于有限元解的有效的应力集中系数（SCF）估算的经验公式。认为应力集中系数是A=d／√DT，n=T／D和ζ=（Dt）/（dT）函数，对近100个不同尺寸规格开孔接管结构的应力集中系数进行了较详细三维有限元分析计算，采用最小二乘法对应力集中系数规律进行了回归分析，得到了应力集中系数计算的经验公式，另外用83个开孔接管结构的有限元解与其进行了对比计算。结果表明，此经验公式的计算精度可以满足一般工程问题的要求。     

内压筒体开孔接管结构应力集中系数预测

针对内压筒体平齐式大开孔率开孔接管结构,提出一种基于有限元解的应力集中系数(SCF)估算的经验公式,认为应力集中系数是λ=d/DT、η=T/D和ζ=D t/(dT)函数。对近120个不同尺寸规格开孔接管结构的应力集中系数进行了较详细的三维有限元分析计算,采用最小二乘法对应力集中系数规律进行了回归分析,得到了应力集中系数计算的经验公式,另外用83个开孔接管结构的有限元解与其进行了对比计算。结果表明,此经验公式的计算精度可以满足一般工程问题的要求。     

内压筒体开孔接管结构应力集中系数预测

针对内压筒体平齐式大开孔率开孔接管结构,提出一种基于有限元解的有效的应力集中系数(SCF)估算的经验公式。认为应力集中系数是λ=d/DT~(1/2),η=T/D和ζ=(Dt)/(dT)函数,对近100个不同尺寸规格开孔接管结构的应力集中系数进行了较详细三维有限元分析计算,采用最小二乘法对应力集中系数规律进行了回归分析,得到了应力集中系数计算的经验公式,另外用83个开孔接管结构的有限元解与其进行了对比计算。结果表明,此经验公式的计算精度可以满足一般工程问题的要求。     

筒壁开小孔的厚壁圆筒形构件的疲劳强度及合理开孔结构

对筒壁开小圆孔的厚壁圆筒疲劳强度进行了试验研究，得出了不同开孔结构（垂直开孔、斜开孔和切向开孔）的开孔疲劳强度影响系数；分析计算了厚壁圆筒开小孔时的应力集中系数；分析比较了开孔应力集中系数与开孔疲劳强度影响系数间的关系；提出了厚壁圆筒形构件筒壁开孔的合理结构形式。     

开孔间距对压力容器应力影响的有限元分析

采用ANSYS Workbench软件进行开孔间距对压力容器应力影响的有限元分析。结果表明:应力集中程度受开孔间距的影响,随着K值增大,应力集中系数减小,当K1.3时,应力集中系数基本不变。开孔接管区的最小应力反应了两孔间干涉作用的强弱,随着K值增大,开孔接管区的最小应力逐渐减小,说明两孔间的干涉作用逐渐减弱。     

高流速大开孔压力管道三通的应力分析

压力管道三通是压力管道中最典型的结构,针对在运输过程中,大开孔接管结构位置易遭破坏而损坏管道完整性的问题,对大开孔接管结构的相贯区域产生的应力集中部分进行分析。在理论分析建模的基础上,运用有限元ANSYS仿真软件对压力管道大开孔率接管相贯部位局部应力集中的规律进行分析,确定压力管道接管位置的应力随开孔率大小的分布规律,为设计与制造压力管道开孔接管提供理论依据。     

封头开孔接管应力集中计算精度的研究

对球形封头上不同开孔率的接管在内压作用下的应力分布进行了有限元分析计算，对接管根部表面及内部各点的弹性应力采用各种不同精度的有限元网格得出的计算值进行了对比分析，并且对接管根部各载面进行了应力线性化处理，得出了不同精度的网格和接管极部不同的过渡形式下的薄膜应力分成，弯曲应力成分和峰值应力成分，分析研究了接管根部不同的过渡形式对薄膜应力集中，薄膜加弯曲应力集中和表面应力集中的影响及不同精度的网络对这些应力集中计算精度的影响。     

封头开孔接管应力集中计算精度的研究

对球形开头上不同开孔率的接管在内压作用下的应力分布进行了有限元分析计算。对接管根部表面及内部各点的弹性应力采用各种不同精度的有限元网格得出的计算值进行了对比分析，并且对接管根部各截面进行了应力线性化处理，得出了不同精度的网格和接管根部不同的过渡形式下的薄膜应力成分、弯曲应力成分和峰值应力成分，分析研究了接管根部不同的过渡形式对薄膜应力集中、薄膜加弯曲应力集中和表面应力集中的影响及不同精度的网格对这些应力集中计算精度的影响。     

夹套式容器大开孔的补强方法

大开孔压力容器在开孔接管部位有很大的应力集中,必须进行补强。利用有限元单元法和压力面积法对夹套式容器大开孔进行分析。通过数值计算表明:采用有限元分析软件能够很好的解决设备大开孔问题,为合理设计和结构在使用条件下能否安全使用提供了重要参考依据。     

内压圆筒斜接管的强度研究与应力评定

以内压圆筒斜接管为研究对象,借助ANSYS有限元分析软件,通过改变筒体内径、接管内径、筒体厚度、接管厚度、接管与筒体夹角5个参数,考察其对圆筒轴向斜接管开孔接管区最大等效应力的影响,并对其进行应力安全评定。结果表明,随着接管内径、筒体内径的增大,最大等效应力呈增大的趋势;随着接管厚度、筒体轴线与斜接管轴线的夹角、筒体厚度的增大,最大等效应力呈减小的趋势;通过应力集中系数的计算,可以控制接管内径和夹角θ=75°～90°减小应力集中系数。所得结论对压力容器设计提供借鉴作用。     

底座连接口特征参数对显示器后壳注塑质量的影响分析

在Moldflow分析软件的基础上,对显示器后壳进行仿真研究,以翘曲变形量为质量指标,结合控制变量法进行单因素变动实验,保持注射工艺参数不变,研究显示器后壳底座连接口对制品翘曲变形的影响.对数据进行图表分析,结果表明显示器后壳尺寸定位68.58 cm(27英寸)时,底座连接口选用圆形,连接口位置距离底边26 mm,尺寸...     

The role of the symmetry and the flexibility of the anion on the characteristics of the nanostructures and the viscosities of ionic liquids☆

The transport properties of ionic liquids (ILs) are crucial properties in view of their applications in electrochem-ical devices. One of the most important advantages of ILs is that their chemical–physical properties and conse-quently their bulk performances can be well tuned by optimizing the chemical structures of their ions. This will require elucidating the structural features of the ions that fundamentally determine the characteristics of the nanostructures and the viscosities of ILs. Here we showed for the first time that the“rigidity”, the order, and the compactness of the three-dimensional ionic networks generated by the anions and the cation head groups determine the formation and the sizes of the nanostructures in the apolar domains of ILs. We also found that the properties of ionic networks are governed by the conformational flexibility and the symmetry of the anion and/or the cation head group. The thermal stability of the nanostructures of ILs was shown to be con-trolled by the sensitivity of the conformational equilibrium of the anion to the change of temperature. We showed that the viscosity of ILs is strongly related to the symmetry and the flexibility of the constitute ions rather than to the size of the nanostructures of ILs. Therefore, the characteristics of the nanostructures and the viscosities of ILs, especially the thermal stability of the nanostructures, can be fine-tuned by tailoring the symmetry and the conformational flexibility of the anion.     

浅谈设备的性能与操作对胎面压出质量的影响

简要介绍了胎面压出的工作原理及工艺过程，对设备的配置及操作对胎面压出质量的影响进行了分析，并对压出过程中常见的质量缺陷、造成的原因以及解决措施提出了自己的见解。     

Investigation of the effects of fatty acids on the compressive strength of the concrete and the grindability of the cement

In cement industry, a great energy consumption has been observed during grinding of clinker. To reduce this consumption, some waste products have been used as grinding aids.In this investigation, the effects of sunflower oil (SO), oleic acid (OA), stearic acid (SA), myristic acid (MA) and lauric acid (LA) on the fineness and strength of the cement have been examined. These aids were added into clinker in certain ratios based on the cement clinker weight and the grinding has been done for a definite time at the same condition.All of the fatty acids used increased the fineness as compared with the cement without the grinding additives. SO and OA decreased the strength significantly, LA decreased it to a lesser extent and SA increased it definitely according to the common cement. But MA did not alter the strength of the cement as much as SA. In addition, the covering of the balls influences the grinding of cement clinker unfavourably.     

煤粉流动性对GSP气化炉气力输送的影响研究

针对GSP气化装置煤粉气力输送在试车阶段出现的煤粉锁斗下料不畅、发料罐输送性能不佳等问题,从原料煤性质和工业装置的改进方面出发,通过煤粉的流动性参数的测量与研究,分析出现上述工程问题可能的内在原因,并提出工业装置改进方法,为保证GSP煤粉气力输送工业装置的正常运行提供解决办法。     

关于建立火炸药安全数据库的探讨

由反映火炸药及其制品的危险性能和用于对它们的生产、储运系统进行安全评价数学模型出发,探讨了如何建立一个全面、实用的火炸药安全评估数据库。通过对此数据库内容、数据表示方法、数据搜索方法以及建立步骤的讨论,明确了该数据库的使用对象和主要功能。     

The effect of the length of the oxyethylene chain on the conductivity of the polyurethaneurea electrolyte

Polyurethaneureas (PUU), which were synthesized from 4,4′-diphenylmethane diisocyanate (MDI), poly(ethylene glycol) (PEG), and 3,5-diaminobanzoic acid (DABA), were used as polyelectrolytes in this study. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) were used to monitor the effect of the various kinds of PEG on the changes in morphology of PUU electrolytes corresponding to the concentration of lithium perchlorate (LiClO₄) dopants. The results of DSC and FT-IR indicate the Li⁺ ions coordinate with the soft and hard segments. Additionally, the crystallinity of the PEG soft segment and the ordered hydrogen-bonded urea carbonyl groups decreased with increasing salt concentration. Impedance spectroscopy (IS) measurements show that the PUU electrolyte with the high phase separation degree has the high ionic conductivity. The hard-segment T_g and the soft-segment T_m influence the conductivity behavior of polyelectrolytes with increasing measurement temperature.     

转子挤压组合凹模的应力分析

组合凹模的应力分析是一个非常复杂的问题，对其进行精确分析是解决模具寿命的关键。本文采用有限元分析软件Ansys对转子的组合凹模进行了分析，为转子组合凹模的优化设计提供了依据。     

Effect of the drafting force on the strength of the bottom of the spinneret

In spinning basalt fibres, the drafting force is in the same range as in spinning of glass fibres. The effect of the drafting force can not be considered in the calculation for the strength and rigidity of the bottom of the spinneret. __________ Translated from Khimicheskie Volokna, No. 5, pp. 47–50, September–October, 2007.