共查询到20条相似文献,搜索用时 93 毫秒
1.
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。 相似文献
2.
对降载勾线法作了适当的改进后用于含焊接缺陷构件的疲劳试验,获得了清晰的含焊接缺陷构件断口疲劳裂纹扩展图,在此基础上探讨了焊接缺陷对构件疲劳强度的影响规律。 相似文献
3.
对大型液压自动压砖机的预应力结构进行了分析,建立了机架预紧的力学模型,给出了预紧力的计算公式,分析了预应力对结构疲劳强度的影响。最后通过设计实例证明了预应力结构是可靠的。 相似文献
4.
采用超声波测试了模拟制备的典型热熔焊接缺陷,分析了缺陷的超声波特征,测试了缺陷对管道力学性能的影响。结果表明,超声波对面积型和孔洞型缺陷有良好的检测能力,并能准确测定缺陷的深度;超声波检测结果与力学性能检测结果具有良好的关联性,可以采用距离–波幅曲线灵敏度评判指标进行缺陷的质量分级评价。 相似文献
5.
6.
研究了烧结碳化硅在1200℃和1370℃高温条件下的动、静疲劳性能,结果发现由于烧结密度较低,材料的抗弯强度不高,但高温疲劳强度没有明显下降,并且动、静疲劳性能相近。断口观察和缺陷“冻结”分析表明在最大拉应力区附近的烧结缺陷的尖角处常是裂纹源,在此处萌生的裂纹沿烧结缺陷联结成为主裂纹并导致断裂。最后作者提出了陶瓷材料高温疲劳损伤的杂质空穴复合作用机制。 相似文献
7.
8.
对锅炉、热交换器管子-管板胀接结构的安全及可靠性进行了实验研究。研究范围包括胀接结构的连接强度,密封即耐压性能,疲劳强度等。作者提供了初步的研究结果及试验数据,为设计、制造及研究工作者进一步认识胀接结构的特性,修改现行规范中的有关规定提供了依据。 相似文献
9.
设备接管长期在循环载荷作用下,会产生疲劳开裂破坏。对于疲劳结构的设计,一般采用分析设计方法进行详细的应力分析来获得交变应力强度幅,进而进行疲劳强度评定。首先根据分析设计标准JB 4732—1995(2005年确认)确定了壳体的初始厚度,然后基于APDL语言建立了壳体与接管连接结构的三维全模型,并对其在设计工况与操作工况分别进行了应力强度分析与疲劳强度评定,结果发现结构满足应力强度要求,但不满足疲劳强度要求。通过调整接管的壁厚以及倒角尺寸,直到结构满足疲劳强度要求;同时也分析了接管内伸结构,该结构可以节省材料,提高疲劳寿命。 相似文献
10.
提出了根据模糊综合评判、定义结构参数用以表示焊接缺陷损伤程度的方法。建立了基于模糊集理论处理含焊接缺陷化工设备和管道承受疲劳载荷安全评定中解决不确定和非精确性的方法,并编制了相应的专家系统。 相似文献
11.
乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
13.
14.
D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
__________
Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
15.
16.
17.
Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
18.
A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
19.
塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献