石油化工圆筒炉的钢结构分析与优化

介绍如何在Staad.Pro中建立结构计算模型,并针对圆筒型加热炉钢结构提出模型简化的方法。对整个结构进行分析计算,根据计算结果提出结构优化方案。按照SH/T 3070-2005《石油化工管式炉钢结构设计规范》进行检验,比较与普通GB 50017-2003《钢结构设计规范》的异同。所介绍的设计方法可为Sta-ad.Pro有限元分析软件在其他类似工程设计中的应用提供有益的参考。     

荷载取值费思量——《荷载规范》学习心得

对《建筑结构荷载规范》的一些条文，从规范确定楼面均布活荷载的原则出发，提出一些看法和建议。     

天然地基承载力设计值的探讨

指出了在《地基基础设计规范（DGJ08-11-1999上海地区）》中,采用土的抗剪强度指标确定地基承载力设计值的局限性,并从理论上较深入地分析了其原因,同时通过实际的工程实例提出了将原位测试方法确定地基承载力设计值充实到该规范中的必要性。     

欧洲规范8与中国抗震设计规范关于抗震设防目标和地震作用的比较

在抗震设防目标、反应谱、地震作用和实现抗震设防目标的方法等方面对欧洲规范8（Eurocode8）2003版和中国《建筑抗震设计规范》2001版进行了比较，分析了欧洲规范中引入性能系数q的原因及其带来的影响。     

Failure behavior of horseshoe-shaped tunnel in hard rock under high stress: Phenomenon and mechanisms

A particle flow code (PFC) was first applied to examining the mechanical response of a horseshoe-shaped opening in prismatic rock models under biaxial compression. Next, an improved complex variable method was proposed to derive the stress distribution around the opening. Lastly, a case study of tunnel failure caused by rock burst in Jinping II Hydropower Station was further analyzed and discussed. The results manifest that a total of four types of cracks occur around the opening under low lateral confining stress, namely, the primary-tensile cracks on the roof-floor, sidewall cracks on the sidewalls, secondary-tensile cracks on the corners and shear cracks along the diagonals. As the confining stress increases, the tensile cracks gradually disappear whilst the spalling failure becomes severe. Overall, the failure phenomenon of the modelled tunnel agrees well with that of the practical headrace tunnel, and the crack initiation mechanisms can be clearly clarified by the analytical stress distribution.     

基于PLC的具有分拣功能的自动化立体仓库设计

随着我国经济的高速发展,铁路、公路货物集散中心陆续出现,货物流通趋于小批量、多品种和准时制,各类配送存储中心的货物分拣任务十分艰巨。我国目前多数配送存储中心都是人工分拣,这种方式无法满足大规模存取配货的要求。而以往的自动化仓库中仅仅针对于一种货物的储存和管理,为此该文提出了一种具有自动分拣能力的自动化立体仓库的设计。系统中使用条码扫描装置来识别货物,整个操作过程可以通过触摸屏来控制,大大提高了系统的自动化水平。     

光滑极限量规数字化管理系统的设计与实现

光滑极限量规是机械生产过程中重要的检验工具。分析了光滑极限量规管理的现状。针对光滑极限量规管理过程中由于身份标识不清导致的管理混乱、检定成本增加等问题,利用ASP.net技术,并结合编码技术、条形码技术,建立了一种光滑极限量规数字化管理系统,有效解决了上述问题。系统在实际使用中效果良好。     

A numerical modelling approach to assess the behaviour of underground cavern subjected to blast loads

The paper gives an insight into the behaviour of large underground caverns which are subjected to blast loads. Caverns are generally constructed in hard rock formation which compels us to use blasting methods for the excavation works. Comparative study was done between models with intact rock mass and discontinuities to assess the stability of cavern as a result of blast loads. Numerical modelling was performed with 3 dimensional distinct element code(3 DEC) to analyse the performance of cavern walls in terms of displacement and to compute peak particle velocities(PPV) both around the cavern periphery and at surface of models. Results showed that the velocity wave with higher frequency exhibited large displacements around the periphery of cavern. Computation of PPV showed that model with horizontal joint sets showed lower PPV in comparison to model with intact rock mass. PPV values were also analysed on the surface for model consisting vertical joints spaced at 4 m intervals. Comparative study of PPV on surface vertically above the blast location between models with horizontal joints spaced at 4 m and vertical joints at 4 m intervals were conducted. Results depicted higher magnitudes of PPV for model with vertical joints in comparison to model with horizontal joints.     

自动车床凸轮CAD设计

自动车床因其加工零件的过程自动化,生产效率高,被广泛应用于仪器如仪表工业中的细长多阶梯轴类零件的批量生产,是一种机械加工中不可缺少的设备;但自动车床加工零件所用的工装凸轮设计计算繁琐,容易出错。本文通过计算机辅助设计软件CAD,设计了一套应用程序,成功解决了这一问题,其具有可借鉴性强、组织流畅、适用范围广、准确性高、操作方便和运行速度快的优点。软件的计算卡和凸轮图样全部输出在底图样上,节省了大量的人力、物力,提高了经济效益。