Topology optimization for crashworthiness of thin-walled structures under axial crash considering nonlinear plastic buckling and locations of plastic hinges

Although topology optimization is established for linear static problems, more effort is required for solving nonlinear plastic problems. A new topology optimization approach with equivalent static loads (ESLs) is suggested to find the optimum topologies and locations of plastic hinges of thin-walled crash boxes by considering crash-induced deformation, the main crash energy-absorbing mechanism. Together with finite element method crashworthiness analyses, considering all nonlinearities with rate-dependent plasticity, the method was developed using an appropriate time-incremental scheme of ESLs without removing any high values of loads. Analyses show that the crash boxes with optimum topologies have energy-absorbing capabilities equivalent to the original structure. The proposed method is evaluated for two crashes: a crash box at low speed and a double cell subjected to high-speed collision. The results indicate that this method captures nonlinear crushing behaviours and accurate locations of plastic hinges where, if proper reinforcements are made, energy absorption can be enhanced.     

黑匣子高温测试仪的开发

采用物质的相变吸热原理，可以将高温环境传人保温箱的热量重新排回至高温环境，有效地提高了保温箱的抗高温能力，并对保温箱的隔热性能做了简单的理论推算和测温反向试验。温度测试仪选用超低功耗CPU，具有体积小、耗电少的优点，使黑匣子高温测试仪在运行过程中具有很好的安全可靠性。     

车载电子设备机柜布线工艺设计

对电子机柜传统的走线方式进行了分析、解剖，提出了新的走线方案模式，从工艺角度对机柜走线结构进行了改进设计，使之更适合于车载机柜的布线要求。     

微波陶瓷基印制板制造工艺性研究

对微波陶瓷基印制板的制造工艺流程进行了简单的介绍,对所采用的工艺技术的有效性进行了较为详细的论述。     

The influence of the fabrication process on the buckling of thin-walled steel box sections

Steel box sections are usually fabricated from flat plates which are welded at the corners. The welding process can introduce residual stresses and geometric imperfections into the sections which can influence their strength. For some thin-walled sections, large periodic geometric imperfections have been observed in manufactured sections. Subsequent investigations have indicated that the imperfections are in fact buckling deformations i.e. the box section has buckled due to welding residual stresses prior to any application of external load. The welding procedure and the behaviour of the box sections under load has been modelled using a finite element analysis that accounts for both geometric and material non-linearities. Tests have been carried out on box sections with a range of width to thickness ratios for the plate elements. Modelling has been shown to give good correlation with the test results. The conditions for buckling to take place as a result of the welding process have been established. A design method has been proposed.     

浅谈门式刚架轻型钢结构厂房中抗风柱的设置

通过对抗风柱上下端的节点几种形式进行分析比较,提出建议性的节点连续方式。     

Issues in nonlinear stochastic grey box identification

Grey box identification refers to the practice of identifying dynamical systems in model structures exploiting partial prior information. This contribution reviews a method for stochastic grey box identification and surveys experiences and lessons of applying it to a number of industrial processes. Issues to be addressed include advantages and costs of introducing stochastics into the model, the question of what contribution must be expected from the model designer as opposed to what can be formalized in computer algorithms, and an outlook on future plans to resolve present shortcomings.     

新产品——钢带增强聚乙烯螺旋波纹管

钢带增强聚乙烯螺旋波纹管是一种创新的埋地排水管,把钢材的高刚度、高强度和聚乙烯的柔韧、耐腐结合在一起,突出的优点是环刚度高和节约原材料.     

具多件内装物的瓦楞纸箱尺寸优化设计

跳出传统的设计思路，提出装多件内装物的瓦楞纸箱尺寸优化设计方法，建立优化设计模型，编写程序用于生产，节省纸用量，降低成本。     

可膨胀波纹管技术在韦15-19井的应用

可膨胀管包括可膨胀实体管和可膨胀波纹管，主要用于在不减小井眼尺寸的情况下封堵各种复杂地层，对损坏套管进行补贴修复，作为各种井筒封隔器以及延长技术套管长度。实体管和波纹管两者膨胀机理不一样，相比之下，可膨胀波纹管技术具有膨胀工艺简单，作业周期短的优点，该技术一直由俄罗斯掌握。中国石化勘探开发研究院经过多年的潜心研究，终于形成了具有自主知识产权的可膨胀波纹管产品及其配套的工艺技术，新研制的可膨胀波纹管壁厚8mm，抗内压强度35MPa，抗外挤强度10MPa，并在江苏油田韦15—19井进行了漏层封堵现场试验，经过扩眼、管串下入、水力膨胀、机械膨胀等工艺后获得圆满成功，标志着我国已经打破了国外公司对该技术的垄断，填补了国内在该领域的技术空白。