Elasto-plastic analysis of crack in metallic foams

To determine the solutions of the well-known problem of a finite width strip with single edge crack,some results on elasto-plastic fracture analysis for metallic foams are reported.Meanwhile,in order to discuss and put an insight into the nonlinear fracture analysis,the Dugdale model for plastic deformation of this configuration for metallic foams is recommended and solved.Combining the asymptotic solution with the Dugdale model and elastic solution,the stress field in the plastic zone and the size of the plastic zone are expressed as analytical forms.Based on Williams expansion method,the estimate of the scale factor is also completed and analyzed.In view of these analytical solutions,the results show the scale factor is a useful parameter for the fracture theory of metallic foams.     

工业燃气炉窑控制质量的改善

介绍了炉窑控制的当前状况、发展趋势和新的技术方法；详细论述了燃烧控制及交叉限幅工作原理，给出典型控制结构图和限幅器算法及适用范围，并分析其中参数对性能的影响；介绍了热值仪比值优化、热处理炉低温控制和孔板量程修正；讨论了温度设定数学模型，并结合实际描述一套棒材加热炉温度数学模型，其中包括时间待轧和自动待轧策略。     

高效离心式渣浆泵的工作原理和可行性研究

分析了在现有离心泵叶轮的基础上增设短叶片的新型高效离心泵的扬程，效率和使用寿命，叙述了基本结构和工作原理。     

移相控制软切换PWM开关电源设计

介绍一种移相控制软开关PWM开关式电源，简述了工作原理，讨论关键器件逆变变压器，谐振电感，谐振电容的参数设计问题，分布参数的影响下实现软开关的条件，说明了常规器件和逆变变压器的设计原则，及谐振器件参数的确定方法，并且给出了试验结果。