一种兆瓦风电齿轮箱前机体结构轻量化设计

以经验为主导的传统齿轮箱箱体的设计方法已逐渐无法满足大兆瓦风电齿轮箱的设计要求。基于此,利用拓扑优化和尺寸优化方法,以轻量化设计为目的,在提高强度和保证刚度的条件下对风电齿轮箱前机体进行结构优化设计。前机体的有限元分析表明,有必要对其结构进行优化设计;基于多位置工况建立前机体的静动耦合拓扑优化模型,根据拓扑优化传力路径获得概念模型;采用响应曲面法对概念模型的关键尺寸进行优化设计,通过筛选法得到最优尺寸。对优化前后前机体的性能进行比较,质量减少12.79%,第一主应力基本不变,刚质比提高7.19%,实现了结构轻量化的目的

Corrosive Electrochemical Behavior of Carbon Steel in Microbiological Medium

硫酸盐还原菌 (SRB)生长代谢 ,溶液pH值从 7.5下降到 5.8,并在碳钢表面形成生物膜 ,改变了生物膜下碳钢表面的微环境 ,促进碳钢点蚀的形成 .清除表面的腐蚀产物后 ,碳钢基体表面为分布不均匀的溃斑 ,发生严重的点蚀行为 .而SRB的活性和生物膜的结构诱发碳钢腐蚀的形成和生长 ,在微生物快速生长过程中出现明显的氢扩散电流峰 ,加剧碳钢的渗氢行为 ,采用电化学阻抗 (EIS)研究了碳钢在微生物腐蚀过程中生物膜的结构与腐蚀相应的变化关系Sulfate_reducing bacteria(SRB)grows and propagates, PH of the solution is dropped from 7.5 to 5.8,and forms the biofilms on carbon steel in culture medium.The micro_environment on the surface of carbon steel is changed under the biofilms,the factors accelerate the formation of the pitting corrosion. When the biofilm on carbon steel is cleaned out,the surface of carbon steel have the non_uniform pitting corrosion. The activity of SRB and the porous structure of biofilms induced the initiation and development of the pitting corrosion of carbon steel.The process of microbiologically induced corrosion(MIC) involves the development of SRB activity,which promotes the permeation of gydrogen into the carbon steel.The relation of the structure of biofilms and corrosion was also studied using electrochemical impedance spectroscopy(EIS).作者联系地址：清华大学核能技术设计研究院,华中科技大学化学系,华中科技大学化学系,华中科技大学化学系,华中科技大学化学系,清华大学核能技术设计研究院 北京100084 ,湖北武汉30074 ,湖北武汉30074 ,湖北武汉30074 ,湖北武汉30074 ,北京100084Author's Address: 1.Institute of Nuclear Energy TechnologyINET,Tsinghua University,Beijing 100084,China; 2.Chem.Dept.,Huazhong University of Science and Technology,Wuhan 4300