基于响应曲面法的闸板防喷器壳体优化设计

针对FZ35-105防喷器存在体积大、质量大等难题,建立105 MPa闸板防喷器壳体承载数值计算模型,研究防喷器壳体长度、宽度和高度对力学性能的影响。基于响应曲面法设计了17个实验组,系统研究了壳体长度、宽度和高度之间交互作用对壳体应力影响,构建了以等效应力为响应值的二次响应面模型,通过求解得到最小响应值下闸板防喷器最优壳体尺寸参数,并将优化前后结构强度进行对比。采用有限元与响应曲面相结合方法,为防喷器壳体尺寸优化提供了新思路,也可用于其他多参数优化设计。

Residual Stresses and Forming Quality of Metal Bipolar Plates for PEMFC During the Stamping Process

Stamping is a critical step in the manufacture of metallic bipolar plates.Typically,residual stress and a spring back effect appear on the bipolar plate after the stamping process,which impacts on the performance and lifetime of the proton exchange membrane fuel cell(PEMFC).The residual stress and spring back behavior which occur as a result of stamping a bipolar plate are investigated in this study.The effects of the punch radius,the die radius,the channel depth,and the clearance between the punch and the die on the residual stress and forming quality of the bipolar plate are examined.The stamping process can be divided into three stages.The high stress area and the middle section residual stress area were selected to study the formation process and to obtain the composition of the residual stress regions.Spring back was mainly related to the position of the fixed end of the sheet and the degree of plastic deformation,and the sheet thickness have increased by 2μm after spring back.Based on the results of finite element analysis,as described by the distribution of residual stress,the formation,the thickness of the middle cross section and the equivalent plastic strain,it was found that all the tool parameters affected the distribution of the residual stress.This research can provide a design reference for the manufacture of metallic bipolar plates based on the stamping process.

封井后提放钻杆过程中球形防喷器胶芯力学行为

球形防喷器封井后强行起下钻作业极易导致胶芯密封失效,为研究动密封过程中防喷器胶芯失效机制,基于橡胶大变形理论建立球形防喷器动态密封数值模型,探究球形防喷器胶芯在封井和起下钻过程的应力分布和失效模式。结果表明:球形防喷器密封钻杆后,胶芯内壁会产生条状褶皱,支撑筋下板块拐角处产生鼓点状应力分布,颈部和背部存在应力集中现象;当钻杆倾斜时,钻杆与胶芯接触密封区也发生倾斜,胶芯左右两侧应力小幅增大;起下钻过程中,胶芯内壁的条状应力集中变为片状分布,钻杆接头进出密封区域时,接触应力发生突变。