基于S变换的汽车零部件疲劳载荷谱编辑法研究

小波变换和短时傅里叶变换为频域载荷谱编辑方法的主要分析工具,小波变换法分解函数及分解层数难确定和短时傅里叶变换法窗宽固定的缺陷,导致对随机载荷的分析结果存在偏差,影响载荷编辑质量.为解决此问题,基于S变换基本理论,探索S变换在载荷加速编辑领域的应用,对试验场采集的应变信号进行S变换分析提取最大幅值谱,并以此为依据提取轮...     

Analysis of S–N data for new and corroded mooring chains at varying mean load levels using a hierarchical linear model

Results from full scale fatigue tests of offshore mooring chains are analyzed. The data set includes new and used chains, tested at a variety of mean load levels. The used chains have been retrieved after operation offshore and include samples with varying surface conditions, ranging from as-new to heavily corroded. Based on a parameterized S–N curve intercept parameter, the effects of mean load and chain condition are estimated empirically by regression analysis. A hierarchical linear model is used, to account for and quantify correlations within subsets of the data. The choice of grouping criterion for the hierarchical model is discussed, and assessed based on the current data. Results show that the mean load and corrosion effects are both significant. Differences in the fatigue performance of new versus used chains are quantified and discussed.     

基于 B/S 架构的汽车工程数据云平台的设计与实现

汽车产品开发愈发需要海量且高质量的基础数据作为支撑，汽车工程数据体系非常庞杂且彼此间关联度强，因此，针对汽车工程数据库开发，需站在汽车产品开发者和项目管理者角度为其提供更柔性化、可视化、深度化的数据服务。开发了高压缩比的图形引擎，并设计了一种基于 B/S 架构的汽车工程数据管理平台，以轻量化的三维模型为载体实现工程数据的强关联，较大程度地解决了汽车工程数据管理分散易丢失、完整性和一致性差、不易检索和无法进行数据挖掘等痛点问题，为汽车工程数据管理和重用提供了一个新的思路。