ANSYS三维模型中SOLID65单元的内力提取问题

ANSYS有限元程序中的SOLID65单元是一种适合描述钢筋混凝土结构的三维单元。由于加强材料在本构矩阵中的组结方式,使用该单元建立的钢筋混凝土模型在进行常规内力提取时会发生错误。在分析单元本构矩阵组结的基础上,正确的内力提取方式被提出。通过例题验证了该提取方法的正确性,并和常规方式进行了对比。     

预应力混凝土梁开裂后的受力性能分析

基于实体退化壳单元,采用层状模型模拟钢筋混凝土结构,选取恰当的混凝土和钢筋的本构关系,采用弥散裂缝模式,考虑材料非线性效应有效地模拟了预应力混凝土T梁的开裂、屈服和失效全过程,并与试验结果进行比较。分析了T梁在开裂后的刚度及裂缝的位置和发展情况。探讨了混凝土和预应力钢筋在T梁开裂后的应力发展规律。结果表明退化分层壳单元模型对于预应力混凝土T梁的非线性分析有良好的适应性。     

Geochemical controls on distributions and speciation of As and Hg in sediments along the Gaoping (Kaoping) Estuary–Canyon system off southwestern Taiwan

Surface and box-cored sediments were collected along the Gaoping (formerly spelled Kaoping) Estuary–Canyon system and analyzed for As and Hg contents and speciation, ²¹⁰Pb-based sedimentation rates and various geochemical parameters to elucidate the mechanisms that control natural and anthropogenic inputs of As and Hg from the Gaoping (Kaoping) River (KPR). The contents of As and Hg in surface sediments ranged from 1.84 to 20.7 mg kg^− 1 and from 0.07 to 2.15 mg kg^− 1, respectively, in the estuary and canyon. The concentrations generally decreased from the lower river toward the mixing boundary and then increased toward the estuarine mouth, followed by a slight variation in the canyon. Both As and Hg concentrations correlated strongly with clay, total organic carbon (TOC), Al, Fe and Mn contents in estuarine sediments but not necessary the same cases for canyon surface sediments. The factor analysis of surface sediments shows that the first two factors, which account for 75.6% of the variance, may represent major roles of carriers (clay, Al and Fe–Mn oxides) and TOC in controlling As and Hg distributions, respectively. Accordingly, the spatial patterns of the enrichments of As (1.9–16.2) and Hg (1.8–30.8) with reference to the crust levels follow the individual element's distribution patterns, likely because of deposition variability following inputs from the river. The contents of mobile As and Hg correlated substantially with the contents of both metals that were extracted with 0.1 M HCl. In addition to the major pool in the residual fraction (65–87%), As was relatively abundant in Fe–Mn oxides/hydroxides, whereas Hg was abundant in the organic/sulfide fraction. The deposition and accumulation rates of As and Hg in the canyon clearly decreased as the depth of water increased. The depth distributions of both metals are likely controlled primarily by TOC and Fe–Mn oxides associated factors followed by a contribution from anthropogenic pollution. The metal pollution appears to have increased substantially around 1970, following the economic boom in Taiwan, suggesting that modern sediments in the Gaoping (Kaoping) Canyon were derived from the Gaoping (Kaoping) River (KPR).     

论我国履行《国际海运固体散装货物规则》的策略

《国际海运固体散装货物规则》（《IMSBC规则》）即将于2011年1月1日生效。文中结合近年来发生在渤海海域的多起载运固体散装货物的船舶沉没事故教训,探讨了我国目前在固体散装货物海运相关作业和安全监管方面存在的问题,论述我国履行《IMSBC规则》的必要性,并分别从装货前检测、货物安全适运性申报、港口管理、船舶管理、现场监管等方面提出我国通过国内立法建立履行《IMSBC规则》机制的策略。     

工程机械柴油机后处理技术的缺陷分析及改进方向

为适应绿色施工的要求,工程机械柴油机排气净化越来越重视采用固体颗粒捕集和排气催化转化等后处理技术。本文对常用后处理技术的应用效果进行了定性评价,分析了技术局限性,提出了改进后处理技术的主要方向。     

固态胺纤维吸附CO2速率实验研究

模拟核潜艇环境工况条件,对固态胺纤维吸附CO2进行研究。实验测定了环境温度25℃、环境压力101kPa、气相中CO2含量0.5%时,固态胺纤维有水存在下吸附CO2的速率为5.57×10-4mmolig-1is-1。理论分析了吸附速率的控制过程,结果表明固态胺纤维吸附CO2总速率受双膜理论的液膜控制。     

潜艇舱室固态胺CO2清除技术的动力学分析

分析了潜艇舱室固态胺CO_2吸附及水蒸汽再生的反应机理,指出了CO_2水合反应和水合CO_2分解反应分别为吸附与再生过程的慢反应。在实际工况下,固态胺吸附CO_2的速率受传质控制,水蒸汽再生过程很快,其速率不是主要关注的问题。基于双膜理论及双电层理论,分析讨论了固态胺吸附传质过程,推导出了CO_2总的传质速率方程,给出了影响速率的两个可调因素--温度及固态胺的含水量。     

采用砼四脚锥体加固黄河坝岸根石的建议

砼四脚锥体属四面体的变形体,具有重心低、稳定性强、裹护效果明显等特点,在险工坝岸根石加固中代替传统的散抛块石固根,经德州黄河南坦险工实践证明:砼四脚锥体固根能有效减少险工坝岸根石走失,稳定险工基础,减少工程出险几率,提高抗洪能力。     

基于Solid Edge装配环境下管道设计的研究与实现

在分析企业管道设计需求及Solid Edge软件的基础上，结合管道自身的特点，利用中心线进行管道的干涉判断与调整，提出了二次投影干涉检验算法。该算法基于发生干涉的物体共用相同的空间，其投影图形也必定相交的事实，将三维图形转变成二维图形进行干涉判断，大大地降低了计算难度。     

巴哈赛车的悬架优化设计及操稳性分析

文章利用悬架的基本草图（前、后、侧视图）,在草图中对平面硬点进行约束,布置出悬架的基本平面结构并确定各个结构的参数值以及位置。绘制悬架需要的零件并且在CATIA中进行装配,形成3D效果图。通过Solidworks将前后悬架模型参数化处理,检查在CATIA中组装的模型是否干涉,确定各个连接点是否有间隙并从中获取悬架的硬点空间坐标实现数据迁移。通过Solidworks得到的硬点坐标在Adams-car中建立模型,绘制部件形体输入悬架相关参数根据不同的运动方式添加运动副以及通讯器。将建立的虚拟样机进行仿真从后台调出仿真数据分析查看在模拟工况中悬架参数是否在一个合理的范围内波动。最后将不合理的数据在Adams-insight中进行进一步优化,重新导出一套符合设计目标的硬点坐标。