基于载荷等效法的空气悬架客车有限元建模方法

根据客车车身及前后桥的静力学平衡条件建立了考虑纵向加速度时车身各支撑部件等效载荷的求解方法.详细讨论了空气弹簧、推力杆、稳定杆等效载荷及位移约束的施加方法,并利用有限元软件实现了某型空气悬架客车制动、起动及弯曲工况的有限元模拟.结果表明,建模方法能够反映客车车身的实际受力状况,为客车车身的结构优化提供了理论依据.     

汽车塑料燃油箱耐压性试验及有限元分析

为了研究汽车塑料燃油箱正常工作时的结构性能,建立燃油箱有限元分析模型,并利用Abaqus软件分析燃油箱内部受到不同极限压力时的应力及变形情况,试验结果验证了有限元模型的正确性.结果表明,燃油箱在内部承受极限正压力35 kPa时,其表面最大应力为8.977 MPa,最大变形为18.77 mm.     

钢筋混凝土简支梁承载力的有限元分析

通过有限元软件ANSYS对钢筋混凝土简支梁承载力的有限元分析过程进行模拟,着重讨论了有限元模型的选择,混凝土裂缝的处理,本构关系以及破坏准则.在进行混凝土结构非线性静力计算时,只有针对实际问题选择合适的本构模型,才能保证分析的准确性.为了能够得到较准确的极限载荷,在使用ANSYS进行钢筋混凝土简支梁的极限载荷分析时,采用了受压混凝土模型,并采用多线性等向强化模型MISO和双线性等向强化模型BISO进行模拟.模拟分析时建议关掉压碎选项,以易于收敛.     

Φ120mm柔性筛管球铰接头结构强度分析与优化

球铰连接柔性筛管的接头强度直接影响着柔性筛管的下入能力,运用ADAMS软件,在柔性筛管下入阻力估算的基础上,进行了Φ120 mm柔性筛管球铰接头强度研究以及关键参数分析。基于多体动力学理论,建立了阻力计算模型,通过理论分析与模拟计算相结合的方法,分析了井下柔性筛管阻力变化趋势,并使用ANSYS有限元软件研究了球铰接头在不同摆动角度时的受力变化,揭示了球铰接头的关键结构参数以及对接头强度的影响规律。结果表明：球形接头的结构强度能满足井下作业时的自重拉伸载荷；球铰的摆动角度对接头连接处受力变化明显,且危险截面位置不同,随着摆动角度增大会加重接头的承受负担；影响接头强度的关键影响因素包括接头边缘壁厚、边缘处的倾斜角度以及球头厚度,对其进行了优化处理,不仅能有效增强接头的力学性能,还提高了造斜段通过性。相关研究成果可为柔性筛管的优化设计提供参考。     

250t起重船打捞扒杆有限元强度分析

利用有限元分析软件建立了某内河250 t起重船打捞扒杆结构的有限元模型,通过直接计算方法对打捞扒杆在作业状态下的结构强度和稳定性进行了评估,以确定扒杆结构和性能的稳定性和安全性。首先进行了该非常规船舶的波浪载荷;其次,涉及起重船打捞扒杆作业状态下的载荷选取,然后评估了扒杆的强度和稳定性。该船打捞扒杆的强度评估方法与结果,可为今后此类内河小型起重船的臂架与船体结构设计提供参考依据。     

基于ISIGHT的商用车鼓式制动器的结构分析与优化

为了弄清鼓式制动器的结构,本研究以某款商用车型所使用的领从蹄式制动器为研究对象,对其建立了有限元仿真模型,同时通过模拟制动器的工作条件验证了制动蹄应力(符合使用要求);随后用Isight软件集成Catia和Abaqus,并选取制动蹄的三个结构参数作为设计变量,以制动蹄上的最大主应力作为优化目标,采用自适应模拟退火算法对制动器的结构参数进行了多目标优化,并通过有限元分析对优化结果进行了验证,优化结果表明,优化后的制动蹄最大主应力降低了10.89％,可有效地延长制动器的使用寿命.     

泡沫夹层结构复合材料机翼模型弯曲破坏形态有限元模拟

采用有限元法(FEM)分析泡沫夹层结构复合材料机翼准静态三点弯曲载荷力学行为与破坏形态.在有限元模型中,复合材料蒙皮为Hashin失效准则弹性壳单元模型,铺层结构为[0/90/0/±45]s,其芯层泡沫为弹塑性可压缩泡沫实体单元模型.利用有限元模拟软件ABAQUS10.1模拟机翼在弯曲载荷下的破坏形态,分析得到其破坏机理.通过最大受力值以及模型应力云图与实际弯曲试样破坏情况进行比较.结果表明,机翼最大承受力模拟值比试验值偏大,但相对误差很小,为3.31%;模型应力集中区域与试样实际断裂区域相吻合,证明了本有限元模型可以有效地用于预测泡沫夹层结构复合材料机翼在三点弯曲载荷作用下的失效模式以及失效强度.     

PHC桩的极限承载力试验与数值模拟研究

根据对PHC桩的静载荷试验,揭示PHC桩在竖向静载荷试验过程中沉降量变化规律,通过有限元分析软件ABAQUS建立有限元模型,阐述了模拟桩在静载试验中荷载沉降过程,对比沉降量值与试验值,通过有限元分析软件分析桩的极限承载力值.     

MW级复合材料风电叶片的振动特性与应力分布

针对目前风电叶片有限元模型存在铺层不合理的问题,以某1.5 MW风电叶片为研究对象,利用Solidworks软件生成叶片三维模型;再将其导入大型有限元软件Abaqus中,按照叶片铺层理论进行分区域铺层,生成叶片有限元模型,使其更接近叶片的真实铺层状况;在有限元数值计算中,分析了叶片的振动特性以及在50 m/s的极限风速下的应力分布特征.结果表明,叶片模型在模态、强度、刚度三个方面均满足设计要求,叶片的危险截面位于距叶尖约13处,应力主要分布于叶片展向的13~23处,且主要承载结构为主梁和腹板.     

轿车前悬架的有限元分析

为对桑塔纳 2 0 0 0型轿车前悬架进行静态有限元分析 ,在球铰等相互运动的零件之间添加一层特殊弹性材料 ,利用其弹性变形来模拟有限的相对运动。应用这种方法进行有限元建模 ,可以使前悬架的整体计算应力分布比较符合实际情况。计算了在一些典型工况下的应力分布 ,并就结构关键点 (高应力点 )的应力对各方向载荷的敏感性进行了分析。试验结果表明 ,应用该有限元模型得到的计算应力与试验结果吻合较好     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.