AN ADAPTIVE ITERATION METHOD FOR STRUCTURAL STATIC REANALYSIS of TOPOLOGICAL MODIFICATIONS

基于guyAn缩减和EPSIlOn算法,提出了结构拓扑修改静态重分析的自适应迭代方法。首先将新增加的自由度通过guyAn缩减方法凝聚到原结构自由度上,形成缩减方程。其次,根据刚度矩阵增量,利用nEuMAnn级数建立基向量,采用向量EPSIlOn算法对基向量部分和系列进行迭代加速,并给出了控制迭代收敛精度的误差计算方法,可以根据结构改变的大小自适应选择迭代次数,从而快速求出原结构自由度的位移。新增加自由度的位移可从缩减方程恢复得到。给出了一个数值算例,将该方法与组合近似法(CA)进行比较。数值计算结果表明,该方法可以根据精度要求自动选择迭代次数,且计算效率比CA方法高。Based on the Guyan reduction and epsilon algorithm, an adaptive iteration method for structural static reanalysis of topological modification is presented.In this process, the equations of the newly added degree of freedoms(DofS)(if any) are condensed to the original structure by means of Guyan reduction.And then, the basis vector is formed using Neumann serial according to the increment of the stiffness matrix, and the epsilon algorithm is used to accelerate the convergence of the partial sum of the basis vectors.An error evaluation method is introduced to control the accuracy of the iteration adaptively.A numerical example is given to compare the computational cost and approximation accuracy between the combined approximation and the presented method, the numerical results show that the present method is effective and easy to integrate into a general optimization approach.国家自然科学基金项目(50905033);中国博士后科学基金项目(20070420761);广东省自然科学基金项目(8451009001001414);广州市科技计划项目(2006Z2-D9061);广东省科技计划项目(2009B010900032);粤港招标项目(20070103-1

岩体微平面损伤模型的Abaqus用户子程序Vumat验证

本文探讨岩体微平面损伤模型~([1])在Abaqus中的实现。对课题组编制的Vumat用户子程序,采用砂岩三轴压缩试验进行算例验证。算例分析表明,该模型能表征砂岩的脆延转换宏观力学行为对应的各向异性损伤力学机制

Research on the automatic tool changer system of the machining center

自动换刀系统(ATC)包括刀库机构、换刀机构以及控制系统3个部分,是加工中心的重要组件之一。为了解决数控加工中心自动换刀速度慢、稳定性低及控制系统编程复杂等问题,将一种软件式内置PlC技术应用于自动换刀系统中。在分析自动换刀系统的基本结构、工作原理以及研究圆盘刀臂式自动换刀系统的控制流程的基础上,结合SErVOWOrkS CnC技术,开发了适用于各种自动换刀机构的PlC程序以及宏程序。最后,将所开发的控制系统应用于yy-1060立式加工中心,其在4 S~6 S内可完成整个换刀过程。研究结果表明,换刀过程快捷、准确、可靠,完全能够满足使用的要求。The automatic tool changer(ATC),which includes a magazine,a tool changer and a control system,is one of the key components of the machining center(MC).General issues of the ATC,however,are its slowness and low stability during tool changes and the complexity of control system programming.To solve those problems,one type of software and its internal PLC technology were investigated.Based on an analysis of the fundamental structure and operating principle of the ATC system and a research of the control procedure of the "disc with arm"-type ATC,the PLC program and macro programs combined with ServoWorks CNC technology were developed.Finally,it was shown that the newly designed control system can complete the whole process of changing tools in 4 to 6 seconds on the YY-1060 vertical MC.The results indicate that the process is rapid,accurate and reliable enough to completely meet the practical requirements

Application of EtherCAT fieldbus in servo motion control system

为实现ETHErCAT现场总线在伺服运动控制系统中的具体应用,以五轴运动控制系统的研发为背景做了研究与测试。系统主站控制器采用爱迪纳控制技术(厦门)有限公司的AdX CnC纯软件开放式数控系统,从站设备由ETHErCAT从站接口控制器ET1100和dSP芯片组成,并由此构建了一主一从的ETHErCAT网络结构。研究结果表明:该技术可实现系统的实时信号传输和精确位置控制。To achieve the application of EtherCAT fieldbus in servo motion control system,some research and tests were done based on the five-axis motion control system.ADX CNC system was used as the master controller,which is a pure software open CNC system designed by Amoy Dynamics(Xiamen)Co.,Ltd..The slave station was consisted by EtherCAT slave controller ET1100 and digital signal processing(DSP).Research results show that the real-time transmission of signal and accurate position control can be achieved using the one-master and one-slave EtherCAT network structure

足球踝发生的三维光弹性力学研究

目的:阐明足球踝的发生机制,探寻易发生足球踝的踢球姿势和力度,并为临床治疗提供指导。方法:解剖成年男子右侧带足小腿,量化分析其生物力学性质,制作环氧树脂距骨模型及应力冻结,切片后光弹仪观测,分析结果。结果:①踝关节跖屈35°位时,距骨表面所受拉应力远大于跖屈45°位时。②以相同姿势踢近或踢远,踢近时距骨表面所受拉应力较大。③拉应力集中区域为内踝后部、后踝中部及内侧,以及距骨滑车关节面前部等部位。结论:①以跖屈35°位的姿势踢球会增加足球踝的发生率。②高频率、小力度、踢近的踢球方式,会增加足球踝的发生率。③踢球对踝关节所造成的损伤主要集中在内踝后部、后踝中部及内侧,以及距骨滑车关节面的前部等

“足球踝”发病机制研究进展

运动员踝关节骨关节病在运动员中非常多见,1943年Morris 1943年称其为"运动员之踝",McMurray在1950年提出本病应叫"足球踝"。1957年O,Dongoghue提出将本病称为"踝关节撞击性骨疣"(impingement exotosos)

控制肝脏组织发育、再生重塑与大小的关键蛋白质机器

肝脏损伤、功能衰竭及肝癌等疾病是我国重大健康问题,它们的发生发展与肝脏再生重塑及大小调控异常密切相关。针对肝脏发育、再生及大小控制机理的基础研究对于解决上述重大肝脏疾病的临床需求具有重要意义。前期研究发现Hippo信号通路在调控细胞增殖及分化、干细胞命运等方面起着关键作用,而Hippo通路的失调可导致肝脏等器官发育和大小异常,严重影响受损组织再生与重塑,或导致肿瘤迅速发生。本项目拟以肝脏为研究对象,聚焦Hippo相关信号网络如何感知器官大小并适时调控细胞生长、分化与死亡以实现器官发育、再生重塑和器官大小控制这一关键科学问题,整合基础、临床、药学领域的先进研究技术,拟通过基因编辑、内胚层干细胞肝向分化、肝细胞移植和肝脏重建、肝脏损伤修复等模型、临床病理分析、蛋白结构解析和靶向药物设计等方法,深入探讨该通路失控导致肝脏发育异常、再生重塑障碍、癌症发生的致病机理,并提出靶向干预新策略。控制肝脏组织发育、再生重塑与大小的关键蛋白质机器(2017YFA0504500

Establishment of MDCK cell lines which stably express visualable human neonatal Fc receptor

[目的]建立稳定表达融合EGFP的人新生儿Fc受体（h FcRn）的MDCK细胞株。[方法]构建重组慢病毒质粒p EGFP-h FcRn,采用四质粒包装系统共转染HEK 293T细胞生产重组慢病毒,感染MDCK细胞后对EGFP阳性细胞进行流式单细胞分选;通过Western Blot及EGFP-β2m荧光共定位验证h FcRn的完整性,并用流式细胞仪检测h FcRn与人Ig G的结合活性。[结果]测序结果表明成功构建p EGFP-FcRn慢病毒表达载体;感染后EGFP阳性MDCK细胞比例约为26.5%,流式单细胞分选后得到纯阳性细胞;荧光共定位及Western Blot均检测到h FcRn的完整表达;流式分析表明细胞株上的h FcRn与Ig G存在p H依赖性结合。[结论]成功获得稳定表达具有生物活性的可视化h FcRn的MDCK细胞株。[ Objective] To establish MDCK cell line stably expressing EGFP- human neonatal Fc receptor（hFcRn） fusion protein. [ Methods ] The lentiviral expression vector for EGFP - hFcRn fusion protein was constructed. Generating by co - transfection of four -plasmids into HEK 293T cells ,the lentivirus particles were used to infect MDCK cell line. EGFP positive single cell was obtained by FACS, and then FcRn expression was identified by fluorescence co -location with EGFP - β2m and confirmed by Western Blot. Flow cytometry was used to detect binding activity of hFcRn and human IgG. [ Results ] DNA se- quencing demonstrated that the lentivirus vector pEGFP - FcRn was constructed successfully. The percentage of EGFP - posi- tive ceils was about 26.5% after infection. Expression of the complete protein was detected through fluorescence co - location and Western Blot, respectively. Flow cytometry analysis showed that the cell lines could pH - dependently capture human IgG. [ Conclusion] MDCK cell line stably expressing functional visualable hFcRn was established.基金项目：国家自然科学基金项目（“结构生物学指导的HBV治疗性抗体人源化及其关键技术研究”,No.31600748;“抗呼吸道合胞病毒高中和活性抗体的保护机制研究”,No.81401668;“基于广谱中和单抗的通用型流感疫苗设计及其结构基础研究”,No.31670934

距踝关节的三维有限元分析——足球踝发生的生物力学特点

目的:应用三维有限元的计算分析方法,研究踝关节在不同体位、不同载荷的条件下,距踝关节软骨表面的应力变量,揭示足球踝发生的生物力学规律。方法:将正常男性足踝部的CT扫描数据,导入三维建模软件建立几何模型后,进行有限元网格划分。分析踝关节在跖屈45°、35°体位下,远距离和近距离踢球时,距骨表面的应力分布数据。结果:①成功创立踝关节跖屈45°、35°两组三维有限元模型。前者:220876个节点,1280039个单元,后者:178163个节点,1036740个单元。②经计算得到踝关节4种工况的von-mises应力云图。结论:①胫距和距腓关节面,是足球踝软骨损伤与炎症的好发部位。②如运动员以踝关节跖屈45°位姿势踢球,可减少足球踝的发生率

Research progress of high voltage electrolyte for lithium-ion batteries

随着对锂离子电池能量密度要求的提高,新一代高电压锂离子电池和与之匹配的高电压电解液的研究开发也日益受到重视。从优化电解液的组成和使用具有特殊功能的新型溶剂、添加剂等方面对锂离子电池高电压电解液的研究进行分析和总结,并对未来的应用前景进行展望。With the increasing requirements for the lithium-ion battery energy density, more and more attentions are focused on the research and development of a new generation of high voltage lithium-ion battery and high voltage electrolyte.The recent research progress related to high voltage electrolyte solutions was analyzed and summarized from the electrolyte composition, special solvent and additives