On the study of the stress-strain state of the IVV.10M reactor vessel and in-vessel components under seismic impacts

The problem of the seismic stability of the new IVV.10M research reactor is considered. To computationally prove the viability of the engineering solutions, a detailed finite element model of a reactor is developed in strict accordance with the design documentation. The model represents the actual interrelations between all load-carrying elements and loads acting on the structure. A computational investigation of the stress-strain state of a reactor is carried out using the ANSYS bundled software. The natural oscillation frequencies and natural mode shapes of the structure are determined by linear-spectral analysis. The dynamic impacts occurring under seismic conditions are computed taking into consideration the actual response spectra. The most heavily loaded sectors in the reactor vessel and in-vessel components are established. A quantitative assessment of the stress-strain-state parameters in the crucial regions of the reactor is carried out. The computational results are compared with the figures of the normative documents currently in force in domestic nuclear-power engineering.     

焊接残余应力对结构性能的影响

以焊接残余应力为研究对象,讨论了残余应力对于结构静强度、疲劳强度、应力腐蚀性和稳定性的影响,指出残余应力的存在不影响结构的静态承载能力,但会促使结构发生脆性断裂、疲劳断裂、应力腐蚀断裂、失稳破坏等,应采取措施加以控制或消除。     

Seismic stability tests for models of fuel assemblies

A procedure and results of seismic stability tests of full-scale models for fuel assemblies of the water-water energetic reactor VVER-1000 are presented. In the course of tests, kinematic loading of fuel assembly supports has been carried out in accordance with accelerograms of the motion of fuel assembly supports during an earthquake, which was obtained by computational methods. Based on the results of measurements of the vibrational response of fuel assemblies, transfer characteristics between the response of fuel assemblies and applied action (support acceleration) are determined. The lack of a resonant response of fuel assemblies at seismic loads is found.     

基于Newmark-β法的非接触式机械密封轴向振动研究

振动对非接触式机械密封性能有着重要影响,如导致碰撞和泄漏。构建包括静环-液膜-动环-弹性元件的密封系统模型,探讨自由衰减振动、自激振动和地震极端振动3种激励下,密封系统静环、动环和弹性元件的位移以及密封系统泄漏和碰撞的情况。研究表明：在不受外界激励的情况下,在自由衰减振动下密封系统轴向稳定性和密封性能良好;密封系统在受到简谐振动激振力形式的自激振动干扰后,系统位移量明显增大,会显著影响密封性能;叠加一定地震烈度的随机平稳地震动影响下,弹性元件位移量大幅增加,密封失效。振动对非接触式机械密封性能的影响显著,应确保密封端面间液膜厚度稳定且足够小,以维持密封系统的长周期运转。     

地震落梁两级控制装置的开发与试验

为了增强桥梁抗御地震落梁的能力,减轻交通生命线系统的震害损失,基于耗能减震、多级设防和结构分灾三个抗震性能设计理念,设计了一种具有耗能限位和上部体系连续化两级功能,并能在不同水准地震下自动实现功能转换的地震落梁控制装置。首先,分析了装置的构成、特点和工作机理,对第1级耗能限位组件进行了拟静力试验,测试了耗能滞回曲线;然后,对第2级拉索连梁组件进行了静力拉伸试验,评价了其变形性能、破坏形式和锚固性能;最后,对抗震销栓进行了剪切试验,考察了控制级别的转换,采用试验结果对有限元模拟结果进行了验证。研究表明,地震落梁两级控制装置具有有效的位移约束、合理的耗能机制和明确的分灾保险丝构造,实现了梁-梁连接和墩-梁连接控制模式的优势互补,实现了强震作用下对桥梁落梁失效的控制和对桥墩的安全保护。     

Improvement of static characteristics of an aerostatic journal bearing using the elastic deformation of an O-ring

A new type of aerostatic journal bearing in which the elastic deformation of an O-ring is used to improve its static characteristics is proposed. The static characteristics of this bearing are determined theoretically by both the finite difference method and the small perturbation method. Effects of parameters on the static characteristics are shown, and the optimum design method for the static characteristics is discussed. Further, theoretical results are compared with experimental results to confirm the validity of theoretical predictions. It is consequently found that the new type of bearing possesses higher static stiffness and greater load capacity than conventional point source bearings with inherently compensated feeding holes.     

基于FEM的单臂塔式起重机模态及谐响应分析

塔式起重机是建筑施工领域中的重要起重设备,其工作稳定性与施工安全密切相连。为了验证塔式起重机结构的稳定性,通过FEM(有限元法)对某型塔式起重机模型的3种典型工况进行静动态特性分析,主要分析其静强度、模态、谐响应等方面。经过分析,该机静强度满足设计要求,振幅位移最大处主要位于起重臂和平衡臂的端部。通过模态分析可知该机固有频率较低,各阶频率相差不大,且在某些频率下与塔机易发生共振。因此,应加强起重臂和平衡臂端部的强度和刚度,并在塔式起重机工作过程中应避免共振频率,以免发生共振导致安全事故。     

大型组合管式反应塔的应力分析(二)--应力分析结果

在第一部分中建立的反应塔有限元模型基础上，依据．JB4732一1995《钢制压力容器-分析设计标准》，并通过合理有效的简化假设，对6种比较危险的组合工况，分别计算了组合管式反应塔中各危险截面的应力强度。对组合管式反应塔进行了强度和稳定性校核，确定了组合管式反应塔的主要强度尺寸，从而奠定了组合管式反应塔的设计基础。     

Buckling limit evaluations for reactor vessel of ABTR

We evaluated the buckling limit of a conceptually designed reactor vessel of the Advanced Burner Test Reactor (ABTR) for a horizontal safe shutdown earthquake (SSE) seismic load. In this evaluation, both seismic isolation and non-isolation designs were considered for thin reactor vessels subjected to elevated temperature services. For calculating the buckling load, two kinds of methods, a numerical simulation method using finite element analysis and an evaluation formula driven from a theoretical basis, were used. To consider the material aging effect caused by a 60-year design lifetime and 510°C normal operating temperature, an isochronous stress-strain curve corresponding to these conditions was used for the nonlinear elastic-plastic buckling analysis method. From the evaluation results of the buckling load, it was found that plasticity behavior significantly affects the buckling strength, but that the initial geometrical imperfections have little effect. Also, the non-seismic isolation design does not satisfy the buckling limit rules of the ASME BPV Section III, Subsection NH, but the seismic isolation design does satisfy it with sufficient margins.     

滑动丝杠螺母机构的可靠性设计

应用应力 -强度干涉模型 ,研究了滑动丝杠螺母机构的可靠性设计。它包括耐磨性、稳定性、刚度、强度的可靠性设计。     

新型推力滚子轴承的强度计算

对新型轴承的结构特点作了简单介绍,计算了各零件在工作寿命期间承受接触应力的循环次数,推导出了圆锥滚子轴承的接触应力、疲劳强度和静载强度的计算公式。同时又对滚子端面的小型推力球轴承推导出接触应力、疲劳强度和静载强度的计算公式。     

浮式起重机结构联合失效可靠性分析的混合模拟法

提出了一种将蒙特卡罗模拟法与响应面法相结合的混合模拟法,并考虑结构体系在强度、刚度和稳定性联合失效模式下进行可靠性分析.以巨型海上浮式起重机结构体系为例,计算得到其结构体系在静力作用状态下的联合失效概率和可靠性指标,证明了文中所述方法的可靠性和高效性.     

浅析增加板宽和板厚导致结构承载能力下降的问题

钢结构的强度承载能力主要由截面特性(截面积和惯性矩)决定,而稳定性承载能力主要由构造(加劲肋的大小和分布)决定。最优化的设计是保证构件强度承载能力和稳定性承载能力相当,即所谓的等强度设计原则。增加板宽和板厚(施工中经常出现的"以宽代窄"、"以厚代薄",即所谓的"以高代低","以强代弱"板的替代原则)会提升构件的强度承载能力,如果构造没有随之优化,则构件容易在屈服之前发生屈曲,使构件的稳定性承载能力降低。     

一种外壁带螺旋形导流板钢烟囱的结构强度分析

以一种外壁带螺旋形导流板的钢烟囱为研究对象,运用ANSYS Workbench和CFX流体力学,对其结构进行了风载荷作用下的稳定性及静力分析,并根据规范要求,对各个工况载荷作用下的Von mises应力进行了强度校核。通过与相同工况下的传统钢烟囱对比可知,该种改进型钢烟囱的结构更加安全稳定,为设计大高径比和高抗弯强度的钢烟囱提供了新的设计依据。     

34m复合材料风力发电机组叶片屈曲有限元分析

采用有限元分析的方法解决了叶片的静强度和屈曲稳定性问题.首先,阐述了利用MSC.Patran建立复合材料叶片的有限元模型的步骤和方法;其次,利用蔡-吴(E.M.Wu)失效准则和Hill-蔡(S.W.Tsai)强度理论校核了几种主要承力材料的强度;最后,结合有限元二阶屈曲模态计算结果,讨论了风机叶片结构的屈曲稳定性.     

Shear behaviour of brick-mortar interface in CFRP retrofitted or repaired masonry

There are many unreinforced masonry buildings all over the world. Many of them are located in seismic zones and are, therefore, susceptible to lateral forces caused by earthquakes. The transmission of these forces to the foundations is made through load bearing walls and depends on the shear strength and stiffness of masonry.In plane shear strength of load bearing masonry walls depends on many factors like the bricks and mortar strength and the way the wall is constructed. It is mainly due to shear strength of the brick-mortar interface given by the adhesion and by the friction caused by normal compression loads. Under severe seismic loads the ultimate strength capacity of the interface is achieved and the structure collapses.The results of an experimental program performed to study the shear behaviour of CFRP retrofitted and repaired masonry are presented in this paper. Increase of strength, ductility and stiffness due to the addition of CFRP laminas is specially analyzed. Specimens formed by three bricks and two mortar joints without reinforcement, retrofitted and repaired with CFRP laminas were tested under quasi-static and cyclic load.Additionally, the numerical study of the same specimens is presented. The specimens were modelled with 2D and 3D finite elements programs. Orthotropic plasticity models were used for bricks and mortar, including brick-mortar interfaces and CFRP laminas. Experimental results were used to calibrate the parameters of the material models and a numerical tool for the mechanical analysis of retrofitted or repaired masonry panels was developed. A parametric numerical study was also carried out with these numerical models in order to obtain the optimal dimensions and orientation of the reinforcing bands.     

新型太阳能热水器的力学分析及优化设计

针对太阳能热水器安装人员提出的现行太阳能热水器支架螺栓较多、易松动、安装不便,导致安装效率低下问题,研究出一种在不降低承载能力和使用效果情况下,通过减少螺栓数量或改变部件连接结构,提高现场工作人员的安装效率,降低安装成本的新型太阳能支架。方案确定后利用UG建模,并将模型导入Workbench进行静力学分析,并利用ANSYS DesignXplorer进行结构优化根据优化结果对设计方案进行修改,从而达到优化设计的目的,为结构的合理设计与改进提供了可靠的依据。     

单立柱巷道堆垛机满载下的静力分析

堆垛机是自动化立体仓库的重要装卸机械,堆垛机的力学性能（如静强度）对于实现立体仓库中作业自动化的有效性与可靠性都有着显著的影响。单立柱巷道堆垛机的静力分析主要是确定机体的静强度和静刚度,也就是指在外加静态力作用下堆垛机机体的变形情况。通过应用有限元软件ANSYS对堆垛机机架结构进行强度和刚度的静力分析,可以得出立柱、下横梁和载货台在静载下应力的最大值及分布情况。通过对图形或数据进行分析,使机体各个部位的变形和受力情况尽量均衡,并与理论的许用值进行比较,得出堆垛机在满载状况下其结构具有稳定性[1-3]。     

80 t级散装水泥罐车的研制

80t级散装水泥罐车是为增加车辆载重、提高铁路货物运输能力而研制的新型重载罐车,该车装用27t轴重下交叉支撑转向架,采用三个V型气室流化床结构,具有载重大、运营速度高、卸净率高.文章详细的介绍了该车的结构组成,并对车体进行了静强度分析,结果表明研制的车体满足设计要求.     

微极流体对错位轴承的润滑性能研究

错位轴承比普通径向轴承表现出了更好的性能,因此对错位轴承的静态性能和动态性能的研究具有重要意义。推导了微极性润滑时错位圆和错位椭圆轴承的动静特性方程,采用有限差分法计算微极错位圆和错位椭圆的静特性,同时采用偏导数法计算其动特性,研究耦合数和特征长度对轴承性能的影响。结果表明：随耦合数增大,错位圆和错位椭圆轴承承载力和摩擦力增大、摩擦因数减小、刚度系数和阻尼系数绝对值增大,轴承稳定性提高;随特征长度增大,错位圆和错位椭圆轴承承载能力和摩擦力减小、摩擦因数先减小再增大、刚度系数和阻尼系数绝对值减小,轴承稳定性降低;相比于牛顿流体,微极流体的承载力更大,摩擦因数更小;微极流体会加大轴承的阻尼系数和刚度系数的绝对值,并且会提高轴承的稳定性;与错位圆轴承相比,错位椭圆轴承承载力大、摩擦力大但是摩擦因数小、稳定性更好。