基于Workbench的修井作业车吊卡有限元分析

为了提高高温条件下修井的作业效率及自动化程度,设计了一种新型自动吊卡,并对吊卡关键部位进行了强度分析.在确定修井机吊卡结构和工作原理的基础上,利用Solidworks对吊卡体进行建模,并利用ANSYS Workbench有限元软件对吊卡载荷状况进行模拟加载及分析计算,得到了吊卡的静力学强度、形变状态和疲劳寿命的分析结果,并获得了应力云图及相应数据.仿真结果表明,吊卡的静力强度、疲劳寿命有限元计算结果符合工作要求,稳定可靠,可为吊卡的工程应用提供参考.     

Cracks coalescence mechanism and cracks propagation paths in rock-like specimens containing pre-existing random cracks under compression

The mechanism of cracks propagation and cracks coalescence due to compressive loading of the brittle substances containing pre-existing cracks （flaws） was modeled experimentally using specially made rock-like specimens from Portland Pozzolana Cement （PPC）. The breakage process of the specimens was studied by inserting single and double flaws with different inclination angles at the center and applying uniaxial compressive stress at both ends of the specimen. The first crack was oriented at 50＆#176; from the horizontal direction and kept constant throughout the analysis while the orientation of the second crack was changed. It is experimentally observed that the wing cracks are produced at the first stage of loading and start their propagation toward the direction of uniaxial compressive loading. The secondary cracks may also be produced in form of quasi-coplanar and/or oblique cracks in a stable manner. The secondary cracks may eventually continue their propagation in the direction of maximum principle stress. These experimental works were also simulated numerically by a modified higher order displacement discontinuity method and the cracks propagation and cracks coalescence were studied based on Mode I and Mode II stress intensity factors （SIFs）. It is concluded that the wing cracks initiation stresses for the specimens change from 11.3 to 14.1 MPain the case of numerical simulations and from 7.3 to 13.8 MPa in the case of experimental works. It is observed that cracks coalescence stresses change from 21.8 to 25.3 MPa and from 19.5 to 21.8 MPa in the numerical and experimental analyses, respectively. Comparing some of the numerical and experimental results with those recently cited in the literature validates the results obtained by the proposed study. Finally, a numerical simulation was accomplished to study the effect of confining pressure on the crack propagation process, showing that the SIFs increase and the crack initiation angles change in this case.     

考虑基于变分模态分解的冲击载荷截止因数影响的管系响应

针对海上浮式装置力学分析中选用不同截止频率阈值得到重构的冲击载荷对结构响应结果有较大影响的问题,采用变分模态分解(Variable Mode Decomposition, VMD)方法得到冲击载荷各本征模态函数、对应频谱的特征频率和最大加速度幅值。选取不同的截止因数,重构得到不同的冲击载荷。数值仿真结果表明：当截止因数为0.01时,重构的冲击载荷动力学响应与原始冲击载荷动力学响应基本保持一致;在保证足够的安全裕度的前提下,当截止因数选0.20时,可获得更低的截止频率。     

压力加工机械载荷与轴温的监测

分析了压力加工载荷和轴温监测的基本要求，介绍了载荷和轴温测量的原理与技术，说明了监测方案的设计及实施方法。     

转炉托圈机械应力和热应力的有限元计算与分析

应用有限单元法对１８０ｔ转炉托圈进行了机械应力和热应力计算，并分析了应力分布和变化规律，为转炉托圈的设计和使用提供了参考数据。     

直列六缸柴油机曲轴平衡性分析

在外部平衡性良好的曲轴上加装平衡重,通常是为了减小曲轴所受弯矩,但是平衡重的安装将影响主轴承载荷的大小和分布,平衡重的施加还影响曲轴的内弯矩.本文分别采用了对曲柄臂施加四平衡重和八平衡重两种平衡方案进行对比.     

小冲杆测试材料屈服载荷的有限元分析

文章通过ABAQUS有限元分析软件模拟小冲杆试验过程,重点分析2.25Cr1Mo、16MnR、20#、1.25Cr0.5Mo4种材料的小冲杆屈服载荷。试验结果表明,有限元模拟得到的材料屈服载荷与常规拉伸试验所得出的屈服强度存在显著的线性关系,并具有相当高的相关系数。为最终通过小冲杆试验评价材料的屈服强度提供了一条新的思路。     

大型齿轮铸造

<正> 轧机减速器大齿轮一般是双层(或三层)辐板人字齿的大型齿轮,结构复杂,承受载荷大,对材质和制造质量都要求很高.沈阳重型机器厂生产的轧机减速器大齿轮有数十个,其中最大的如图1所示,直径为4700mm,高度为1470mm,轮缘厚度为200mm,轮毂直径为950mm,轮毂厚度为210mm,辐板三层、厚90mm,毛重60t,材质为ZG35CrMo.     

泡沫铝层合圆管纵向和横向压缩力学性能研究

用碳化硅颗粒增强泡沫铝为夹芯,不锈钢圆管为面板制备层合圆管,研究了层合圆管在准静态压缩条件下的纵向和横向变形行为和能量吸收性能.研究表明,层合圆管的纵向压缩变形方式与空管相比发生了改变,由不对称变形模式变为轴对称变形模式;载荷-位移曲线平台段锯齿形波动与曲屈圈的形成呈现对应关系;层合圆管纵向和横向的吸能能力均远大于不锈钢圆管和泡沫铝吸收的能量之和,并且随着应变的增加,层合圆管的吸能能力增加更为快速;层合圆管在保持泡沫铝轻质的同时,在纵向和横向两个方向上均大幅度提高泡沫铝的吸能能力.     

激光熔覆MoS2/TiC/Ni减摩耐磨复合涂层组织及磨损性能的研究

以MoS2、TiC、Ni粉为原料,在20钢基材表面利用激光熔覆技术制备了减摩耐磨复合涂层.采用SEM和XRD对复合涂层的组织和相组成进行了研究,结果表明复合涂层主要由部分未熔的TiC颗粒、Mo2C、γ镍基固溶体和多种两元、三元硫化物TiS、NiS、Ni3Ti4S8等组成.用FALEX-6摩擦磨损实验机对MoS2/TiC/Ni复合涂层、MoS2/Ni激光熔覆层以及45钢的耐磨性能进行了对比,并对三种试样表面的磨损形貌进行了SEM观察.实验表明:MoS2/Ni激光熔覆层具有最低的摩擦系数,但磨损失重最大;MoS2/TiC/Ni复合涂层在载荷17.8N、转速200r/min条件下,磨损40分钟,其磨损失重仅为45钢的1/6.