阀芯槽及倒角磨床的研制

本文介绍的XYJ-2015阀芯槽及倒角磨床是最新为汽车行业开发的高效磨削机床,该机床为五轴三联动数控磨床,采用双磨头、双工位,一次装夹,完成工件不同部位的磨削加工.缩短了辅助工作时间,提高了加工质量,可以替代国外同类设备.     

正面角焊缝断裂原因分析

对正面角焊缝断裂原因进行了分析，在角焊缝处对最大剪应力面进行了探讨，试验证明断裂面位置与最大剪应力面是吻合的，同时运用图解等方法，进一步验证加大沿载荷方向的焊脚尺寸，可提高接头强度。     

强化汽车齿轮的有效途径：计算顶隙与齿轮弯曲强度

文章提出了计算顶隙的概述一面分析后指出计算隙可以极大地提高齿轮的承载能力，为产品设计人员设计高强度齿轮提供了一种行之有效设计方法。     

A control system for uniform bead in fillet arc welding on tack welds

Positioning a workpiece accurately and preventing weld distortion, tack welding is often adopted before main welding in the construction of welded structures. However, this tack weld deteriorates the final weld bead profile, so that the grinding process is usually performed for a uniform weld bead profile. In this study, a control system for uniform weld bead is proposed for the fillet arc welding on tack welds. The system consists of GMA welding machine, torch manipulator, laser vision sensor for measuring the tack weld size and the database for optimal welding conditions. Experiments have been performed for constructing the database and for evaluating the control capability of the system. It has been shown that the system has the capability to smooth the bead at the high level of quality.     

基于广义强度模型的T型钢桁架节点断裂分析

利用通用软件ANSYS的二次开发功能,将静水应力型广义屈服模型编制成子程序模块。对直角角焊缝进行了基于广义强度模型的数值模拟,以建议的椭球面断裂准则为判据,提出了等效考虑焊接缺陷和残余应力的断裂因子CI的修正系数k。基于修正后的断裂因子CI,对T型钢桁架下弦一般节点进行断裂分析,得出了防止T型钢桁架节点脆断的细部构造。     

D114柴油机曲轴圆角淬硬磨削工艺

D114柴油机曲轴原采用精加工后软氮化工艺,不仅主轴颈跳动难以达到图纸要求,而且曲轴综合性能不高,成为114柴油机发展的一大主要问题。圆角淬硬曲轴是柴油机曲轴的发展方向,但磨削后在主轴颈、连杆颈易产生表面烧伤及磨削裂纹等现象。本文主要介绍圆角淬火曲轴磨削工艺的攻关过程及解决方案。     

弹性针布去氧化光洁处理的探索

提出一种去氧化光洁处理的方法，能简便、有效地解决弹性针布钢针经高频淬火后产生的针尖锈蚀问题。     

变宽度板承受拉伸和弯曲时的三维应力集中

根据Hellinger Reissner原理 ,建立了具有一个无外力圆柱面的三维杂交应力元 ,元内假定应力场满足以柱坐标表示的三维平衡方程及无外力圆柱面上外力边界条件 ,当元退化为二维时也满足协调条件。单元位移场与相邻元协调。数值算例表明 ,现在的特殊杂交应力元 ,在相当粗的网格下即能高效地分析变宽度厚 (薄 )板的三维及二维应力集中。     

Bolted large seismic steel beam-to-column connections Part 1: experimental study

Two large bolted steel moment-resisting connections were studied by experiments. These connections were single-sided beam-to-column assemblies that are representative of exterior beam-to-column connections, and they were composed of W36×150 Grade 50 beams and W14×283 Grade 50 columns. T-stubs were cut from W40×264 sections of Grade 50 steel. The T-stub stems were welded to the beams and prestressed by bolts to the beam flanges in the shop. Final beam-to-column assembly required no additional welding: the T-stub flanges were bolted to the column and the column shear tab was bolted to the beam web. The specimens had two symmetrically located T-stubs with different stem geometry: Specimen 1 had rectangular-shaped stems, whereas Specimen 2 had U-shaped stems. During the cyclic testing the beam deformation was minimal controlled by active participation of the T-stub flanges: a separation between T-stub flanges and the column flanges was observed. This separation was caused by bending plastic deformation in the T-stub flanges and plastic deformation in the high-strength bolts. This phenomenon allowed energy dissipation and prevented severe buckling of the beam flanges and beam web.