管材径压胀形技术

阐述了管材径压胀形工作原理,归纳了该技术相对自然胀形技术的优越性。重点介绍了近年来利用管材径压胀形技术将管材截面胀形成三角形、矩形和梯形时,管材胀形规律及变形特点的研究现状。最后指出了管材径压胀形技术的发展方向和亟待解决的问题。     

液压胀形机拉力计算

简单介绍了液压胀形机的结构和工作原理,通过对胀形时工件的受力分析,用能量法推导出液压胀形机拉力的计算公式.     

汽车减振器储油缸筒的局部橡胶胀形加工

介绍了采用橡胶局部胀形加工汽车减振器储油缸筒的加工方法和胀形模具。     

小型桥壳液压胀形初始变形条件分析及成形试验

介绍了小型汽车桥壳的液压胀形工艺,提出了初始胀形内压的表达式,预测了初始胀形内压与轴向推力的匹配关系（即经向应力比的大小）对预胀形时各部分变形顺序的影响。在普通液压机上进行了两种加载路径下的液压胀形试验,在初始经向应力比小于零并保持恒内压的条件下,预胀形管坯先变形成两侧高、中部低的双鼓形,经增压后将中部胀起;在初始经向应力比大于零且内压恒定的条件下,预胀形管坯中部沿轴向胀裂;两种加载路径下,管坯扁锥体凸起与胀形区之间均产生了明显内凹缺陷。理论分析与试验结果均表明,初始变形条件对小型桥壳的预胀形有重要影响。     

管子液压胀形工艺的缺陷分析及对策

简单介绍了液压胀形工艺的基本原理及过程,通过动态显式有限元软件DYNAFORM模拟了管子液压胀形过程中可能出现的缺陷,对各缺陷的成因逐一进行了分析,并提出了对策及预防措施,为液压胀形技术的应用提供参考.     

蘑菇形顶盖的胀形模设计

胀形工艺常采用钢模胀形、橡皮胀形和液压胀形等。若采用钢模胀形会使凸模的分瓣数增多,制件外观质量难以保证,并且模具结构复杂,给使用和维修带来不便。利用聚氨酯橡胶压缩变形时作用在坯料上的力, 使节板料产生分离或塑性变形而获得合格的零件。采用橡皮胀形既能保证制件的形状和表面质量要求,又使模具结构简单,制造容易,同时也给使用和维修带来方便。本文以蘑菇形顶盖聚氨酯橡胶胀形模为例,介绍橡皮胀形模中的一些小窍门。     

驱动桥壳整体复合胀形工艺及液压机系统开发

在介绍现有驱动桥壳成形技术基础上,提出了一种新的驱动桥壳整体复合胀形工艺。针对与该工艺相匹配的核心工序,整体复合胀形的变形过程,采用有限元法进行了验证分析,获得了开槽管坯胀形温度为600℃时,胀形过程最大应力值达到243 MPa,能够满足驱动桥壳成形需求。结合胀形成形的功能需求和变形分析数据,通过集成中频加热炉、传送带、机械手等辅助装备,开发出驱动桥壳整体复合胀形液压机系统。可在同一平台上实现复杂的工艺过程,可实现不同型号驱动桥壳制造。     

燃料组件上管座锁定螺栓胀形模具优化设计

介绍了AFA3G燃料组件修复后,上管座锁定螺栓胀形的基本原理,并采用有限元方法,对胀形的模具进行优化设计,避免了锁定螺栓出现胀裂、褶皱等现象,通过实际验证,满足使用要求。     

撕口-胀形的分析与模具设计

介绍了板材撕口、胀形加工方法的应用，分析了实现该加工方法的各种影响因素，并提出了撕口、胀形模具的改进方案。     

非规则斜锥矩形件的拉深与胀形成形

本文介绍了一种非规则斜锥矩表件应用拉深与胀形的成形机理，坯伯通过拉深与胀形的复合成形方法获得了成形效果。     

基于金属圆管扩胀变形的碰撞波形发生器设计

为模拟碰撞实验中的加速度波形的要求,以金属圆管扩胀变形原理,通过不同壁厚圆管的分段组合形式研究了波形发生器的设计方法.用实物的标定实验和有限元仿真计算相结合的方法,运用正交实验设计方法,分析了金属圆管扩胀变形的影响因素,并分析了壁厚、扩径量、碰撞质量等主要因素的影响规律.结合实际的算例,验证了设计方法的有效性.相关结论可以为类似的碰撞波形发生器的设计提供理论参考.     

Static and dynamic axial crushing of foam-filled sheet metal tubes

Experimental results are provided for the quasi-static and dynamic axial crushing of thin-walled square and rectangular tubes manufactured from sheet metal. The tubes were tested both empty and filled with polyurethane foam of various densities. Both the stability and the energy absorbing characteristics of the tubes are described and discussed. Simple theoretical models are proposed to explain and quantify the interaction between the foam and the sheet metal tubes.     

双金属轧片式翅片管管外对流换热准则关系式研究

双金属轧制翅片管以其优良的传热性能、机械性能和耐腐蚀性能在许多工业领域，特别是炼油、化工、发电行业得到了广泛应用。影响双金属轧片式翅片管的传热性能的一个重要因素是管外气体一侧的对流换热系数。本文对双金属轧片式翅片管管外对流换热系数准测进行了研究，得到了一个精度较高的适用于各种规格双金属轧片式翅片管的通用的管外对流换热系数准则关系式。     

Electropolishing the bore of metal capillary tubes: A technique for adjusting the critical flow

A technique has been developed for electropolishing the bore of metal capillary tubes. Although developed specifically for stainless-steel tubes, the technique should be directly applicable to other metals. Tubes with inside diameter as small as 0.20 mm and 110 mm long have been successfully electropolished. The electropolishing technique can be used to increase the critical flow of a capillary tube in a controllable way.     

Plastic deformation mechanisms in axially compressed metal tubes used as impact energy absorbers

The characteristics of a number of metal components proposed as impact energy absorbers are reviewed, attention being focussed on to modes of deformation which stem from the axial compression of metal tubes. Progressive buckling, inversion and splitting are discussed and areas for future work identified. The buckling of thin-walled square section tubes filled with polyurethane foam is also described. Reference is also made to recent work on cellular materials which highlights the influence of inertia in axially compressed tubes and tubular arrays.     

轴压翻管力及其影响因素的分析

根据金属成形理论和圆管在外翻管变形过程中，壁厚保持不变、翻管力恒定等实验现象，志出在圆角模上外翻管的翻管力Ｐ、最佳圆角半径ｒｉ的表达式，论述翻管模具半径等对翻管力的影响。确定了在轴压力作用下，圆管发生失稳，翻转、端部撕裂３种变形模式的模具半径范围。     

Axial crushing of foam-filled tapered sheet metal tubes

Following earlier work on the axial crushing of foam-filled sheet metal tubes of square and rectangular cross-section and empty tapered tubes the behaviour of foam-filled tapered tubes is considered. Theoretical estimates of the variation in the mean crushing loads for both quasi-static and dynamic loading conditions are provided and compared with experimental data.     

金属波纹管单点增量成形过程研究

将单点增量成形技术引入金属波纹管成形,提出了一种金属波纹管单点增量成形工艺。基于ABAQUS/Explicit建立增量成形波纹管仿真模型,分析成形过程中成形力的演变,以及成形应力、材料局部变形位移和塑性应变分布的特点;建立了波纹管单点增量成形实验平台,采集成形过程数据并分析实验数据。结果表明：X向分力在增量成形管壁中的数值最大,其次是Y向分力和Z向分力;斜面拉伸区和圆弧过渡区的塑性应变大,该区域管壁容易发生过度减薄和断裂。     

Energy absorbing capacities of braced metal tubes

The collapse and energy dissipation characteristics of metal tubes braced with tension members are considered experimentally and load bounding techniques are employed to estimate collapse loads of such tubes. The results are applied in the full scale crash testing of a vehicle impact attenuation device composed of clusters of steel tubes and subjected to high speed roadway collisions.     

Static and dynamic crushing of tapered sheet metal tubes of rectangular cross-section

The use of tapered sheet metal tubes as impact energy absorbers is considered. Their behaviour is compared with tubes of uniform cross-section with regard to the stability of the gross deformation modes. Single-tapered and double-tapered tubes are considered and estimates of the variation of their mean crushing forces with reduction in length under both quasi-static and dynamic axial loading conditions are provided. The practically important question of the response of tapered tubes to oblique impact loads is also considered.