汽车前梁内高压成形工艺分析

传统汽车前梁的制造一般是板料冲压成形,它的缺点是成形工序多,模具结构复杂。内高压成形汽车前梁具有工艺简单,生产费用低,成形零件强度与刚度高的优点。采用有限元分析方法对汽车前梁内高压成形过程进行了模拟分析,研究了预弯曲形状和内高压压力对零件成形质量的影响。结果表明:坯料形状对零件胀形质量有重要影响,完全预弯成形后零件胀形质量较好;内高压压力过大会使零件破裂,过小会造成胀形不足;当内高压压力为70 MPa时,可成形出质量较好的零件。     

空气罐封头的压形模具设计

零件的局部成形在实际生产中应用较多，在零件的形状与材料确定时，其成形质量主要取决于成形工艺和模具结构。当零件的成形工艺性较差时，就要通过改进工艺和模具结构的方法来保证零件质量。本文介绍了空气罐封头压形工艺与模具结构的改进工艺，改进后的模具改善了成形缺陷，保证了零件质量。     

复杂杯杆型零件成形工艺的比较研究

采用基于热力耦合的刚粘塑性有限元方法对复杂杯杆型典型零件－－钏形罩预成形件多种温热成形工艺进行了有限元仿真，得到了变形流动规律和力能参数，并进行了相关实验研究，其结果对复杂杯杆型零件温热成形工艺的选择有指导和参考作用。     

铝茶壶嘴成形工艺与胀形模设计

铝茶壶嘴形状复杂,其成形工艺也复杂,需要多道工序.成形中冷作硬化现象严重,容易发生胀裂.通过对零件的分析,利用零件成形工序的特征,设计了组合穿孔的胀形模,较好地控制了胀形中易出现的胀裂现象,提高了生产效率,保证了零件的质量.该没计对同类产品具有一定的参考价值.     

SY－1041轻型车桥壳成形工艺设计

简述了ＳＹ—１０４１型轻型货车的后桥壳本体零件的高精度要求和成形的复杂性。分析了桥壳本体零件弯曲成形的变形特点，计算了回弹值和修边弹胀系数，进而确定了桥壳本体的成形工艺方案和工艺设计的主要参数，为模具设计提供了设计基础。     

汽车万向节叉零件成形工艺设计

分析了汽车万向节叉零件成形工艺,该万向节叉成形是由落料、裁口切断（一模两件）、弯曲、压弧、卷圆及弯曲成形6道冲压工序,再经过7道机加工序来完成整个制件。此制件是由精确计算和分解成多道工序而完成的。     

抛物线形零件的成形工艺与模具设计

简要介绍了抛物线形零件的成形工艺，详细叙述了该零件的拉伸工艺及模具结构设计。     

复杂薄壁微小截面环形件的充液成形技术研究

针对具有微小特征尺寸的复杂薄壁环形零件提出了轴向进给与充液胀形相结合的多级充液成形工艺方法.以通用有限元软件ABAQUS为平台建立数值模拟模型,基于建立的模型对复杂环形零件的成形工艺进行模拟,分析了液室压力加载曲线、模具的摩擦系数、开模间距等工艺条件对成形的影响,得出开模间距和液室压力是影响成形结果的主要因素,最终给出...     

立体三通管复合成形工艺分析及成形力的计算

论述了立体三通管挤压胀形与弯曲复合成形工艺，分析了三通管接头挤压胀形力和弯曲力的理论计算公式，通过成形内径小于10mm的立体三通管样件，作了试验研究验证。     

小圆圈零件弯曲成形模设计

小圆圈零件弯曲成形模设计湘潭机电高等专科学校（湖南湘潭４１１１０１）彭庚新１引言图１是轴承套零件,材料为紫铜,料厚０．８ｍｍ,外径５ｍｍ。该零件圆柱度要求较高,且外形尺寸较小,属于小圆圈弯曲件,对于小圆圈弯曲件,其成形工艺一般是先弯成Ｕ形,然后再弯成...     

Dynamics of a heterogeneous polymer system obtained as a result of a conductor explosion

The performed studies allowed us to obtain a composite with regulated structure formation at ?? ?? 0.06 vol % of copper and directed changes of the electrophysical properties in a dielectric using the explosion of a conductor.     

Dynamics of a magnetization-reversal nucleus in a ferromagnet

This paper is devoted to a theoretical investigation of the effect of an applied magnetic field and damping on the dynamics of magnetization-reversal nucleus represented by interacting domain walls (DWs) with opposite topological charges. It is shown that at initial amplitudes that are less than the amplitude of the critical nucleus of magnetization reversal, nonlinear vibrations of strongly interacting DWs are observed. In the presence of dissipation, the nonlinear vibrations are damped vibrations with a frequency that changes with time. At the initial amplitudes that are greater than the amplitude of the critical nucleus, the magnetization-reversal nucleus decays with the formation of a solitary domain. The motion of two interacting 180° DWs relative to their common immobile center in fields that are less than the Walker field is translational; in higher fields, it is oscillatory. It is shown that DW vibrations are accompanied by a periodic transformation of their structure from Bloch into Néel and vice versa with a frequency that depends on the field, damping, quality factor, and the initial amplitude of the magnetization-reversal nucleus.     

Study of a Neural Network with a Meta-layer

We consider the network studied by Amit et al. (i.e. a network that is quite closely related to the Hopfield model). We show that it is possible to save a significant amount of connections if it is reinterpreted as a two-layer system. One of the layers can be interpreted as the basis layer and the other one as a meta-layer. This system is suited for the storage of orthogonal groundstates. However, an extension of the meta-layer allows one to store mixture-states (multicomponent states) as well. This bears a system in which taxonomies as well as looser associative links can be stored. Due to the topological properties of the mixture-states, the system can be provided with a learning rule according to which the memories reorganize in a way that is suited for some aspects of genetic psychology     

Cracking of a Cobalt-Based Hardfacing of a Gate Valve Disk in a Desalination Power Plant

Cobalt-based alloys of the Stellite family are used as hardfacing for sealing surfaces of valves operating in desalination and power plants because of their excellent low friction and anti-galling properties in high-load sliding contact under the prevailing conditions. However, insufficient control of pressure and temperature during operation can degrade the integrity of the hardfaced material thus leading to its premature failure. This article presents a failure investigation carried out on the disk of a main stop gate valve that was used in a desalination plant. The disk was manufactured from X20 as a substrate material and a cobalt-based alloy for hardfacing. The cobalt-based hardfacing suffered from many surface and subsurface cracks that degraded its integrity. It was concluded that high-pressure steam flowing against the disk had tilted it and, thus, disturbed the alignment between the surfaces of the disk and the seat, leading to wear and large frictional heat that resulted in the degradation of the microstructure of the hardfacing layer and formation of the observed cracks.