数控肋骨冷弯机成型控制参数实时计算与控制研究

实时控制是数控肋骨冷弯机的关键技术之一.通过对型材冷弯成型实时控制问题的研究,建立一种肋骨冷弯成型加工适应控制模型,根据一种基于大地坐标系的新型检测装置,给出了加工参数实时计算方法.该方法已用于数控肋骨冷弯机的制造,显著提高了冷弯机的智能化水平.     

冷弯成型过程的有限元模拟

概述了冷弯成型过程有限元数值模拟的基本原理和基本算法，利用ANSYS／LS—DYNA分析软件对冷弯过程进行有限元数值模拟，并对模拟结果进行受力和应变分析以验证其可行性和正确性，为冷弯成型的工程设计提供了科学依据，从而降低设计风险。     

新型钢门窗型材冷弯成型CAPP中的工艺生成方法

根据薄壁空腹钢门窗型材及其冷弯成型工艺的特点，在新型薄壁空腹钢门窗型材冷弯成型ＣＡＰＰ／型辊ＣＡＤ一体化系统中综合应用检索、变异、创成方法来生成型材的冷弯成型工艺，使系统实用、使用方便、运行快捷且具有一定的智能性，对应用ＥＳ思想和方法生成成型工艺的方法进行了较详细地介绍。     

PLC在型材弯曲成形中的应用

以型材弯曲成型机械———肋骨冷弯机为例,介绍了PLC在型材弯曲中的应用,同时对其安全性、可靠性进行了分析,对其应用中要注意的技术问题作了论述说明。     

250 t肋骨冷弯机设计及机架结构强度计算

介绍了２５０ｔ肋骨冷弯机技术性能以及结构特点，２５０ｔ肋骨冷弯机能满足船厂造船能力为３万ｔ船舶的需要，并在传统肋骨冷弯机基础上对其结构做了大量的改进和完善。改进后的肋骨冷弯机机构更简单、性能更可靠、操作维修更方便。对设计后的机架结构强度进行了校核，中机架、侧机架满足结构强度要求。     

程控机械手肋骨冷弯机PLC控制系统的抗干扰设计

提高控制系统的抗干扰能力可以提高它的稳定性和可靠性．文中分析了程控机械手肋骨冷弯机的PLC控制系统的内部干扰源及外部干扰源，从系统供电，输入输出信号，系统接地及电缆敷设等四个方面提出了抗干扰措施，并以青山船厂160t程控机械手肋骨冷弯机的控制系统为例，说明这些措施对提高系统的抗干扰能力和系统的可靠性有着十分重要的作用．     

黄铜管焊缝高温短时退火组织的研究

用光镜对单相黄铜管焊后和冷变形后的焊缝在高温短时退火后的组织进行了研究。结果表明，焊后不经过冷变形的焊缝，退火后组织为粗大的、并垂直于焊缝的条形晶粒和粗大的等轴晶粒；经过冷变形后，焊缝的不同原始组织在退火后都将发生再结晶，影响管坯表面质量的铸造组织消失，组织细化，文中对试验结果进行了分析．     

基于不同成型方式的沥青混合料性能研究

基于Superpave旋转压实和马歇尔击实成型方法,简单介绍了Superpave沥青混合料配合比的设计过程,并通过车辙试验、小梁弯曲试验、冻融劈裂试验及浸水马歇尔试验,对比分析了在两种不同成型方式下AC-20沥青混合料最佳油石比、高温抗变形、低温抗开裂及水稳定性能差异,结果表明:成型方式对沥青混合料性能影响显著,采用旋转压实成型沥青混合料确定的最佳油石比要小于马歇尔击实方法,且动稳定度提升约26%,冻融劈裂比及残留稳定度升高约2%,破坏弯拉应变基本相同,综合路用性能更优。     

钢丝网加筋水泥稳定碎石梁加筋试验分析

冻土地基和路基的不均匀变形导致半刚性基层沥青路面开裂严重.通过钢丝网加筋水泥稳定碎石梁弯曲试验,分析了钢丝网加筋位置、成网方式、直径、类型、间距等因素影响.试验得出,采用搭接成型的钢丝网,布设在距梁底面2.5 cm位置时,可以有效提高加筋梁的弯拉强度与挠度变形;与未加筋基件相比,设置加筋钢丝网后,水泥稳定碎石梁的性能得到大幅度提升,加筋效果明显;随着直径的增加,高碳钢丝网与镀锌低碳钢丝网的弯拉强度均增大;镀锌低碳钢丝网对弯拉强度的提升效果优于高碳钢丝网;不同直径钢丝分别对应最佳的钢丝网间距,在最佳间距时弯拉强度最优.结果表明,加筋钢丝网可以起到荷载扩散作用,提高水泥稳定碎石的整体承载能力.     

基于振动成型的级配碎石路用性能及设计标准

采用不同成型方式,研究对比了级配碎石的物理力学特性。提出了基于振动成型的级配碎石设计指标及设计标准,并应用实体工程进行验证。研究结果表明,提出的振动成型方式与现场碾压方式更为匹配,与重型击实相比,振动法设计的级配碎石最大干密度系统有所提高;CBR、抗变形能力等力学指标明显优于重型击实法设计的级配碎石。实体工程表明,振动成型设计的级配碎石为基层的复合式路面路表弯沉与半刚性基层路表弯沉相当;不需特殊设备,采用改进的施工工艺,现场含水量、级配及压实度均能够达到研究提出的振动成型设计标准。     

Sensitivity analysis of parameters for multi-stand roll forming using a new booting model

Multi-stand roll forming is a process that has very complicated deformation behaviour and shows significant nonlinearity.In this paper, the sensitivity analysis of parameters for multi-stand roll forming was performed via a new booting finite element method(FEM) model.Compared with the most of simulation, the new model is more consistent with production process and can account for the effects of roll rotating speed.Based on the model, the process of an open section channel formed with 10 passes was simulated and the sensitivity analysis was conducted with orthogonal experiment design combined FEM model.The multi-stand roll forming process can be efficiently analyzed by the new booting model.And sensitivity analysis shows the hardening exponent plays an important role in controlling the quality of the products.     

Numerical study of the forming process of high frequency welded pipe

The roll forming process is applied to the manufacturing of high frequency welded (HFW) pipes,section steels,etc. In this paper,the roll forming process of the HFW pipe is simulated with the finite element method (FEM). A user-defined material routine of the commercial finite element code ABAQUS/Explicit is developed,and the mixed hardening constitution model is realized through the user-defined material routine. Based on the mixed hardening constitutive equation,the numerical simulation of roll forming pro...     

基于PROFInet的卧辊磨测控系统设计与仿真

以PROFInet以太网通信技术为基础，完成了卧辊磨粉磨测控系统的整体设计，对PROFInet设备的封装、测控系统中PROFInet设备的互联以及现场设备的实现进行了描述。在此基础上，提出了基于组态软件的仿真模拟PLC控制对象的方法，并给出了仿真系统的结构，分析了用组态软件MCGS虚拟PLC被控对象的仿真原理，并详细介绍了卧辊磨控制仿真系统的开发过程。     

Engineering design optimization based on intelligent response surface methodology

An intelligent response surface methodology （IRSM） was proposed to achieve the most competitive metal forming products, in which artificial intelligence technologies are introduced into the optimization process. It is used as simple and inexpensive replacement for computationally expensive simulation model. In IRSM, the optimal design space can be reduced greatly without any prior information about function distribution. Also, by identifying the approximation error region, new design points can be supplemented correspondingly to improve the response surface model effectively. The procedure is iterated until the accuracy reaches the desired threshold value. Thus, the global optimization can be performed based on this substitute model. Finally, we present an optimization design example about roll forming of a ＂U＂ channel product.     

扭转梁式后悬架结构参数对侧倾振动影响

建立了包含扭转梁式悬架系统的整车8自由度平顺性模型和车辆瞬态侧倾模型,运用MATLAB/Simu-link仿真分析了扭转梁式悬架系统对平顺性和车辆瞬态侧倾的影响,并进行平顺性随机输入行驶试验和稳态回转试验验证。研究表明:在积分白噪声仿真路面,扭转梁式悬架系统对垂向和纵向振动几乎没有影响,但对侧倾振动动态性能具有重要影响,如固有频率、峰值时间、最大超调量等;揭示了扭转梁式悬架的扭转刚度、纵臂长度与车身侧倾角、车身侧倾固有频率、瞬态侧倾特性等之间的关系,为平顺性和操稳性协同优化设计奠定了基础。     

含Josephson结电路的混沌形成过程

用数值模拟方法研究了含Josephson结电路的动力学行为.根据电路模型和基尔霍夫定律建立系统的动力学方程,求出系统的平衡点,利用系统的相平面图、分岔图和Lyapunov指数图分析系统的混沌形成过程.为在此系统中避免混沌提供了直接的线索,为Josephson结器件稳定工作提供了有价值的参考.     

Sensitivity Analysis of Effect Related with Material Process and Assembly Variations to Loads Deformation and Stress on HSS Stamping Die

During stamping process, the material properties, process design parameters and production environments inevitably have variation and noisy factors, which possibly affect the sheet metal formability and the deformation of the die structure.After gaining a success in applying sheet metal forming numerical simulation analysis to get the forming loads during stamping process, a methodology of die structure analysis based on sheet metal forming simulation was proposed and validated by experiments.Based on these results, the effect related with initial blank thickness, blank holder force, blank positioning error and die alignment error variations to a DP600 hyperbolic bottomed cup drawing die's forming loads(especially unbalanced loads), and deformation and stress was studied numerically.The influence level of these variations to the die's forming loads, deformation and stress was disclosed.The findings can guide die design, die tryout and process control for high-strength steel(HSS) stamping with increased forming load and decreased sheet metal formability.     

Experimental Investigation into the Effect of Roll Amplitude on Roll Damping

An in-house large eddy simulation(LES) code has been developed in the previous study. In order to validate the code for simulation of roll motion, effect of roll amplitude on forced roll damping is experimentally investigated in a circulating water channel at Shanghai Jiao Tong University(SJTU). KRISO very large crude carrier 2(KVLCC2) is taken as a target ship, and a model with a scale of 1 : 128.77 is manufactured. Tests are carried out for the ship model at shallow draft with frequencies around its natural roll frequency, where natural roll frequency is attained via free roll decay. Six forced roll tests with roll amplitudes ranging from 1?to 4?are performed experimentally, and three forced roll motions are simulated with the in-house LES code for middle section of the ship model. Discrepancies between the computed roll damping coefficients and the ones from forced roll tests are quite small. By means of particle image velocimetry(PIV), velocity fields in the vicinity of the ship model, and generation and evolution of vortices near the ship bilge are measured in detail. It is shown that roll amplitude has a significant effect on the vortex behavior, and therefore on the magnitude of roll damping coefficient. Further experimental and numerical investigation into roll motions with large amplitudes is planned.     

Numerical analysis of unconventional forging process of hollowed shaft from Ti-6Al-4V alloy

This paper presents theoretical analysis of unconventional forging process of hollowed shaft from Ti-6Al-4V alloy in a three-slide forging press. This method in comparison with other metal forming methods allows for obtaining of hollowed products. The designed process is verified theoretically by means of numerical simulations based on finite element method with assumption of 3D state of strain. The following factors are considered in the analysis: material flow kinematics, strain distribution, temperature distribution and force of process. On the basis of results, it is stated that the application of designed technology allows for obtaining of a product of assumed quality. A comparison is made between material consumption in analyzed process and material consumption in typical metal forming methods, also in used at present technology of shaft manufacturing by machining only. It is stated that the application of forging in the three-slide forging press allows for a considerable decrease of manufacturing costs due to material savings and decrease of labor consumption of operations at finishing.