A process sequence design on the forming process of disk-brake piston

A design methodology is applied to manufacturing a disk-brake piston component. A rigid plastic finite element method is applied to simulate the conventional four-stage manufacturing process and the one-step process from a selected stock to the final product shape for information on metal flows. Two-stage forming operations with different punch corner and nose radii are also simulated to identify the best possible solutions. The best manufacturing process is selected, which uses a hemispherical punch in the drawing process. Experiments are conducted for comparison with the numerical results. The good agreement between the experimental and numerical results validates the design methodology using the finite element method.     

A hybrid intelligent method for modelling the EDM process

This paper discusses the development and application of a hybrid artificial neural network and genetic algorism methodology to modelling and optimisation of electro-discharge machining. The hybridisation approach is aimed not only at exploiting the strong capabilities of the two tools, but also at solving manufacturing problems that are not amenable for modelling using traditional methods. Based on an experimental data, the model was tested with satisfactory results. The developed methodology with the model is highly beneficial to manufacturing industries, such as aerospace, automobile and tool making industries.     

Modelling of Manufacturing Systems Complexity

This research aims at understanding the effects of human worker attributes within the manufacturing system. The system must balance human characteristics, needs, skills and capabilities within the technical and business environment, in order to be effective. A model is needed to provide insights into the sensitivities of the manufacturing system. A methodology to systematically determine the product and process complexity for any manufacturing environment was introduced - a rapid Manufacturing Complexity Assessment Tool (MCAT). The complexity model is based on three elements: total quantity of information, diversity of information and the information content which corresponds to the effort to produce a feature within a product. Product and process complexity are decoupled and treated independently in this analysis. An example is presented to illustrate the methodology for both. The purpose is to develop a tool that helps to identify areas of complexity that can be simplified.     

敏捷化智能制造单元及其关键技术

敏捷制造是21世纪新的制造模式，针对国内的情况，提出了敏捷化智能制造单元的概念，它融入了敏捷制造思想、制造单元技术和智能制造技术，它的建立分三个阶段，分别为准、正则与完全敏捷化智能制造单元分析了准敏捷化智能制造单元的特点，建立了它的功能模型，并用IDEFO的方法进行了描述，此外，还详细讨论了现阶段实现准敏捷化智能制造单元的关键技术，即，敏捷制造单元的重构、建模、控制和调度技术。     

基于Cu-Al-Fe合金的粉芯丝材增材制造理论及其温度场分析

目前有关粉芯丝材增材制造的研究较少，其理论尚不成熟.将Cu-Al-Fe合金作为研究对象，系统论述了粉芯丝材电弧增材制造的相关理论(沉积成形理论、梯度传热理论和晶粒细化理论)，并使用Simufact-Welding平台搭建了单道多层数值模型，通过对多组别温度场的分析，获得了试验条件下的最佳工艺窗口，即输入电流140 A和扫描速度0.4 m/min，最后开展了优化工艺窗口下的粉芯丝材沉积成形试验.结果表明，在此工艺窗口下可获得形状较好的薄壁墙，该研究为开展粉芯丝材电弧增材制造提供必要的理论基础与试验依据.     

Thermal process simulation of droplet based metal printing with aluminium

Droplet based additive manufacturing is a branch of novel processes to build full dense metal parts by adding material droplet by droplet on a build platform. As each droplet solidifies individually upon contact, the quality of bonding to the existing material is determined by the adjacent surface temperatures and the temperature of the arriving droplet. To design a manufacturing process that ensures good bonds between all droplets, it is necessary to understand the relations between process parameters, the part’s geometry and thermal conditions for each arriving droplet. This paper presents a thermal simulation model that is based on Flow 3D software. By adding a user routine to the solver, it is possible to simulate the building process of a part consisting of several thousand droplets with an acceptable effort. This simulation is used to study the effect of production parameters (substrate temperature, droplet temperature and deposition frequency) as well as the parts geometry (layer size and height) on the resultant temperature field. The model was successfully validated with experimental data and can deliver valuable information during further development of this additive manufacturing process.     

Estimation of cutting forces in micromilling through the determination of specific cutting pressures

In this paper a new model for the estimation of cutting forces in micromilling based on specific cutting pressure is presented. The proposed model includes three parameters which allow to control the entry of the cutter in the workpiece and which consider also the errors in the radial position of the cutting edges of the tool.

Due to the difficulties presented in the manufacturing of the micromilling tools, manufacturing errors frequently appear. These are errors in the radial and angular position of the cutting edge and have significant influence in the estimation of the instantaneous cutting force in micromilling.

The accuracy of the estimated parameters of the cutting force expression plays a major role in the resulting cutting force. For this reason, the influence of the fitting of the specific cutting pressure is analyzed.

The new mechanistic force model determines the instantaneous cutting force coefficients using experimental data processed for one cutter revolution. The model has been validated through experimental tests over a wide range of cutting conditions. The results obtained show good agreement between the predicted and measured cutting forces.     

基于无模铸型制造技术的复杂铸件快速制造

无模铸型制造技术是以树脂砂为成型材料，利用快速成型技术的离散／堆积成型原理，对三维CAD实体模型进行分层切片处理，得到不同高度截面层的信息，采用截面扫描、喷射固化工艺，直接获得树脂砂铸型或铸造模具的一种方法。在复杂铸件快速制造的实际应用中，无模铸型制造技术表现出造型材料易得、制造时间短、制造成本低、铸件质量好等优点，体现了快速敏捷制造的优势，也为快速成形技术在铸造中的应用开辟了一个新领域。