浅谈车辆的驻车制动

1概述 机动车辆的制动系统的主要作用是使行驶的车辆减速或停车,并在驾驶员离车在情况下车辆停止不动。因此,制动系至少应该有两套独立的制动系驱动装置：行车和驻车制动装置。而驻车根据使用情况分为轮边制动和中央制动（俗称“手刹”）。     

翻边成型中预示修边线的一种简便方法

提出了一种在伸长／收缩翻边成型中合理预示修边线位置的迭代算法，在该算法中，采用了全量塑性理论及膜应变假定，并考虑了板材的厚向向各向异性，可以直接从所需的翻边高度计算出初始坯料的尺寸。通过与实验结果相比，证明了该算法的有效性。     

汽车偏置前撞试验用渐变强度可变形壁障的有限元模型

建立了渐变强度可变形壁障(PDB)的有限元模型。PDB的两个铝蜂窝芯采用壳单元并用"等同化"方法使之与实际的蜂窝结构一致,铝蜂窝窝孔中的空气采用阻尼杆单元表示。对PDB偏置板和横梁的碰撞实验过程进行了仿真,结果表明测力墙受力和壁障碰撞后变形与实验结果高度吻合,验证了模型的正确性。     

Study on Factors Affecting Springback and Application of Data Mining in Springback Analysis

Springback of sheet metal induced by elastic recovery is one of major defects in sheet metal forming processed. Springback is influenced by many factors including properties of the sheet material and processing conditions. In this paper, a springback simulation was conducted and comparisons between the results based on different processing variables were illustrated. The discovery of knowledge of the effects of geometry and process parameters on springback from FEM results becomes increasingly important, as the number of numerical simulation has grown exponentially. Data mining is an effective tool to realize knowledge discovery in simulation results. A datamining algorithm, rough sets theory (RST), was applied to analyze the effects of process parameters on springback in U-bending.     

Polycrystalline behavior analysis of extruded magnesium alloy AZ31

Uniaxial tensile and compressive tests were performed at room temperature on extruded AZ31 Mg alloy specimens and distinct tensile-compressive anisotropy was detected. Deformed specimens were examined and the results indicate that the generation of {10 $\bar 1$ 2}〈10 $\bar 1$ 1〉 twin is responsible for the mechanical anisotropy. A rate independent crystal plasticity model, which accounts for both slip and twinning, was developed for polycrystalline hexagonal close packed (HCP) materials. Model predictions for the stress-strain curves and texture evolution were in reasonable agreement with the experimental results. Specifically, the model captured the three stages of strain hardening for uniaxial-compression. By comparing stress-strain curves and texture evolution between model predictions and experimental measures, information about the dominant slip and twinning systems active at room temperature was deduced.     

A Methodology for Curve and Surface Fitting with Adaptive Fairing for Digitized Points

Introduction In the process of part or product design, re-verse engineering is a method for constructing aCAD model from the physical part that already ex-ists[1-4]. The whole process starts from digitizingthe part, i.e., the measuring of coordinates of t…     

Application of Decision Tree Algorithm in Stamping Process

Introduction Learning is the main symbol of human intelli-gence and the basic means to acquire the knowl-edge. Machine learning can extract the rules hid-den in data through analyzing the relations amongobjects, which is also computational theory to in-vestigate learning. Nowadays, various methodsare adopted in machine learning field, such as deci-sion tree, Bayesian classification, neural network,genetic algorithm and rough set[1]. Many machinelearning methods have been used as the convenien…     

我国企业财务管理目标的选择

财务管理目标是企业理财活动所希望实现的结果,是评价企业理财活动是否合理的基本标准,本文介绍了五种比较主要的财务管理目标,并进行了评价,在借鉴了国外两种主要的财务管理模式后,提出了我国企业财务管理的目标为企业价值最大化。