双端制动器惯性试验台的设计

随着我国汽车工业的迅猛发展,汽车产量不断增多,车速越来越高,对汽车制动性能要求也越来越高。汽车制动器是汽车上的重要设备,其质量的好坏影响着行车的安全。电惯量模拟是近几年兴起的一种比较先进的负载模拟方法,文章就制动器惯性试验台系统结构以及电惯量模拟的方法进行了比较详细的说明。     

高钒高速钢碳化钒形态的数值化分析

针对碳化钒的不同形态,设计出定量分析软件,并利用形状因子K,实现了高钒高速钢不同碳化物形态数值化处理,当K介于0.785～1.000之间碳化钒形态为团球状;K≤0.223,碳化钒呈开花状.高钒高速钢当碳含量达到4.2%时,K为0.86和当量直径D为0.78μm,碳化物呈团球状均匀分布.     

CA6140车床数控改造中机械装置设计技巧

介绍了普通车床数控改造中机械装置的几个独特设计，使得数控车床纵向进给系统结构更简单、性能更可靠、装拆更方便。     

On Controllability of Switched Linear Systems

This paper investigates the number of switchings and design of switching sequences for controllability of switched linear systems. Two related results are established. One is a new constructive approach to designing switching sequences. The controllable state set of each switching sequence designed via the approach coincides with the controllable subspace of switched linear systems. The other is a well-estimated value for the minimum number of switchings required for controllability. Each state in the controllable subspace can be steered to origin within this value of switching times.     

间隔ν-支持向量机及其几何问题

提出总间隔ν=支持向量机(TM-ν-SVM),该算法可取得比ν-SVM更好的理论分类性能.研究表明TM-ν-SVM等价于求解特征空间中的两个压缩凸包的最近点对.讨论压缩凸包的相关性质,并给出对应的几何算法.数值模拟实验表明TM-ν-SVM和对应的几何算法可取得比其它算法更好的性能.     

基于人工免疫的网络安全态势评估模型

本文将人工免疫原理应用到网络安全态势评估的研究中.通过对入侵检测模型中有关自体、非自体、抗原的形式化描述,建立了抗体细胞的演化机制、动态免疫记忆、免疫监视等免疫机制.依据人体免疫系统抗体浓度的变化与病原体入侵强度的对应关系,建立了网络安全态势实时定量计算模型.     

基于嵌入式的悬架与转向集成控制器研究

为了改善车辆的操纵稳定性和行驶平顺性,提高汽车底盘控制的集成度,本文对底盘部分的半主动悬架SASS (Semi Active Suspension System)和电动动力转向EPS (Electric Power Steering)系统进行了集成控制研究.设计并试制出基于嵌入式系统ARM S3C44BOX的SASS和EPS集成控制器,并进行了台架试验,结果表明研制的集成控制器效果良好,可用于汽车底盘集成控制系统的开发研究.     

Research on the Mechanical Properties of Magnetorheological Damping and the Performance of Microprobe Test Process

Journal of Electronic Testing - In order to control the stable and controllable loading of the wafer level microprobe test bench, the magnetorheological (MR) damper used in the existing research...     

Finite element implementation of a thermo-damage-viscoelastic constitutive model for hydroxyl-terminated polybutadiene composite propellant

A thermo-damage-viscoelastic model for hydroxyl-terminated polybutadiene (HTPB) composite propellant with consideration for the effect of temperature was implemented in ABAQUS. The damage evolution law of the model has the same form as the crack growth equation for viscoelastic materials, and only a single damage variable \(S\) is considered. The HTPB propellant was considered as an isotropic material, and the deviatoric and volumetric strain-stress relations are decoupled and described by the bulk and shear relaxation moduli, respectively. The stress update equations were expressed by the principal stresses \(\sigma_{ii}^{R}\) and the rotation tensor \(M\), the Jacobian matrix in the global coordinate system \(J_{ijkl}\) was obtained according to the fourth-order tensor transformation rules. Two models having complex stress states were used to verify the accuracy of the constitutive model. The test results showed good agreement with the strain responses of characteristic points measured by a contactless optical deformation test system, which illustrates that the thermo-damage-viscoelastic model perform well at describing the mechanical properties of an HTPB propellant.