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991.
车轮外倾角与车轮前束值是车轮定位中的两个重要参数,车轮前束是为了抵消车轮外倾产生的侧滑不利影响,因此前束值要与车轮的外倾角有合理的匹配。综合考虑车辆的结构参数和轮胎特性,基于车轮的侧滑机理,推导出车轮外倾角与前束值的合理匹配关系模型,用试验结果验证了模型的正确性,为在车辆的设计开发过程中,合理的确定车轮的外倾角与前束值提供理论参考。  相似文献   
992.
Ever since vehicle noise, vibration, and harshness (NVH) reduction technology made dramatic improvements, vehicle interior noises represented by Squeak and Rattle (S/R) becomes an ever more important factor to improve the emotional quality of vehicles. Generally, people detect S/R noises on automotive interior parts, brake system, suspension, Body in White (BIW), etc. Among them, the rear-glass joint is a major source for vehicle interior noise, and can cause S/R noises under a variety of environmental and driving conditions. This study uses, two approaches, experimental and numerical approaches, to define the cause of S/R noise at the rear-glass section. Based on these two approaches, this study confirms that S/R noises generate through the contact between bottom side of molding and BIW. The sealant penetration length, panelmolding distance, and sealant width are the parameters affecting noise generation. In addition, this study created an optimal design with Design of Experiments (DOE) of the rear-glass joint. The design maximized the sealant penetration length, which is a parameter that majorly affects noise. The optimal design comprises of two steps: sealant injections shape optimization and rear-glass joint parameter optimization. Each step is carried out with FEA and validated by sealant penetration experiments. Through these optimizations, this study obtained an optimum combination of design parameters and fignificantly reduced the noise generated by rear-glass section.  相似文献   
993.
基于CORBA的分布式作战系统初探   总被引:1,自引:0,他引:1  
根据分布式作战系统的特点,提出了一种利用CORBA技术实现的分布式作战系统框架.该框架采用多客户机、多服务器的模式,实现了数据处理和应用的分离,提高了系统的互操作能力.  相似文献   
994.
Compared with internal combustion engine (ICE) vehicles, four-wheel-independently-drive electric vehicles (FWID EV) have significant advantages, such as more controlled degree of freedom (DOF), higher energy efficiency and faster torque response of an electric motor. The influence of these advantages and other characteristics on vehicle dynamics control need to be evaluated in detail. This paper firstly analyzed the dynamics characteristics of FWID EV, including the feasible region of vehicle global force, the improvement of powertrain energy efficiency and the time-delays of electric motor torque in the direct yaw moment feedback control system. In this way, the influence of electric motor output power limit, road friction coefficient and the wheel torque response on the stability control, as well as the impact of motor idle loss on the torque distribution method were illustrated clearly. Then a vehicle dynamics control method based on the vehicle stability state was proposed. In normal driving condition, the powertrain energy efficiency can be improved by torque distribution between front and rear wheels. In extreme driving condition, the electric motors combined with the electro-hydraulic braking system were employed as actuators for direct yaw moment control. Simulation results show that dynamics control which take full advantages of the more controlled freedom and the motor torque response characteristics improve the vehicle stability better than the control based on the hydraulic braking system of conventional vehicle. Furthermore, some road tests in a real vehicle were conducted to evaluate the performance of proposed control method.  相似文献   
995.
《思想道德修养与法律基础》是高等学校思想政治理论课程的重要组成部分。本文通过分析高职高专《思想道德修养与法律基础》课的现状,针对高职高专人才培养目标提出构建传统教学模式与多元教学方式兼顾,校内实践与社会实践兼顾,基本素养与职业素质兼顾——三位一体的《思想道德修养与法律基础》课教学模式,以期提高《思想道德修养与法律基础》课的教学实效性。  相似文献   
996.
道路是城市的动脉,沥青路面因其噪音低、舒适性高的特点得以在市区快速推广。该文以惠州市的市区沥青路面的病害为例,总结了市区沥青路面病害的特点、成因及处置维修措施。对城市沥青路面的管养维护总结了较丰富的实践经验,以供同行借鉴。  相似文献   
997.
本文通过作者对日本卧式加工中心的大修改造,分析了造成高精度机床精度丧失的原因和其对应的解决方法,为高精度机床的使用、维护保养以及大修改造指出了有实际意义的思路。  相似文献   
998.
研究目的:遵循"以人为本、服务运输、强本简末、系统优化、着眼发展"的设计理念,结合合肥枢纽的现状,统筹考虑枢纽在建项目、拟建项目及规划项目,系统研究确定推荐方案及重大比选方案,为枢纽总图研究及设计积累经验。研究结论:随着合肥南站的建设,枢纽形成了两大客站的格局,以此为前提,研究了集中引入合肥南站方案、商阜杭引入合肥站方案、商阜杭引入合肥南站方案和商阜杭新建客站方案四大系列方案。经研究比选,集中引入合肥南站方案在运输组织、旅客出行、点线能力协调等方面具有明显的优势,但合肥南站已经开工建设,对其进行调整存在不确定性,因此建议下阶段根据合肥南站工程调整的可能性对集中引入合肥南站方案、商阜杭引入合肥站方案进一步深入研究比选。  相似文献   
999.
Wave propagation in an infinite elastic piezoelectric medium with a circular cavity and an impermeable crack subjected to steady-state anti-plane shearing was studied based on Green's function and the crack-division technique. Theoretical solutions were derived for the whole elastic displacement and electric potential field in the interaction between the circular cavity and the impermeable crack. Expressions were obtained on the dynamic stress concentration factor (DSCF) at the cavity's edge, the dynamic stress intensity factor (DSIF) and the dynamic electric displacement intensity factor (DEDIF) at the crack tip. Numerical solutions were performed and plotted with different incident wave numbers, parameters of piezoelectric materials and geometries of the structure. Finally, some of the calculation results were compared with the case of dynamic anti-plane interaction of a permeable crack and a circular cavity in an infinite piezoelectric medium. This paper can provide a valuable reference for the design of piezoelectric actuators and sensors widely used in marine structures.  相似文献   
1000.
Numerical simulation of the anti-shock performance of a gear case   总被引:1,自引:0,他引:1  
Both sea battles and testing of ship in underwater explosions reveal unacceptably poor anti-shock performance of important shipboard equipment. Anti-shock performance of shipboard equipment is a significant factor determining fighting strength and survivability. The anti-shock performance of a shipboard gear case based on BV043/85 was investigated using numerical simulation. A geometric model of the gear case was built using MDT software and meshed in HyperMesh software, and then the finite element model of the gear case was formed. Using ABAQUS software, the anti-shock performance of the gear case was simulated. First, shock response of typical regions of gear case was determined. Next, some generalizations were made about the anti-shock performance of the gear case by analyzing the Mises stress of typical regions varied with shock inputs. Third, weak regions were determined from simulation results. The threshold values of shock resistance of the gear case at different impulse widths were obtained through interpolating the numerical simulation results selected from the most dangerous spot. This research provides a basis for further optimization of the design of gear cases.  相似文献   
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