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91.
92.
液压转向系统冷启动沉故障在北方冬季是比较常见的一个故障,论文针对故障产生的机理进行了深入分析,并对产生故障的常见原因及改进方法进行了简单介绍,最后对如何确定故障源从测试方面提供了方法. 相似文献
93.
94.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5):704-732
A fault classification method is proposed which has been applied to an electric vehicle. Potential faults in the different subsystems that can affect the vehicle directional stability were collected in a failure mode and effect analysis. Similar driveline faults were grouped together if they resembled each other with respect to their influence on the vehicle dynamic behaviour. The faults were physically modelled in a simulation environment before they were induced in a detailed vehicle model under normal driving conditions. A special focus was placed on faults in the driveline of electric vehicles employing in-wheel motors of the permanent magnet type. Several failures caused by mechanical and other faults were analysed as well. The fault classification method consists of a controllability ranking developed according to the functional safety standard ISO 26262. The controllability of a fault was determined with three parameters covering the influence of the longitudinal, lateral and yaw motion of the vehicle. The simulation results were analysed and the faults were classified according to their controllability using the proposed method. It was shown that the controllability decreased specifically with increasing lateral acceleration and increasing speed. The results for the electric driveline faults show that this trend cannot be generalised for all the faults, as the controllability deteriorated for some faults during manoeuvres with low lateral acceleration and low speed. The proposed method is generic and can be applied to various other types of road vehicles and faults. 相似文献
95.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(12):1622-1641
Wheel set flange derailment criteria for railway vehicles are derived and the influence of wheel–rail contact parameters is studied. An indirect method for wheel–rail force measurement based on these derailment evaluation criteria is proposed. Laboratory tests for the calibration of strain–force devices on the bearing box are carried out to determine the relationship between the applied force and the measured strain. The simulation package, SIMPACK, is used to develop a passenger car model to generate wheel–rail forces and vibration signals. Different cases are considered in this model to provide an accurate validation of the identified wheel–rail forces. A feasibility test is conducted in the Beijing Loop test line using a passenger car equipped with a set of strain gauges on the wheel set. The comparison of the force time history applied to the instrumented wheel set and that obtained using the indirect method is presented. 相似文献
96.
为探讨不同场景中行人群组运动的微观特征,并比较不同类型群组运动差异,本文通过大学校园内楼梯上及通道内的观测实验,获取行人运动的相关数据,研究了群组大小、社会关系、运动场景和性别对群组运动的影响. 结果表明:大学校园内行人成组比例低于商场周围行人成组比例;群组成员间的交流方式等因素会影响群组构型;由于群组成员越多相互协调就越困难,所以群组规模越大,其速度越小;此外,男性群组速度大于女性群组速度,情侣间频繁的交流也会对其速度产生负面影响;就差异性而言,2 人和3 人群组间的速度差异小于单人和2 人群组间的速度差异;单个行人不同性别间的速度差异大于2 人和3 人群组不同性别间的速度差异;楼梯上单人与群组的速度差异没有通道内明显. 相似文献
97.
网络计划工期-费用的动态规划决策 总被引:1,自引:0,他引:1
杨家祥 《交通部上海船舶运输科学研究所学报》1996,(1)
关键路线法中网络计划工期-费用优化,可以化为一系列单阶段决策,构成确定性离散优化决策问题,本文试用动态规划处理这一过程。 相似文献
98.
Ney Roitman Carlos Magluta Ronaldo C. Batista Ricardo W. Capllonch 《Marine Structures》1996,9(10):991-1002
The structural elastic behaviour of steel pipelines during on-bottom pull-in procedure is investigated experimentally by using small scale models. Despite the lack of a sea-bed soil pipeline interaction effect in the model, it is possible to show that the unevenness of the sea-bed surface and the non-uniform distribution of friction forces can lead to large deflection bending stresses, higher than the numerical results yielded by standard software packages commonly used for design calculations. Due to foreseen difficulties in overcoming the drawbacks in practical and numerical procedures, the off-bottom pull-in operation arises as an attractive alternative even for shallow waters. 相似文献
99.
基于余度概念的受损船体总纵剩余强度预报 总被引:5,自引:0,他引:5
基于作者提出的结构余度概率衡准,并通过对船体构件损伤模型与船体总纵强度可靠性计算模型的讨论,本文建立了一个合理而筒便的受损船体总纵剩余强度预报方法。 相似文献
100.
带纵骨实肋板式耐压液舱壳板强度计算方法研究 总被引:6,自引:1,他引:6
本文把耐压液舱结构看成一弹性整体,先对其进行整体求解,然后再对耐压液舱壳板按具有初始膜应力的混合边界问题求解。结果表明:在弹性范围内,本文方法计算值与有限元计算值及实验值吻合较好;在弹塑性范围内,本文对耐压液舱壳板边界约束的处理比文献「1」方法更符合弹塑性状态时其边界约束的真实状况。 相似文献