富康轿车进水后排气管冒黑烟

故障现象:车被水淹后连杆扭曲,对发动机进行大修。冷车无法着车,检查发现汽缸内燃油过多,拔下喷油器线可以着车,热车排气管冒黑烟,并且还有突突声,故障灯点亮。故障诊断:首先用诊断仪调取故障码,显示为历史故障码。喷油时间4.4min,转 速880r/min,混合气过稀,检查 ECU 到氧传感器线路。 读数据流发现,氧传感器电压为930mV,喷油时间为 3.1ms,进气压力为54.1kPa。从数据可以看出,混合气浓, 接上油压表测量,怠速下油 压为280kPa,远远高于200kPa 标准值。接上真空表测量真空度为 45kPa,低于正常值 58～72kPa。从真空度判断油 …     

乳化橡胶沥青水泥砼疲劳性能及应用研究

论述乳化橡胶沥青水泥砼的弯曲疲劳试验结果及疲劳方程，通过对试件疲劳寿命的修正推导抗弯拉强度结构系数方程，结合试验路工程，对ＥＲＡＣＣ路面及造价进行初步分析。     

顶推船队安全过弯的引航模型研究

根据船队在弯曲航段的运动特征，分析了船队过弯曲航道的数学模型；结合实船试验对模型进行了论证，得出船队过弯曲航道的一般规律。     

The effect of plastic constraint on the initiation of ductile tears in shipbuilding structural steels

In this paper, the effect of plastic constraint on the initiation of ductile tears in four different shipbuilding structural steels has been experimentally studied by measuring the J-integral and crack opening displacement COD at initiation in three-point bend specimens with deep and shallow notches. Experimental results of seven groups of different strength alloy steels show that both Si and Ji values of ductile tear from the shallow crack specimens which have less constraint flow field are significantly higher than those of deeply notched specimens. Slip-line-field analysis shows that, for shallow crack, the hydrostatic stress is lower than that from standard deeply cracked bend specimen, which develops a high level of crack tip constraint, provides a lower bound estimate of toughness, and will ensure an unduly conservative approach when applied to structural defects, especially if initiation values of COD and J-integral are used.     

水面舰艇总体弯曲变形对纵向布置曲柄摇杆机构设计的影响

在水面舰艇机械的传统设计中一般不考虑机架伸缩变形对机构运行的影响。事实上，水面舰艇的纵向弯曲变形会使沿舰体纵向布置曲柄摇杆机构的机架产生一定程度的伸长和缩减。机架这种伸缩会直接影响特殊曲柄摇杆机构的正常运行。为了避免水面舰艇总体弯曲变形对曲柄摇杆机构运行的影响，本文提出一组适用于沿水面舰艇纵向布置曲柄摇杆机构设计的简易公式。