جستجوی مقالات مرتبط با کلیدواژه "fatigue analysis" در نشریات گروه "مکانیک"

The suspension system, one of the essential parts of any vehicle which has a significant role in vehicle steering, accelerating, and braking. One of the suspension system's main components is the trailing arm, which is exposed to frequent loadings and is made by welding method. Due to the use and nature of this piece, its fatigue analysis is crucial. Since this part is made by welding process, its fatigue analysis is much more complicated than other parts. In this paper, fatigue life of the trailing arm is investigated by using different numerical method. At first, safety factor of the component is calculated using dang van criteria. Dang van is one of the most famous and appropriated method for multi axial non proportional loads. However it is not a good criterion in order to calculate the damage of the weld line. So Volvo method that developed base on the weld process and properties is consider for fatigue analysis of the weld line. The obtained results improve the necessity of using this kind of method for welding process.  Finally, it could be concluded that for fatigue analysis of a welded component such as trailing arm, using both method are necessary. Considering two different criteria for a component and comparing the obtained results of the trailing arm under non proportional applied load is one of the achievement of this paper. Of course by using this method, the calculated fatigue life of the trailing arm is accurate. At the end, it should be noted that the both applied methods, Dang Van and Volvo, are completely verified by the available experimental result in the reliable references.

In this study, the dynamic behavior of the propulsion system of a VLCC (Very Large Crude oil Carrier) ship is investigated using a multi-input multi-output model. In this system the engine ordered speed and the number of active cylinders are assumed as inputs and the dynamic parameters of the engine such as torque and speed are considered as outputs. In this research, the effects of sea wave and wind on the system dynamic behavior have been investigated. In addition, the ship powertrain system is investigated in which the intermediate shaft and propeller shaft are analyzed using lumped parameter method, finite element method, distributed-lumped method and the results of these modeling techniques are compared to the modeling results in which the connecting shafts were considered as rigid body. Comparison of the results shows that there are significant differences between the results of rigid body method and other three types of system modeling. On the other hand, the time required to run the distributed-lumped model is much shorter compared to other methods that are considered in the study for the dynamic behavior of the ship's powertrain systems. On the other hand, the fatigue analysis of the ship power transmission shafts shows that the fatigue life assessment of these shafts is of great importance and should be considered in the design phase.