نوع مقاله : مقاله پژوهشی
دانشکده مهندسی مکانیک، دانشگاه بوعلی سینا، همدان
عنوان مقاله [English]
Engineering components and structures are often subjected to cyclic loads. Vehicle manufacturers continuously develop new vehicles with more luxury, convenience, performance, and safety. Vehicle components are redesigned which results in increased performance. Therefore, the design should be implemented based on conflicting constraints, designing conditions and uncertain factors to obtain optimized and feasible performance. The interaction of the vehicle and steering system is important to evaluate the vehicle on-center handling. The outer tie rod is one of the important parts in the steering system. It plays a crucial role in vehicle safety and stability and implies a good driver experience. An outer tie rod as the part of the steering kinematic chain is employed to transfer the motion to tires and to support the load and torque induced by bumping, braking, and accelerating conditions. Fatigue cracks are initiated and grown in the outer tie rod due to the effects of cyclic loads. This phenomenon has created serious problems in the safety of passengers. The fatigue of outer tie rod in Peugeot 405 steering system was studied by the finite- element simulation and the experimental testing. The chemical composition and mechanical properties for the material of outer tie rod were determined. Then, fatigue under conditions similar to reality was simulated by the finite-element software ABAQUS. Three different modes of the loading with the 23, 28, and 57 kN were simulated in the same condition and the fatigue life was calculated in each of these three cases. In experimental study, the specimens were tested under the similar conditions with the simulations of determining the fatigue life. The fatigue life was measured in fatigue test with a constant load for all specimens. The good agreement was observed between the numerical and the experimental results. Finally, the fracture surface of the specimens was studied.