Component Fatigue Behaviors And Life Predictions Of A Steering Knuckle Using Finite Element Analysis
The paper describes a vehicle steering knuckle undergoing time-varying loadings during its service life. Fatigue behavior is, therefore, a key consideration in its design and performance evaluation. This paper is aimed to assess fatigue life and compare fatigue performance of steering knuckles made from three materials of different manufacturing processes. These include forged steel, cast aluminum, and cast iron knuckles. In light of the high volume of forged steel vehicle components, the forging process was considered as base for investigation. Static as well as baseline cyclic deformation and fatigue properties were obtained and compared. The paper envisages that in addition, referring a number of load-controlled fatigue component tests conducted for the forged steel and cast aluminum knuckles. Finite element models of the steering knuckles were also analyzed to obtain stress distributions in each component. Based on the results of component testing and finite element analysis, fatigue behaviors of the three materials and manufacturing processes are then compared. The paper concludes with that forged steel knuckle exhibits superior fatigue behavior, compared to the cast iron and cast aluminum knuckles.
STRUCTURAL FATIGUE TESTS OF AUTOMOBILE COMPONENTS UNDER CONSTANT AMPLITUDE LOADINGS. IN: FATIGUE LIFE: ANALYSIS AND PREDICTION
This paper presents fatigue strength evaluations of various structural components of automobiles under constant amplitude loadings with a closed loop servohydraulic structural fatigue testing machine. Structural fatigue tests of rear axle housings of automobiles were performed. Acceptance criteria for the axle housing were decided by the actual proving ground running test and statistical analysis of results. Durability evaluations of axle housings for 8-ton trucks were conducted. The weak spot of axle housings was the heat affected zone in weldment. Torsional fatigue tests on a turbocharged diesel engine crankshaft were performed. Most cracks initiate at the oil hole and propagate along the maximum tensile stress planes. Fatigue strength evaluations of automobile components were also performed for their structural reliability in service. The constant amplitude fatigue testing method is quickest when a proper acceptance criterion is decided or known.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.