Energy Criterion of the Reliability of Structural Elements in Vehicles
- PDF / 701,491 Bytes
- 6 Pages / 594 x 792 pts Page_size
- 6 Downloads / 206 Views
ENERGY CRITERION OF THE RELIABILITY OF STRUCTURAL ELEMENTS IN VEHICLES V. A. Ogorodnikov,1,2 N. S. Grechanyuk,1 and A. V. Gubanov1
UDC 621.983.3.044.002
We study the process of wear of the fifth wheel of an articulated road train in order to determine its residual life. For this unit, we obtain the energy criterion of wear with an aim to determine the parameters affecting its service life. Keywords: impact loading, experimental-numerical method, hardness method.
The motor transport plays an important role in the national economy. However, the number of traffic accidents increases with the number of vehicles on the roads. If we want to decrease the number of accidents and their heaviness, then it is necessary to develop safe structures. In the analysis of accidents of this kind and, hence, the safety of the design of vehicles, it is customary to use various velocity and energy criteria [1–3]. As the main causes of accidents with road trains, we can mention their rollovers, skidding, and disconnection of semitrailers [4]. The so-called fifth-wheel unit including the pin–clamp couple proves to be one of the crucial elements in their design responsible for the safety of operation. In the course of operation, this element suffers alternating dynamical loads, which leads to the intense wear of cylindrical surfaces operating under the conditions of friction. The producers of elements of the fifth wheel indicate the ultimate parameters of wear. If they are attained, then the elements should be replaced. However, these parameters are, in fact, not established experimentally. Hence, they are set subjectively and often a priori. Methods of Investigations To study the stress-strain states in the plastic region, we use a hardness efficient method [5] aimed at getting the experimental data on the hardness of the worn-out material. In the course of operation of structural elements, the material is hardened in the deformed zone. Therefore, it becomes to restore its energy characteristics and, in particular, the energy spent on deformation. The possibilities of determination of the stress intensity σ i according to the distribution of hardness in the deformed materials were experimentally substantiated in [6]. In the present work, this method is used to study various technological problems [7–9]. In the experimental substantiation of the method, it is of great importance to clarify whether there exists a single curve connecting the level of hardness with the stress intensity for various stressed states and histories of deformation. In most cases, in order to solve this problem, we tested thin-walled tubular specimens of various materials under the combined action of torsion, tension, and internal pressure. The specimens were studied under the conditions of monotonic deformation ( σ1 /σ 2 = const, – 1 ≤ σ 2 /σ1 ≤ 0). It was discovered that, 1 2
Vinnitsa National Technical University, Vinnitsa, Ukraine. Corresponding author; e-mail: [email protected].
Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 53, No. 5, pp.
Data Loading...
